[MNG-8084] Make the v4 api usable outside the Maven runtime (#1441)

api/maven-api-core/src/main/java/org/apache/maven/api/services/PathSource.java

@@ -0,0 +1,53 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.api.services;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+class PathSource implements Source {
+
+    private final Path path;
+
+    PathSource(Path path) {
+        this.path = path;
+    }
+
+    @Override
+    public Path getPath() {
+        return path;
+    }
+
+    @Override
+    public InputStream openStream() throws IOException {
+        return Files.newInputStream(path);
+    }
+
+    @Override
+    public String getLocation() {
+        return path.toString();
+    }
+
+    @Override
+    public Source resolve(String relative) {
+        return new PathSource(path.resolve(relative));
+    }
+}

api/maven-api-core/src/main/java/org/apache/maven/api/services/SettingsBuilder.java

@@ -19,11 +19,13 @@
 package org.apache.maven.api.services;
 
 import java.nio.file.Path;
+import java.util.List;
 
 import org.apache.maven.api.Service;
 import org.apache.maven.api.Session;
 import org.apache.maven.api.annotations.Experimental;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.settings.Settings;
 
 /**
  * Builds the effective settings from a user settings file and/or a global settings file.
@@ -97,4 +99,37 @@ public interface SettingsBuilder extends Service {
             @Nonnull Path userSettingsPath) {
         return build(SettingsBuilderRequest.build(session, globalSettingsPath, projectSettingsPath, userSettingsPath));
     }
+
+    /**
+     * Validate the specified settings.
+     *
+     * @param settings The settings to validate, must not be {@code null}.
+     * @return The list of problems that were encountered, must not be {@code null}.
+     */
+    @Nonnull
+    default List<BuilderProblem> validate(@Nonnull Settings settings) {
+        return validate(settings, false);
+    }
+
+    /**
+     * Validate the specified settings.
+     *
+     * @param settings The settings to validate, must not be {@code null}.
+     * @param isProjectSettings Boolean indicating if the validation is for project settings or user / global settings.
+     * @return The list of problems that were encountered, must not be {@code null}.
+     */
+    @Nonnull
+    List<BuilderProblem> validate(@Nonnull Settings settings, boolean isProjectSettings);
+
+    /**
+     * Convert a model profile to a settings profile.
+     */
+    @Nonnull
+    org.apache.maven.api.settings.Profile convert(@Nonnull org.apache.maven.api.model.Profile profile);
+
+    /**
+     * Convert a settings profile to a model profile.
+     */
+    @Nonnull
+    org.apache.maven.api.model.Profile convert(@Nonnull org.apache.maven.api.settings.Profile profile);
 }

api/maven-api-core/src/main/java/org/apache/maven/api/services/SettingsBuilderException.java

@@ -18,6 +18,9 @@
  */
 package org.apache.maven.api.services;
 
+import java.util.List;
+import java.util.stream.Collectors;
+
 import org.apache.maven.api.annotations.Experimental;
 
 /**
@@ -27,13 +30,24 @@ import org.apache.maven.api.annotations.Experimental;
  */
 @Experimental
 public class SettingsBuilderException extends MavenException {
+
+    private final List<BuilderProblem> problems;
+
     /**
      * @param message the message to give
      * @param e the {@link Exception}
      */
     public SettingsBuilderException(String message, Exception e) {
         super(message, e);
+        this.problems = List.of();
     }
 
-    // TODO: add SettingsBuilderResult
+    public SettingsBuilderException(String message, List<BuilderProblem> problems) {
+        super(message + ": " + problems.stream().map(BuilderProblem::toString).collect(Collectors.joining(", ")), null);
+        this.problems = List.copyOf(problems);
+    }
+
+    public List<BuilderProblem> getProblems() {
+        return problems;
+    }
 }

api/maven-api-core/src/main/java/org/apache/maven/api/services/SettingsBuilderRequest.java

@@ -18,6 +18,7 @@
  */
 package org.apache.maven.api.services;
 
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Optional;
 
@@ -40,14 +41,6 @@ public interface SettingsBuilderRequest {
     @Nonnull
     Session getSession();
 
-    /**
-     * Gets the global settings path.
-     *
-     * @return the global settings path or {@code null} if none
-     */
-    @Nonnull
-    Optional<Path> getGlobalSettingsPath();
-
     /**
      * Gets the global settings source.
      *
@@ -64,22 +57,6 @@ public interface SettingsBuilderRequest {
     @Nonnull
     Optional<Source> getProjectSettingsSource();
 
-    /**
-     * Gets the project settings path.
-     *
-     * @return the project settings path or {@code null} if none
-     */
-    @Nonnull
-    Optional<Path> getProjectSettingsPath();
-
-    /**
-     * Gets the user settings path.
-     *
-     * @return the user settings path or {@code null} if none
-     */
-    @Nonnull
-    Optional<Path> getUserSettingsPath();
-
     /**
      * Gets the user settings source.
      *
@@ -97,34 +74,43 @@ public interface SettingsBuilderRequest {
     @Nonnull
     static SettingsBuilderRequest build(
             @Nonnull Session session, @Nonnull Path globalSettingsPath, @Nonnull Path userSettingsPath) {
-        return build(session, globalSettingsPath, null, userSettingsPath);
+        return build(session, Source.fromPath(globalSettingsPath), null, Source.fromPath(userSettingsPath));
     }
 
     @Nonnull
     static SettingsBuilderRequest build(
             @Nonnull Session session,
-            @Nonnull Source globalSettingsSource,
-            @Nonnull Source projectSettingsSource,
-            @Nonnull Source userSettingsSource) {
+            @Nullable Source globalSettingsSource,
+            @Nullable Source projectSettingsSource,
+            @Nullable Source userSettingsSource) {
         return builder()
                 .session(nonNull(session, "session cannot be null"))
-                .globalSettingsSource(nonNull(globalSettingsSource, "globalSettingsSource cannot be null"))
-                .projectSettingsSource(nonNull(projectSettingsSource, "projectSettingsSource cannot be null"))
-                .userSettingsSource(nonNull(userSettingsSource, "userSettingsSource cannot be null"))
+                .globalSettingsSource(globalSettingsSource)
+                .projectSettingsSource(projectSettingsSource)
+                .userSettingsSource(userSettingsSource)
                 .build();
     }
 
     @Nonnull
     static SettingsBuilderRequest build(
             @Nonnull Session session,
-            @Nonnull Path globalSettingsPath,
-            @Nonnull Path projectSettingsPath,
-            @Nonnull Path userSettingsPath) {
+            @Nullable Path globalSettingsPath,
+            @Nullable Path projectSettingsPath,
+            @Nullable Path userSettingsPath) {
         return builder()
                 .session(nonNull(session, "session cannot be null"))
-                .globalSettingsPath(nonNull(globalSettingsPath, "globalSettingsPath cannot be null"))
-                .projectSettingsPath(nonNull(projectSettingsPath, "projectSettingsPath cannot be null"))
-                .userSettingsPath(nonNull(userSettingsPath, "userSettingsPath cannot be null"))
+                .globalSettingsSource(
+                        globalSettingsPath != null && Files.exists(globalSettingsPath)
+                                ? Source.fromPath(globalSettingsPath)
+                                : null)
+                .projectSettingsSource(
+                        projectSettingsPath != null && Files.exists(projectSettingsPath)
+                                ? Source.fromPath(projectSettingsPath)
+                                : null)
+                .userSettingsSource(
+                        userSettingsPath != null && Files.exists(userSettingsPath)
+                                ? Source.fromPath(userSettingsPath)
+                                : null)
                 .build();
     }
 
@@ -136,11 +122,8 @@ public interface SettingsBuilderRequest {
     @NotThreadSafe
     class SettingsBuilderRequestBuilder {
         Session session;
-        Path globalSettingsPath;
         Source globalSettingsSource;
-        Path projectSettingsPath;
         Source projectSettingsSource;
-        Path userSettingsPath;
         Source userSettingsSource;
 
         public SettingsBuilderRequestBuilder session(Session session) {
@@ -148,31 +131,16 @@ public interface SettingsBuilderRequest {
             return this;
         }
 
-        public SettingsBuilderRequestBuilder globalSettingsPath(Path globalSettingsPath) {
-            this.globalSettingsPath = globalSettingsPath;
-            return this;
-        }
-
         public SettingsBuilderRequestBuilder globalSettingsSource(Source globalSettingsSource) {
             this.globalSettingsSource = globalSettingsSource;
             return this;
         }
 
-        public SettingsBuilderRequestBuilder projectSettingsPath(Path projectSettingsPath) {
-            this.projectSettingsPath = projectSettingsPath;
-            return this;
-        }
-
         public SettingsBuilderRequestBuilder projectSettingsSource(Source projectSettingsSource) {
             this.projectSettingsSource = projectSettingsSource;
             return this;
         }
 
-        public SettingsBuilderRequestBuilder userSettingsPath(Path userSettingsPath) {
-            this.userSettingsPath = userSettingsPath;
-            return this;
-        }
-
         public SettingsBuilderRequestBuilder userSettingsSource(Source userSettingsSource) {
             this.userSettingsSource = userSettingsSource;
             return this;
@@ -180,71 +148,38 @@ public interface SettingsBuilderRequest {
 
         public SettingsBuilderRequest build() {
             return new DefaultSettingsBuilderRequest(
-                    session,
-                    globalSettingsPath,
-                    globalSettingsSource,
-                    projectSettingsPath,
-                    projectSettingsSource,
-                    userSettingsPath,
-                    userSettingsSource);
+                    session, globalSettingsSource, projectSettingsSource, userSettingsSource);
         }
 
         private static class DefaultSettingsBuilderRequest extends BaseRequest implements SettingsBuilderRequest {
-            private final Path globalSettingsPath;
             private final Source globalSettingsSource;
-            private final Path projectSettingsPath;
             private final Source projectSettingsSource;
-            private final Path userSettingsPath;
             private final Source userSettingsSource;
 
             @SuppressWarnings("checkstyle:ParameterNumber")
             DefaultSettingsBuilderRequest(
                     @Nonnull Session session,
-                    @Nullable Path globalSettingsPath,
                     @Nullable Source globalSettingsSource,
-                    @Nullable Path projectSettingsPath,
                     @Nullable Source projectSettingsSource,
-                    @Nullable Path userSettingsPath,
                     @Nullable Source userSettingsSource) {
                 super(session);
-                this.globalSettingsPath = globalSettingsPath;
                 this.globalSettingsSource = globalSettingsSource;
-                this.projectSettingsPath = projectSettingsPath;
                 this.projectSettingsSource = projectSettingsSource;
-                this.userSettingsPath = userSettingsPath;
                 this.userSettingsSource = userSettingsSource;
             }
 
-            @Nonnull
-            @Override
-            public Optional<Path> getGlobalSettingsPath() {
-                return Optional.ofNullable(globalSettingsPath);
-            }
-
             @Nonnull
             @Override
             public Optional<Source> getGlobalSettingsSource() {
                 return Optional.ofNullable(globalSettingsSource);
             }
 
-            @Nonnull
-            @Override
-            public Optional<Path> getProjectSettingsPath() {
-                return Optional.ofNullable(projectSettingsPath);
-            }
-
             @Nonnull
             @Override
             public Optional<Source> getProjectSettingsSource() {
                 return Optional.ofNullable(projectSettingsSource);
             }
 
-            @Nonnull
-            @Override
-            public Optional<Path> getUserSettingsPath() {
-                return Optional.ofNullable(userSettingsPath);
-            }
-
             @Nonnull
             @Override
             public Optional<Source> getUserSettingsSource() {

api/maven-api-core/src/main/java/org/apache/maven/api/services/Source.java

@@ -27,6 +27,8 @@ import org.apache.maven.api.annotations.Experimental;
 import org.apache.maven.api.annotations.Nonnull;
 import org.apache.maven.api.annotations.Nullable;
 
+import static org.apache.maven.api.services.BaseRequest.nonNull;
+
 /**
  * Provides access to the contents of a source independently of the
  * backing store (e.g. file system, database, memory).
@@ -86,4 +88,12 @@ public interface Source {
      * @return related source or <code>null</code> if no such source
      */
     Source resolve(String relative);
+
+    /**
+     * Creates a Source for the following Path
+     */
+    @Nonnull
+    static Source fromPath(@Nonnull Path path) {
+        return new PathSource(nonNull(path, "path cannot be null"));
+    }
 }

api/maven-api-core/src/main/java/org/apache/maven/api/services/ToolchainsBuilderException.java

@@ -18,6 +18,9 @@
  */
 package org.apache.maven.api.services;
 
+import java.util.List;
+import java.util.stream.Collectors;
+
 import org.apache.maven.api.annotations.Experimental;
 
 /**
@@ -27,13 +30,24 @@ import org.apache.maven.api.annotations.Experimental;
  */
 @Experimental
 public class ToolchainsBuilderException extends MavenException {
+
+    private final List<BuilderProblem> problems;
+
     /**
      * @param message the message to give
      * @param e the {@link Exception}
      */
     public ToolchainsBuilderException(String message, Exception e) {
         super(message, e);
+        this.problems = List.of();
     }
 
-    // TODO: add ToolchainsBuilderResult
+    public ToolchainsBuilderException(String message, List<BuilderProblem> problems) {
+        super(message + ": " + problems.stream().map(BuilderProblem::toString).collect(Collectors.joining(", ")), null);
+        this.problems = List.copyOf(problems);
+    }
+
+    public List<BuilderProblem> getProblems() {
+        return problems;
+    }
 }

api/maven-api-core/src/main/java/org/apache/maven/api/services/ToolchainsBuilderRequest.java

@@ -18,6 +18,7 @@
  */
 package org.apache.maven.api.services;
 
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Optional;
 
@@ -38,14 +39,6 @@ public interface ToolchainsBuilderRequest {
     @Nonnull
     Session getSession();
 
-    /**
-     * Gets the global Toolchains path.
-     *
-     * @return the global Toolchains path or {@code null} if none
-     */
-    @Nonnull
-    Optional<Path> getGlobalToolchainsPath();
-
     /**
      * Gets the global Toolchains source.
      *
@@ -54,14 +47,6 @@ public interface ToolchainsBuilderRequest {
     @Nonnull
     Optional<Source> getGlobalToolchainsSource();
 
-    /**
-     * Gets the user Toolchains path.
-     *
-     * @return the user Toolchains path or {@code null} if none
-     */
-    @Nonnull
-    Optional<Path> getUserToolchainsPath();
-
     /**
      * Gets the user Toolchains source.
      *
@@ -72,21 +57,27 @@ public interface ToolchainsBuilderRequest {
 
     @Nonnull
     static ToolchainsBuilderRequest build(
-            @Nonnull Session session, @Nonnull Source globalToolchainsSource, @Nonnull Source userToolchainsSource) {
+            @Nonnull Session session, @Nullable Source globalToolchainsSource, @Nullable Source userToolchainsSource) {
         return builder()
                 .session(nonNull(session, "session cannot be null"))
-                .globalToolchainsSource(nonNull(globalToolchainsSource, "globalToolchainsSource cannot be null"))
-                .userToolchainsSource(nonNull(userToolchainsSource, "userToolchainsSource cannot be null"))
+                .globalToolchainsSource(globalToolchainsSource)
+                .userToolchainsSource(userToolchainsSource)
                 .build();
     }
 
     @Nonnull
     static ToolchainsBuilderRequest build(
-            @Nonnull Session session, @Nonnull Path globalToolchainsPath, @Nonnull Path userToolchainsPath) {
+            @Nonnull Session session, @Nullable Path globalToolchainsPath, @Nullable Path userToolchainsPath) {
         return builder()
                 .session(nonNull(session, "session cannot be null"))
-                .globalToolchainsPath(nonNull(globalToolchainsPath, "globalToolchainsPath cannot be null"))
-                .userToolchainsPath(nonNull(userToolchainsPath, "userToolchainsPath cannot be null"))
+                .globalToolchainsSource(
+                        globalToolchainsPath != null && Files.exists(globalToolchainsPath)
+                                ? Source.fromPath(globalToolchainsPath)
+                                : null)
+                .userToolchainsSource(
+                        userToolchainsPath != null && Files.exists(userToolchainsPath)
+                                ? Source.fromPath(userToolchainsPath)
+                                : null)
                 .build();
     }
 
@@ -98,9 +89,7 @@ public interface ToolchainsBuilderRequest {
     @NotThreadSafe
     class ToolchainsBuilderRequestBuilder {
         Session session;
-        Path globalToolchainsPath;
         Source globalToolchainsSource;
-        Path userToolchainsPath;
         Source userToolchainsSource;
 
         public ToolchainsBuilderRequestBuilder session(Session session) {
@@ -108,21 +97,11 @@ public interface ToolchainsBuilderRequest {
             return this;
         }
 
-        public ToolchainsBuilderRequestBuilder globalToolchainsPath(Path globalToolchainsPath) {
-            this.globalToolchainsPath = globalToolchainsPath;
-            return this;
-        }
-
         public ToolchainsBuilderRequestBuilder globalToolchainsSource(Source globalToolchainsSource) {
             this.globalToolchainsSource = globalToolchainsSource;
             return this;
         }
 
-        public ToolchainsBuilderRequestBuilder userToolchainsPath(Path userToolchainsPath) {
-            this.userToolchainsPath = userToolchainsPath;
-            return this;
-        }
-
         public ToolchainsBuilderRequestBuilder userToolchainsSource(Source userToolchainsSource) {
             this.userToolchainsSource = userToolchainsSource;
             return this;
@@ -130,47 +109,29 @@ public interface ToolchainsBuilderRequest {
 
         public ToolchainsBuilderRequest build() {
             return new ToolchainsBuilderRequestBuilder.DefaultToolchainsBuilderRequest(
-                    session, globalToolchainsPath, globalToolchainsSource, userToolchainsPath, userToolchainsSource);
+                    session, globalToolchainsSource, userToolchainsSource);
         }
 
         private static class DefaultToolchainsBuilderRequest extends BaseRequest implements ToolchainsBuilderRequest {
-            private final Path globalToolchainsPath;
             private final Source globalToolchainsSource;
-            private final Path userToolchainsPath;
             private final Source userToolchainsSource;
 
             @SuppressWarnings("checkstyle:ParameterNumber")
             DefaultToolchainsBuilderRequest(
                     @Nonnull Session session,
-                    @Nullable Path globalToolchainsPath,
                     @Nullable Source globalToolchainsSource,
-                    @Nullable Path userToolchainsPath,
                     @Nullable Source userToolchainsSource) {
                 super(session);
-                this.globalToolchainsPath = globalToolchainsPath;
                 this.globalToolchainsSource = globalToolchainsSource;
-                this.userToolchainsPath = userToolchainsPath;
                 this.userToolchainsSource = userToolchainsSource;
             }
 
-            @Nonnull
-            @Override
-            public Optional<Path> getGlobalToolchainsPath() {
-                return Optional.ofNullable(globalToolchainsPath);
-            }
-
             @Nonnull
             @Override
             public Optional<Source> getGlobalToolchainsSource() {
                 return Optional.ofNullable(globalToolchainsSource);
             }
 
-            @Nonnull
-            @Override
-            public Optional<Path> getUserToolchainsPath() {
-                return Optional.ofNullable(userToolchainsPath);
-            }
-
             @Nonnull
             @Override
             public Optional<Source> getUserToolchainsSource() {

api/maven-api-core/src/main/java/org/apache/maven/api/services/xml/Location.java

@@ -0,0 +1,58 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.api.services.xml;
+
+public interface Location {
+
+    /**
+     * Return the line number where the current event ends,
+     * returns -1 if none is available.
+     * @return the current line number
+     */
+    int getLineNumber();
+
+    /**
+     * Return the column number where the current event ends,
+     * returns -1 if none is available.
+     * @return the current column number
+     */
+    int getColumnNumber();
+
+    /**
+     * Return the byte or character offset into the input source this location
+     * is pointing to. If the input source is a file or a byte stream then
+     * this is the byte offset into that stream, but if the input source is
+     * a character media then the offset is the character offset.
+     * Returns -1 if there is no offset available.
+     * @return the current offset
+     */
+    int getCharacterOffset();
+
+    /**
+     * Returns the public ID of the XML
+     * @return the public ID, or null if not available
+     */
+    String getPublicId();
+
+    /**
+     * Returns the system ID of the XML
+     * @return the system ID, or null if not available
+     */
+    String getSystemId();
+}

api/maven-api-core/src/main/java/org/apache/maven/api/services/xml/XmlReaderException.java

@@ -29,11 +29,18 @@ import org.apache.maven.api.services.MavenException;
 @Experimental
 public class XmlReaderException extends MavenException {
 
+    private final Location location;
+
     /**
      * @param message the message for the exception
      * @param e the exception itself
      */
-    public XmlReaderException(String message, Exception e) {
+    public XmlReaderException(String message, Location location, Exception e) {
         super(message, e);
+        this.location = location;
+    }
+
+    public Location getLocation() {
+        return location;
     }
 }

api/maven-api-core/src/main/java/org/apache/maven/api/services/xml/XmlWriterException.java

@@ -29,11 +29,18 @@ import org.apache.maven.api.services.MavenException;
 @Experimental
 public class XmlWriterException extends MavenException {
 
+    private final Location location;
+
     /**
      * @param message the message for the exception
      * @param e the exception itself
      */
-    public XmlWriterException(String message, Exception e) {
+    public XmlWriterException(String message, Location location, Exception e) {
         super(message, e);
+        this.location = location;
+    }
+
+    public Location getLocation() {
+        return location;
     }
 }

maven-api-impl/pom.xml

@@ -0,0 +1,140 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.apache.maven</groupId>
+    <artifactId>maven</artifactId>
+    <version>4.0.0-alpha-14-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>maven-api-impl</artifactId>
+  <name>Maven API Implementation</name>
+  <description>Provides the implementation classes for the Maven API</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-di</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven.resolver</groupId>
+      <artifactId>maven-resolver-api</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven.resolver</groupId>
+      <artifactId>maven-resolver-spi</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven.resolver</groupId>
+      <artifactId>maven-resolver-util</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven.resolver</groupId>
+      <artifactId>maven-resolver-supplier</artifactId>
+      <version>${resolverVersion}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-resolver-provider</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.modello</groupId>
+        <artifactId>modello-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>velocity-settings</id>
+            <goals>
+              <goal>velocity</goal>
+            </goals>
+            <phase>generate-sources</phase>
+            <configuration>
+              <version>2.0.0</version>
+              <basedir>${project.basedir}/../api/maven-api-settings</basedir>
+              <velocityBasedir>${project.basedir}/../src/mdo</velocityBasedir>
+              <models>
+                <model>src/main/mdo/settings.mdo</model>
+              </models>
+              <templates>
+                <template>merger.vm</template>
+                <template>transformer.vm</template>
+                <template>reader-stax.vm</template>
+                <template>writer-stax.vm</template>
+              </templates>
+              <params>
+                <param>forcedIOModelVersion=1.2.0</param>
+                <param>packageModelV3=org.apache.maven.settings</param>
+                <param>packageModelV4=org.apache.maven.api.settings</param>
+                <param>packageToolV4=org.apache.maven.settings.v4</param>
+                <param>locationTracking=true</param>
+                <param>generateLocationClasses=true</param>
+              </params>
+            </configuration>
+          </execution>
+          <execution>
+            <id>velocity-toolchains</id>
+            <goals>
+              <goal>velocity</goal>
+            </goals>
+            <phase>generate-sources</phase>
+            <configuration>
+              <version>1.1.0</version>
+              <basedir>${project.basedir}/../api/maven-api-toolchain</basedir>
+              <velocityBasedir>${project.basedir}/../src/mdo</velocityBasedir>
+              <models>
+                <model>src/main/mdo/toolchains.mdo</model>
+              </models>
+              <templates>
+                <template>merger.vm</template>
+                <template>transformer.vm</template>
+                <template>reader-stax.vm</template>
+                <template>writer-stax.vm</template>
+              </templates>
+              <params>
+                <param>packageModelV3=org.apache.maven.toolchain.model</param>
+                <param>packageModelV4=org.apache.maven.api.toolchain</param>
+                <param>packageToolV4=org.apache.maven.toolchain.v4</param>
+              </params>
+            </configuration>
+          </execution>
+          <execution>
+            <id>modello-site-docs</id>
+            <phase>none</phase>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>

maven-api-impl/src/main/java/org/apache/maven/internal/impl/AbstractSession.java

@@ -25,24 +25,55 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.WeakHashMap;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
-import org.apache.maven.api.*;
+import org.apache.maven.api.Artifact;
+import org.apache.maven.api.ArtifactCoordinate;
+import org.apache.maven.api.Dependency;
+import org.apache.maven.api.DependencyCoordinate;
+import org.apache.maven.api.DependencyScope;
+import org.apache.maven.api.Language;
+import org.apache.maven.api.Listener;
+import org.apache.maven.api.LocalRepository;
+import org.apache.maven.api.Node;
+import org.apache.maven.api.Packaging;
+import org.apache.maven.api.PathScope;
+import org.apache.maven.api.PathType;
+import org.apache.maven.api.Project;
+import org.apache.maven.api.ProjectScope;
+import org.apache.maven.api.RemoteRepository;
+import org.apache.maven.api.Service;
+import org.apache.maven.api.Session;
+import org.apache.maven.api.SessionData;
+import org.apache.maven.api.Type;
+import org.apache.maven.api.Version;
+import org.apache.maven.api.VersionConstraint;
+import org.apache.maven.api.VersionRange;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.annotations.Nullable;
 import org.apache.maven.api.model.Repository;
 import org.apache.maven.api.services.*;
-import org.apache.maven.artifact.repository.ArtifactRepository;
-import org.apache.maven.project.MavenProject;
+import org.eclipse.aether.DefaultRepositorySystemSession;
+import org.eclipse.aether.RepositorySystem;
+import org.eclipse.aether.RepositorySystemSession;
 
 import static org.apache.maven.internal.impl.Utils.map;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 public abstract class AbstractSession implements InternalSession {
 
+    protected final RepositorySystemSession session;
+    protected final RepositorySystem repositorySystem;
+    protected final List<RemoteRepository> repositories;
+    protected final Lookup lookup;
+    private final Map<Class<? extends Service>, Service> services = new ConcurrentHashMap<>();
     private final List<Listener> listeners = new CopyOnWriteArrayList<>();
     private final Map<org.eclipse.aether.graph.DependencyNode, Node> allNodes =
             Collections.synchronizedMap(new WeakHashMap<>());
@@ -50,10 +81,21 @@ public abstract class AbstractSession implements InternalSession {
             Collections.synchronizedMap(new WeakHashMap<>());
     private final Map<org.eclipse.aether.repository.RemoteRepository, RemoteRepository> allRepositories =
             Collections.synchronizedMap(new WeakHashMap<>());
-    private final Map<String, Project> allProjects = Collections.synchronizedMap(new WeakHashMap<>());
     private final Map<org.eclipse.aether.graph.Dependency, Dependency> allDependencies =
             Collections.synchronizedMap(new WeakHashMap<>());
 
+    public AbstractSession(
+            RepositorySystemSession session,
+            RepositorySystem repositorySystem,
+            List<RemoteRepository> repositories,
+            List<org.eclipse.aether.repository.RemoteRepository> resolverRepositories,
+            Lookup lookup) {
+        this.session = session;
+        this.repositorySystem = repositorySystem;
+        this.repositories = getRepositories(repositories, resolverRepositories);
+        this.lookup = lookup;
+    }
+
     @Override
     public RemoteRepository getRemoteRepository(org.eclipse.aether.repository.RemoteRepository repository) {
         return allRepositories.computeIfAbsent(repository, DefaultRemoteRepository::new);
@@ -81,16 +123,6 @@ public abstract class AbstractSession implements InternalSession {
         return allDependencies.computeIfAbsent(dependency, d -> new DefaultDependency(this, d));
     }
 
-    @Override
-    public List<Project> getProjects(List<MavenProject> projects) {
-        return projects == null ? null : map(projects, this::getProject);
-    }
-
-    @Override
-    public Project getProject(MavenProject project) {
-        return allProjects.computeIfAbsent(project.getId(), id -> new DefaultProject(this, project));
-    }
-
     @Override
     public List<org.eclipse.aether.repository.RemoteRepository> toRepositories(List<RemoteRepository> repositories) {
         return repositories == null ? null : map(repositories, this::toRepository);
@@ -116,22 +148,143 @@ public abstract class AbstractSession implements InternalSession {
         }
     }
 
-    @Override
-    public List<ArtifactRepository> toArtifactRepositories(List<RemoteRepository> repositories) {
-        return repositories == null ? null : map(repositories, this::toArtifactRepository);
-    }
-
-    @Override
-    public abstract ArtifactRepository toArtifactRepository(RemoteRepository repository);
-
     @Override
     public List<org.eclipse.aether.graph.Dependency> toDependencies(
             Collection<DependencyCoordinate> dependencies, boolean managed) {
         return dependencies == null ? null : map(dependencies, d -> toDependency(d, managed));
     }
 
+    protected List<RemoteRepository> getRepositories(
+            List<RemoteRepository> repositories,
+            List<org.eclipse.aether.repository.RemoteRepository> resolverRepositories) {
+        if (repositories != null) {
+            return repositories;
+        } else if (resolverRepositories != null) {
+            return map(resolverRepositories, this::getRemoteRepository);
+        } else {
+            throw new IllegalArgumentException("no remote repositories provided");
+        }
+    }
+
+    @Nonnull
     @Override
-    public abstract org.eclipse.aether.graph.Dependency toDependency(DependencyCoordinate dependency, boolean managed);
+    public List<RemoteRepository> getRemoteRepositories() {
+        return Collections.unmodifiableList(repositories);
+    }
+
+    @Nonnull
+    @Override
+    public SessionData getData() {
+        org.eclipse.aether.SessionData data = session.getData();
+        return new SessionData() {
+            @Override
+            public <T> void set(@Nonnull Key<T> key, @Nullable T value) {
+                data.set(key, value);
+            }
+
+            @Override
+            public <T> boolean replace(@Nonnull Key<T> key, @Nullable T oldValue, @Nullable T newValue) {
+                return data.set(key, oldValue, newValue);
+            }
+
+            @Nullable
+            @Override
+            @SuppressWarnings("unchecked")
+            public <T> T get(@Nonnull Key<T> key) {
+                return (T) data.get(key);
+            }
+
+            @Nullable
+            @Override
+            @SuppressWarnings("unchecked")
+            public <T> T computeIfAbsent(@Nonnull Key<T> key, @Nonnull Supplier<T> supplier) {
+                return (T) data.computeIfAbsent(key, (Supplier<Object>) supplier);
+            }
+        };
+    }
+
+    @Nonnull
+    @Override
+    public LocalRepository getLocalRepository() {
+        return new DefaultLocalRepository(session.getLocalRepository());
+    }
+
+    @Nonnull
+    @Override
+    public Session withLocalRepository(@Nonnull LocalRepository localRepository) {
+        nonNull(localRepository, "localRepository");
+        if (session.getLocalRepository() != null
+                && Objects.equals(session.getLocalRepository().getBasedir().toPath(), localRepository.getPath())) {
+            return this;
+        }
+        org.eclipse.aether.repository.LocalRepository repository = toRepository(localRepository);
+        org.eclipse.aether.repository.LocalRepositoryManager localRepositoryManager =
+                repositorySystem.newLocalRepositoryManager(session, repository);
+
+        RepositorySystemSession repoSession =
+                new DefaultRepositorySystemSession(session).setLocalRepositoryManager(localRepositoryManager);
+        return newSession(repoSession, repositories);
+    }
+
+    @Nonnull
+    @Override
+    public Session withRemoteRepositories(@Nonnull List<RemoteRepository> repositories) {
+        return newSession(session, repositories);
+    }
+
+    protected abstract Session newSession(RepositorySystemSession session, List<RemoteRepository> repositories);
+
+    @Nonnull
+    @Override
+    @SuppressWarnings("unchecked")
+    public <T extends Service> T getService(Class<T> clazz) throws NoSuchElementException {
+        T t = (T) services.computeIfAbsent(clazz, this::lookup);
+        if (t == null) {
+            throw new NoSuchElementException(clazz.getName());
+        }
+        return t;
+    }
+
+    private Service lookup(Class<? extends Service> c) {
+        try {
+            return lookup.lookup(c);
+        } catch (LookupException e) {
+            NoSuchElementException nsee = new NoSuchElementException(c.getName());
+            e.initCause(e);
+            throw nsee;
+        }
+    }
+
+    @Nonnull
+    public RepositorySystemSession getSession() {
+        return session;
+    }
+
+    @Nonnull
+    public RepositorySystem getRepositorySystem() {
+        return repositorySystem;
+    }
+
+    public org.eclipse.aether.graph.Dependency toDependency(DependencyCoordinate dependency, boolean managed) {
+        org.eclipse.aether.graph.Dependency dep;
+        if (dependency instanceof DefaultDependencyCoordinate) {
+            dep = ((DefaultDependencyCoordinate) dependency).getDependency();
+        } else {
+            dep = new org.eclipse.aether.graph.Dependency(
+                    new org.eclipse.aether.artifact.DefaultArtifact(
+                            dependency.getGroupId(),
+                            dependency.getArtifactId(),
+                            dependency.getClassifier(),
+                            dependency.getType().getExtension(),
+                            dependency.getVersion().toString(),
+                            null),
+                    dependency.getScope().id());
+        }
+        if (!managed && "".equals(dep.getScope())) {
+            dep = dep.setScope(DependencyScope.COMPILE.id());
+        }
+        return dep;
+    }
 
     @Override
     public List<org.eclipse.aether.artifact.Artifact> toArtifacts(Collection<Artifact> artifacts) {

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultArtifactCoordinateFactory.java

@@ -18,11 +18,10 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import org.apache.maven.api.ArtifactCoordinate;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.ArtifactCoordinateFactory;
 import org.apache.maven.api.services.ArtifactCoordinateFactoryRequest;
 import org.eclipse.aether.artifact.ArtifactType;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultArtifactDeployer.java

@@ -18,14 +18,13 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.util.Collection;
 
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.RemoteRepository;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.ArtifactDeployer;
 import org.apache.maven.api.services.ArtifactDeployerException;
 import org.apache.maven.api.services.ArtifactDeployerRequest;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultArtifactFactory.java

@@ -18,11 +18,10 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.ArtifactFactory;
 import org.apache.maven.api.services.ArtifactFactoryRequest;
 import org.eclipse.aether.artifact.ArtifactType;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultArtifactInstaller.java

@@ -18,11 +18,10 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.ArtifactInstaller;
 import org.apache.maven.api.services.ArtifactInstallerException;
 import org.apache.maven.api.services.ArtifactInstallerRequest;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultArtifactResolver.java

@@ -18,9 +18,6 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -29,6 +26,8 @@ import java.util.Map;
 
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.ArtifactCoordinate;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.ArtifactManager;
 import org.apache.maven.api.services.ArtifactResolver;
 import org.apache.maven.api.services.ArtifactResolverException;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultBuilderProblem.java

@@ -0,0 +1,111 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import org.apache.maven.api.services.BuilderProblem;
+
+/**
+ * Describes a problem that was encountered during settings building. A problem can either be an exception that was
+ * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
+ * that exhibits the problem.
+ */
+class DefaultBuilderProblem implements BuilderProblem {
+    final String source;
+    final int lineNumber;
+    final int columnNumber;
+    final Exception exception;
+    final String message;
+    final Severity severity;
+
+    DefaultBuilderProblem(
+            String source, int lineNumber, int columnNumber, Exception exception, String message, Severity severity) {
+        this.source = source;
+        this.lineNumber = lineNumber;
+        this.columnNumber = columnNumber;
+        this.exception = exception;
+        this.message = message;
+        this.severity = severity;
+    }
+
+    @Override
+    public String getSource() {
+        return source;
+    }
+
+    @Override
+    public int getLineNumber() {
+        return lineNumber;
+    }
+
+    @Override
+    public int getColumnNumber() {
+        return columnNumber;
+    }
+
+    @Override
+    public Exception getException() {
+        return exception;
+    }
+
+    @Override
+    public String getMessage() {
+        return message;
+    }
+
+    @Override
+    public Severity getSeverity() {
+        return severity;
+    }
+
+    @Override
+    public String getLocation() {
+        StringBuilder buffer = new StringBuilder(256);
+        if (!getSource().isEmpty()) {
+            buffer.append(getSource());
+        }
+        if (getLineNumber() > 0) {
+            if (!buffer.isEmpty()) {
+                buffer.append(", ");
+            }
+            buffer.append("line ").append(getLineNumber());
+        }
+        if (getColumnNumber() > 0) {
+            if (!buffer.isEmpty()) {
+                buffer.append(", ");
+            }
+            buffer.append("column ").append(getColumnNumber());
+        }
+        return buffer.toString();
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder buffer = new StringBuilder(128);
+        buffer.append('[').append(severity).append("]");
+        String msg = message != null ? message : exception != null ? exception.getMessage() : null;
+        if (msg != null && !msg.isEmpty()) {
+            buffer.append(" ").append(msg);
+        }
+        String location = getLocation();
+        if (!location.isEmpty()) {
+            buffer.append(" @ ").append(location);
+        }
+        return buffer.toString();
+    }
+}

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultChecksumAlgorithmService.java

@@ -18,18 +18,26 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
-import java.io.*;
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
 import java.nio.ByteBuffer;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
-import org.apache.maven.api.services.*;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
+import org.apache.maven.api.services.ChecksumAlgorithmService;
+import org.apache.maven.api.services.ChecksumAlgorithmServiceException;
 import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactory;
 import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactorySelector;
 

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultDependencyCollector.java

@@ -18,15 +18,22 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.util.Collection;
 import java.util.List;
 
-import org.apache.maven.api.*;
+import org.apache.maven.api.Artifact;
+import org.apache.maven.api.DependencyCoordinate;
+import org.apache.maven.api.Node;
+import org.apache.maven.api.Project;
+import org.apache.maven.api.RemoteRepository;
 import org.apache.maven.api.annotations.Nonnull;
-import org.apache.maven.api.services.*;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
+import org.apache.maven.api.services.DependencyCollector;
+import org.apache.maven.api.services.DependencyCollectorException;
+import org.apache.maven.api.services.DependencyCollectorRequest;
+import org.apache.maven.api.services.DependencyCollectorResult;
+import org.apache.maven.api.services.ProjectManager;
 import org.eclipse.aether.DefaultRepositorySystemSession;
 import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.collection.CollectRequest;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultDependencyCoordinate.java

@@ -20,7 +20,11 @@ package org.apache.maven.internal.impl;
 
 import java.util.Collection;
 
-import org.apache.maven.api.*;
+import org.apache.maven.api.DependencyCoordinate;
+import org.apache.maven.api.DependencyScope;
+import org.apache.maven.api.Exclusion;
+import org.apache.maven.api.Type;
+import org.apache.maven.api.VersionConstraint;
 import org.apache.maven.api.annotations.Nonnull;
 import org.apache.maven.api.annotations.Nullable;
 import org.eclipse.aether.artifact.ArtifactProperties;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultDependencyCoordinateFactory.java

@@ -18,12 +18,11 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import org.apache.maven.api.DependencyCoordinate;
 import org.apache.maven.api.Exclusion;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.DependencyCoordinateFactory;
 import org.apache.maven.api.services.DependencyCoordinateFactoryRequest;
 import org.eclipse.aether.artifact.ArtifactType;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultLocalRepository.java

@@ -18,8 +18,6 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-
 import java.nio.file.Path;
 
 import org.apache.maven.api.LocalRepository;
@@ -31,7 +29,6 @@ public class DefaultLocalRepository implements LocalRepository {
 
     private final @Nonnull org.eclipse.aether.repository.LocalRepository repository;
 
-    @Inject
     public DefaultLocalRepository(@Nonnull org.eclipse.aether.repository.LocalRepository repository) {
         this.repository = nonNull(repository, "repository");
     }

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultLocalRepositoryManager.java

@@ -18,15 +18,14 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.nio.file.Path;
 
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.LocalRepository;
 import org.apache.maven.api.RemoteRepository;
 import org.apache.maven.api.Session;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.LocalRepositoryManager;
 
 @Named

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultMessageBuilderFactory.java

@@ -18,15 +18,14 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import org.apache.maven.api.annotations.Experimental;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Priority;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.MessageBuilder;
 import org.apache.maven.api.services.MessageBuilderFactory;
-import org.eclipse.sisu.Priority;
 
 @Experimental
 @Named

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultModelXmlFactory.java

@@ -18,9 +18,6 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.Reader;
@@ -30,6 +27,8 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.model.InputSource;
 import org.apache.maven.api.model.Model;
 import org.apache.maven.api.services.xml.ModelXmlFactory;
@@ -40,6 +39,8 @@ import org.apache.maven.api.services.xml.XmlWriterRequest;
 import org.apache.maven.model.v4.MavenStaxReader;
 import org.apache.maven.model.v4.MavenStaxWriter;
 
+import static org.apache.maven.internal.impl.StaxLocation.getLocation;
+import static org.apache.maven.internal.impl.StaxLocation.getMessage;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -76,7 +77,7 @@ public class DefaultModelXmlFactory implements ModelXmlFactory {
                 }
             }
         } catch (Exception e) {
-            throw new XmlReaderException("Unable to read model", e);
+            throw new XmlReaderException("Unable to read model: " + getMessage(e), getLocation(e), e);
         }
     }
 
@@ -101,7 +102,7 @@ public class DefaultModelXmlFactory implements ModelXmlFactory {
                 }
             }
         } catch (Exception e) {
-            throw new XmlWriterException("Unable to write model", e);
+            throw new XmlWriterException("Unable to write model: " + getMessage(e), getLocation(e), e);
         }
     }
 

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultRepositoryFactory.java

@@ -18,30 +18,20 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.nio.file.Path;
 
 import org.apache.maven.api.LocalRepository;
 import org.apache.maven.api.RemoteRepository;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.model.Repository;
 import org.apache.maven.api.services.RepositoryFactory;
-import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.repository.RepositoryPolicy;
 
 @Named
 @Singleton
 public class DefaultRepositoryFactory implements RepositoryFactory {
 
-    private final RepositorySystem repositorySystem;
-
-    @Inject
-    public DefaultRepositoryFactory(RepositorySystem repositorySystem) {
-        this.repositorySystem = repositorySystem;
-    }
-
     @Override
     public LocalRepository createLocal(Path path) {
         return new DefaultLocalRepository(new org.eclipse.aether.repository.LocalRepository(path.toFile()));

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultSettingsBuilder.java

@@ -0,0 +1,300 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import javax.xml.stream.Location;
+import javax.xml.stream.XMLStreamException;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.services.SettingsBuilder;
+import org.apache.maven.api.services.SettingsBuilderException;
+import org.apache.maven.api.services.SettingsBuilderRequest;
+import org.apache.maven.api.services.SettingsBuilderResult;
+import org.apache.maven.api.services.Source;
+import org.apache.maven.api.services.xml.SettingsXmlFactory;
+import org.apache.maven.api.services.xml.XmlReaderException;
+import org.apache.maven.api.services.xml.XmlReaderRequest;
+import org.apache.maven.api.settings.Profile;
+import org.apache.maven.api.settings.Repository;
+import org.apache.maven.api.settings.RepositoryPolicy;
+import org.apache.maven.api.settings.Server;
+import org.apache.maven.api.settings.Settings;
+import org.apache.maven.settings.v4.SettingsMerger;
+import org.apache.maven.settings.v4.SettingsTransformer;
+import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
+import org.codehaus.plexus.interpolation.InterpolationException;
+import org.codehaus.plexus.interpolation.MapBasedValueSource;
+import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
+
+/**
+ * Builds the effective settings from a user settings file and/or a global settings file.
+ *
+ */
+@Named
+public class DefaultSettingsBuilder implements SettingsBuilder {
+
+    private final DefaultSettingsValidator settingsValidator = new DefaultSettingsValidator();
+
+    private final SettingsMerger settingsMerger = new SettingsMerger();
+
+    @Override
+    public SettingsBuilderResult build(SettingsBuilderRequest request) throws SettingsBuilderException {
+        List<BuilderProblem> problems = new ArrayList<>();
+
+        Source globalSource = request.getGlobalSettingsSource().orElse(null);
+        Settings global = readSettings(globalSource, false, request, problems);
+
+        Source projectSource = request.getProjectSettingsSource().orElse(null);
+        Settings project = readSettings(projectSource, true, request, problems);
+
+        Source userSource = request.getUserSettingsSource().orElse(null);
+        Settings user = readSettings(userSource, false, request, problems);
+
+        Settings effective =
+                settingsMerger.merge(user, settingsMerger.merge(project, global, false, null), false, null);
+
+        // If no repository is defined in the user/global settings,
+        // it means that we have "old" settings (as those are new in 4.0)
+        // so add central to the computed settings for backward compatibility.
+        if (effective.getRepositories().isEmpty()
+                && effective.getPluginRepositories().isEmpty()) {
+            Repository central = Repository.newBuilder()
+                    .id("central")
+                    .name("Central Repository")
+                    .url("https://repo.maven.apache.org/maven2")
+                    .snapshots(RepositoryPolicy.newBuilder().enabled(false).build())
+                    .build();
+            Repository centralWithNoUpdate = central.withReleases(
+                    RepositoryPolicy.newBuilder().updatePolicy("never").build());
+            effective = Settings.newBuilder(effective)
+                    .repositories(List.of(central))
+                    .pluginRepositories(List.of(centralWithNoUpdate))
+                    .build();
+        }
+
+        // for the special case of a drive-relative Windows path, make sure it's absolute to save plugins from trouble
+        String localRepository = effective.getLocalRepository();
+        if (localRepository != null && !localRepository.isEmpty()) {
+            Path file = Paths.get(localRepository);
+            if (!file.isAbsolute() && file.toString().startsWith(File.separator)) {
+                effective = effective.withLocalRepository(file.toAbsolutePath().toString());
+            }
+        }
+
+        if (hasErrors(problems)) {
+            throw new SettingsBuilderException("Error building settings", problems);
+        }
+
+        return new DefaultSettingsBuilderResult(effective, problems);
+    }
+
+    private boolean hasErrors(List<BuilderProblem> problems) {
+        if (problems != null) {
+            for (BuilderProblem problem : problems) {
+                if (BuilderProblem.Severity.ERROR.compareTo(problem.getSeverity()) >= 0) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    private Settings readSettings(
+            Source settingsSource,
+            boolean isProjectSettings,
+            SettingsBuilderRequest request,
+            List<BuilderProblem> problems) {
+        if (settingsSource == null) {
+            return Settings.newInstance();
+        }
+
+        Settings settings;
+
+        try {
+            try {
+                InputStream is = settingsSource.openStream();
+                if (is == null) {
+                    return Settings.newInstance();
+                }
+                settings = request.getSession()
+                        .getService(SettingsXmlFactory.class)
+                        .read(XmlReaderRequest.builder()
+                                .inputStream(is)
+                                .location(settingsSource.getLocation())
+                                .strict(true)
+                                .build());
+            } catch (XmlReaderException e) {
+                InputStream is = settingsSource.openStream();
+                if (is == null) {
+                    return Settings.newInstance();
+                }
+                settings = request.getSession()
+                        .getService(SettingsXmlFactory.class)
+                        .read(XmlReaderRequest.builder()
+                                .inputStream(is)
+                                .location(settingsSource.getLocation())
+                                .strict(false)
+                                .build());
+                Location loc = e.getCause() instanceof XMLStreamException xe ? xe.getLocation() : null;
+                problems.add(new DefaultBuilderProblem(
+                        settingsSource.getLocation(),
+                        loc != null ? loc.getLineNumber() : -1,
+                        loc != null ? loc.getColumnNumber() : -1,
+                        e,
+                        e.getMessage(),
+                        BuilderProblem.Severity.WARNING));
+            }
+        } catch (XmlReaderException e) {
+            Location loc = e.getCause() instanceof XMLStreamException xe ? xe.getLocation() : null;
+            problems.add(new DefaultBuilderProblem(
+                    settingsSource.getLocation(),
+                    loc != null ? loc.getLineNumber() : -1,
+                    loc != null ? loc.getColumnNumber() : -1,
+                    e,
+                    "Non-parseable settings " + settingsSource.getLocation() + ": " + e.getMessage(),
+                    BuilderProblem.Severity.FATAL));
+            return Settings.newInstance();
+        } catch (IOException e) {
+            problems.add(new DefaultBuilderProblem(
+                    settingsSource.getLocation(),
+                    -1,
+                    -1,
+                    e,
+                    "Non-readable settings " + settingsSource.getLocation() + ": " + e.getMessage(),
+                    BuilderProblem.Severity.FATAL));
+            return Settings.newInstance();
+        }
+
+        settings = interpolate(settings, request, problems);
+
+        settingsValidator.validate(settings, isProjectSettings, problems);
+
+        if (isProjectSettings) {
+            settings = Settings.newBuilder(settings, true)
+                    .localRepository(null)
+                    .interactiveMode(false)
+                    .offline(false)
+                    .proxies(List.of())
+                    .usePluginRegistry(false)
+                    .servers(settings.getServers().stream()
+                            .map(s -> Server.newBuilder(s, true)
+                                    .username(null)
+                                    .passphrase(null)
+                                    .privateKey(null)
+                                    .password(null)
+                                    .filePermissions(null)
+                                    .directoryPermissions(null)
+                                    .build())
+                            .toList())
+                    .build();
+        }
+
+        return settings;
+    }
+
+    private Settings interpolate(Settings settings, SettingsBuilderRequest request, List<BuilderProblem> problems) {
+
+        RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
+
+        interpolator.addValueSource(new MapBasedValueSource(request.getSession().getUserProperties()));
+
+        interpolator.addValueSource(new MapBasedValueSource(request.getSession().getSystemProperties()));
+
+        try {
+            interpolator.addValueSource(new EnvarBasedValueSource());
+        } catch (IOException e) {
+            problems.add(new DefaultBuilderProblem(
+                    null,
+                    -1,
+                    -1,
+                    e,
+                    "Failed to use environment variables for interpolation: " + e.getMessage(),
+                    BuilderProblem.Severity.WARNING));
+        }
+
+        return new SettingsTransformer(value -> {
+                    try {
+                        return value != null ? interpolator.interpolate(value) : null;
+                    } catch (InterpolationException e) {
+                        problems.add(new DefaultBuilderProblem(
+                                null,
+                                -1,
+                                -1,
+                                e,
+                                "Failed to interpolate settings: " + e.getMessage(),
+                                BuilderProblem.Severity.WARNING));
+                        return value;
+                    }
+                })
+                .visit(settings);
+    }
+
+    @Override
+    public List<BuilderProblem> validate(Settings settings, boolean isProjectSettings) {
+        ArrayList<BuilderProblem> problems = new ArrayList<>();
+        settingsValidator.validate(settings, isProjectSettings, problems);
+        return problems;
+    }
+
+    @Override
+    public Profile convert(org.apache.maven.api.model.Profile profile) {
+        return SettingsUtilsV4.convertToSettingsProfile(profile);
+    }
+
+    @Override
+    public org.apache.maven.api.model.Profile convert(Profile profile) {
+        return SettingsUtilsV4.convertFromSettingsProfile(profile);
+    }
+
+    /**
+     * Collects the output of the settings builder.
+     *
+     */
+    static class DefaultSettingsBuilderResult implements SettingsBuilderResult {
+
+        private final Settings effectiveSettings;
+
+        private final List<BuilderProblem> problems;
+
+        DefaultSettingsBuilderResult(Settings effectiveSettings, List<BuilderProblem> problems) {
+            this.effectiveSettings = effectiveSettings;
+            this.problems = (problems != null) ? problems : new ArrayList<>();
+        }
+
+        @Override
+        public Settings getEffectiveSettings() {
+            return effectiveSettings;
+        }
+
+        @Override
+        public List<BuilderProblem> getProblems() {
+            return problems;
+        }
+    }
+}

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultSettingsValidator.java

@@ -0,0 +1,362 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.settings.Mirror;
+import org.apache.maven.api.settings.Profile;
+import org.apache.maven.api.settings.Proxy;
+import org.apache.maven.api.settings.Repository;
+import org.apache.maven.api.settings.Server;
+import org.apache.maven.api.settings.Settings;
+
+/**
+ */
+public class DefaultSettingsValidator {
+
+    private static final String ID = "[\\w.-]+";
+    private static final Pattern ID_REGEX = Pattern.compile(ID);
+
+    private static final String ILLEGAL_REPO_ID_CHARS = "\\/:\"<>|?*"; // ILLEGAL_FS_CHARS
+
+    public void validate(Settings settings, boolean isProjectSettings, List<BuilderProblem> problems) {
+        if (isProjectSettings) {
+            String msgS = "is not supported on project settings.";
+            String msgP = "are not supported on project settings.";
+            if (settings.getLocalRepository() != null
+                    && !settings.getLocalRepository().isEmpty()) {
+                addViolation(problems, BuilderProblem.Severity.WARNING, "localRepository", null, msgS);
+            }
+            if (!settings.isInteractiveMode()) {
+                addViolation(problems, BuilderProblem.Severity.WARNING, "interactiveMode", null, msgS);
+            }
+            if (settings.isOffline()) {
+                addViolation(problems, BuilderProblem.Severity.WARNING, "offline", null, msgS);
+            }
+            if (!settings.getProxies().isEmpty()) {
+                addViolation(problems, BuilderProblem.Severity.WARNING, "proxies", null, msgP);
+            }
+            if (settings.isUsePluginRegistry()) {
+                addViolation(problems, BuilderProblem.Severity.WARNING, "usePluginRegistry", null, msgS);
+            }
+            List<Server> servers = settings.getServers();
+            for (int i = 0; i < servers.size(); i++) {
+                Server server = servers.get(i);
+                String serverField = "servers.server[" + i + "]";
+                validateStringEmpty(problems, serverField + ".username", server.getUsername(), msgS);
+                validateStringEmpty(problems, serverField + ".password", server.getPassword(), msgS);
+                validateStringEmpty(problems, serverField + ".privateKey", server.getPrivateKey(), msgS);
+                validateStringEmpty(problems, serverField + ".passphrase", server.getPassphrase(), msgS);
+                validateStringEmpty(problems, serverField + ".filePermissions", server.getFilePermissions(), msgS);
+                validateStringEmpty(
+                        problems, serverField + ".directoryPermissions", server.getDirectoryPermissions(), msgS);
+            }
+        }
+
+        if (settings.isUsePluginRegistry()) {
+            addViolation(
+                    problems,
+                    BuilderProblem.Severity.WARNING,
+                    "usePluginRegistry",
+                    null,
+                    "is deprecated and has no effect.");
+        }
+
+        List<String> pluginGroups = settings.getPluginGroups();
+
+        if (pluginGroups != null) {
+            for (int i = 0; i < pluginGroups.size(); i++) {
+                String pluginGroup = pluginGroups.get(i);
+
+                validateStringNotEmpty(problems, "pluginGroups.pluginGroup[" + i + "]", pluginGroup, null);
+
+                if (!ID_REGEX.matcher(pluginGroup).matches()) {
+                    addViolation(
+                            problems,
+                            BuilderProblem.Severity.ERROR,
+                            "pluginGroups.pluginGroup[" + i + "]",
+                            null,
+                            "must denote a valid group id and match the pattern " + ID);
+                }
+            }
+        }
+
+        List<Server> servers = settings.getServers();
+
+        if (servers != null) {
+            Set<String> serverIds = new HashSet<>();
+
+            for (int i = 0; i < servers.size(); i++) {
+                Server server = servers.get(i);
+
+                validateStringNotEmpty(problems, "servers.server[" + i + "].id", server.getId(), null);
+
+                if (!serverIds.add(server.getId())) {
+                    addViolation(
+                            problems,
+                            BuilderProblem.Severity.WARNING,
+                            "servers.server.id",
+                            null,
+                            "must be unique but found duplicate server with id " + server.getId());
+                }
+            }
+        }
+
+        List<Mirror> mirrors = settings.getMirrors();
+
+        if (mirrors != null) {
+            for (Mirror mirror : mirrors) {
+                validateStringNotEmpty(problems, "mirrors.mirror.id", mirror.getId(), mirror.getUrl());
+
+                validateBannedCharacters(
+                        problems,
+                        "mirrors.mirror.id",
+                        BuilderProblem.Severity.WARNING,
+                        mirror.getId(),
+                        null,
+                        ILLEGAL_REPO_ID_CHARS);
+
+                if ("local".equals(mirror.getId())) {
+                    addViolation(
+                            problems,
+                            BuilderProblem.Severity.WARNING,
+                            "mirrors.mirror.id",
+                            null,
+                            "must not be 'local'"
+                                    + ", this identifier is reserved for the local repository"
+                                    + ", using it for other repositories will corrupt your repository metadata.");
+                }
+
+                validateStringNotEmpty(problems, "mirrors.mirror.url", mirror.getUrl(), mirror.getId());
+
+                validateStringNotEmpty(problems, "mirrors.mirror.mirrorOf", mirror.getMirrorOf(), mirror.getId());
+            }
+        }
+
+        List<Profile> profiles = settings.getProfiles();
+
+        if (profiles != null) {
+            Set<String> profileIds = new HashSet<>();
+
+            for (Profile profile : profiles) {
+                if (!profileIds.add(profile.getId())) {
+                    addViolation(
+                            problems,
+                            BuilderProblem.Severity.WARNING,
+                            "profiles.profile.id",
+                            null,
+                            "must be unique but found duplicate profile with id " + profile.getId());
+                }
+
+                String prefix = "profiles.profile[" + profile.getId() + "].";
+
+                validateRepositories(problems, profile.getRepositories(), prefix + "repositories.repository");
+                validateRepositories(
+                        problems, profile.getPluginRepositories(), prefix + "pluginRepositories.pluginRepository");
+            }
+        }
+
+        List<Proxy> proxies = settings.getProxies();
+
+        if (proxies != null) {
+            Set<String> proxyIds = new HashSet<>();
+
+            for (Proxy proxy : proxies) {
+                if (!proxyIds.add(proxy.getId())) {
+                    addViolation(
+                            problems,
+                            BuilderProblem.Severity.WARNING,
+                            "proxies.proxy.id",
+                            null,
+                            "must be unique but found duplicate proxy with id " + proxy.getId());
+                }
+                validateStringNotEmpty(problems, "proxies.proxy.host", proxy.getHost(), proxy.getId());
+
+                try {
+                    Integer.parseInt(proxy.getPortString());
+                } catch (NumberFormatException e) {
+                    addViolation(
+                            problems,
+                            BuilderProblem.Severity.ERROR,
+                            "proxies.proxy[" + proxy.getId() + "].port",
+                            null,
+                            "must be a valid integer but found '" + proxy.getPortString() + "'");
+                }
+            }
+        }
+    }
+
+    private void validateRepositories(List<BuilderProblem> problems, List<Repository> repositories, String prefix) {
+        Set<String> repoIds = new HashSet<>();
+
+        for (Repository repository : repositories) {
+            validateStringNotEmpty(problems, prefix + ".id", repository.getId(), repository.getUrl());
+
+            validateBannedCharacters(
+                    problems,
+                    prefix + ".id",
+                    BuilderProblem.Severity.WARNING,
+                    repository.getId(),
+                    null,
+                    ILLEGAL_REPO_ID_CHARS);
+
+            if ("local".equals(repository.getId())) {
+                addViolation(
+                        problems,
+                        BuilderProblem.Severity.WARNING,
+                        prefix + ".id",
+                        null,
+                        "must not be 'local'"
+                                + ", this identifier is reserved for the local repository"
+                                + ", using it for other repositories will corrupt your repository metadata.");
+            }
+
+            if (!repoIds.add(repository.getId())) {
+                addViolation(
+                        problems,
+                        BuilderProblem.Severity.WARNING,
+                        prefix + ".id",
+                        null,
+                        "must be unique but found duplicate repository with id " + repository.getId());
+            }
+
+            validateStringNotEmpty(problems, prefix + ".url", repository.getUrl(), repository.getId());
+
+            if ("legacy".equals(repository.getLayout())) {
+                addViolation(
+                        problems,
+                        BuilderProblem.Severity.WARNING,
+                        prefix + ".layout",
+                        repository.getId(),
+                        "uses the unsupported value 'legacy', artifact resolution might fail.");
+            }
+        }
+    }
+
+    // ----------------------------------------------------------------------
+    // Field validation
+    // ----------------------------------------------------------------------
+
+    /**
+     * Asserts:
+     * <p/>
+     * <ul>
+     * <li><code>string.length == null</code>
+     * <li><code>string.length == 0</code>
+     * </ul>
+     */
+    private static boolean validateStringEmpty(
+            List<BuilderProblem> problems, String fieldName, String string, String message) {
+        if (string == null || string.length() == 0) {
+            return true;
+        }
+
+        addViolation(problems, BuilderProblem.Severity.WARNING, fieldName, null, message);
+
+        return false;
+    }
+
+    /**
+     * Asserts:
+     * <p/>
+     * <ul>
+     * <li><code>string.length != null</code>
+     * <li><code>string.length > 0</code>
+     * </ul>
+     */
+    private static boolean validateStringNotEmpty(
+            List<BuilderProblem> problems, String fieldName, String string, String sourceHint) {
+        if (!validateNotNull(problems, fieldName, string, sourceHint)) {
+            return false;
+        }
+
+        if (!string.isEmpty()) {
+            return true;
+        }
+
+        addViolation(problems, BuilderProblem.Severity.ERROR, fieldName, sourceHint, "is missing");
+
+        return false;
+    }
+
+    /**
+     * Asserts:
+     * <p/>
+     * <ul>
+     * <li><code>string != null</code>
+     * </ul>
+     */
+    private static boolean validateNotNull(
+            List<BuilderProblem> problems, String fieldName, Object object, String sourceHint) {
+        if (object != null) {
+            return true;
+        }
+
+        addViolation(problems, BuilderProblem.Severity.ERROR, fieldName, sourceHint, "is missing");
+
+        return false;
+    }
+
+    private static boolean validateBannedCharacters(
+            List<BuilderProblem> problems,
+            String fieldName,
+            BuilderProblem.Severity severity,
+            String string,
+            String sourceHint,
+            String banned) {
+        if (string != null) {
+            for (int i = string.length() - 1; i >= 0; i--) {
+                if (banned.indexOf(string.charAt(i)) >= 0) {
+                    addViolation(
+                            problems,
+                            severity,
+                            fieldName,
+                            sourceHint,
+                            "must not contain any of these characters " + banned + " but found " + string.charAt(i));
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    private static void addViolation(
+            List<BuilderProblem> problems,
+            BuilderProblem.Severity severity,
+            String fieldName,
+            String sourceHint,
+            String message) {
+        StringBuilder buffer = new StringBuilder(256);
+        buffer.append('\'').append(fieldName).append('\'');
+
+        if (sourceHint != null) {
+            buffer.append(" for ").append(sourceHint);
+        }
+
+        buffer.append(' ').append(message);
+
+        problems.add(new DefaultBuilderProblem(null, -1, -1, null, buffer.toString(), severity));
+    }
+}

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultSettingsXmlFactory.java

@@ -18,15 +18,14 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.Reader;
 import java.io.Writer;
 
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.xml.SettingsXmlFactory;
 import org.apache.maven.api.services.xml.XmlReaderException;
 import org.apache.maven.api.services.xml.XmlReaderRequest;
@@ -37,7 +36,8 @@ import org.apache.maven.api.settings.Settings;
 import org.apache.maven.settings.v4.SettingsStaxReader;
 import org.apache.maven.settings.v4.SettingsStaxWriter;
 
-import static org.apache.maven.internal.impl.Utils.nonNull;
+import static org.apache.maven.internal.impl.StaxLocation.getLocation;
+import static org.apache.maven.internal.impl.StaxLocation.getMessage;
 
 @Named
 @Singleton
@@ -63,7 +63,7 @@ public class DefaultSettingsXmlFactory implements SettingsXmlFactory {
                 return xml.read(inputStream, request.isStrict(), source);
             }
         } catch (Exception e) {
-            throw new XmlReaderException("Unable to read settings", e);
+            throw new XmlReaderException("Unable to read settings: " + getMessage(e), getLocation(e), e);
         }
     }
 
@@ -83,7 +83,14 @@ public class DefaultSettingsXmlFactory implements SettingsXmlFactory {
                 new SettingsStaxWriter().write(outputStream, content);
             }
         } catch (Exception e) {
-            throw new XmlWriterException("Unable to write settings", e);
+            throw new XmlWriterException("Unable to write settings: " + getMessage(e), getLocation(e), e);
         }
     }
+
+    static <T> T nonNull(T t, String name) {
+        if (t == null) {
+            throw new IllegalArgumentException(name + " cannot be null");
+        }
+        return t;
+    }
 }

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultToolchainsBuilder.java

@@ -0,0 +1,218 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import javax.xml.stream.Location;
+import javax.xml.stream.XMLStreamException;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.services.Source;
+import org.apache.maven.api.services.ToolchainsBuilder;
+import org.apache.maven.api.services.ToolchainsBuilderException;
+import org.apache.maven.api.services.ToolchainsBuilderRequest;
+import org.apache.maven.api.services.ToolchainsBuilderResult;
+import org.apache.maven.api.services.xml.ToolchainsXmlFactory;
+import org.apache.maven.api.services.xml.XmlReaderException;
+import org.apache.maven.api.services.xml.XmlReaderRequest;
+import org.apache.maven.api.toolchain.PersistedToolchains;
+import org.apache.maven.toolchain.v4.MavenToolchainsMerger;
+import org.apache.maven.toolchain.v4.MavenToolchainsTransformer;
+import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
+import org.codehaus.plexus.interpolation.InterpolationException;
+import org.codehaus.plexus.interpolation.MapBasedValueSource;
+import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
+
+/**
+ * Builds the effective toolchains from a user toolchains file and/or a global toolchains file.
+ *
+ */
+@Named
+public class DefaultToolchainsBuilder implements ToolchainsBuilder {
+
+    private final MavenToolchainsMerger toolchainsMerger = new MavenToolchainsMerger();
+
+    @Override
+    public ToolchainsBuilderResult build(ToolchainsBuilderRequest request) throws ToolchainsBuilderException {
+        List<BuilderProblem> problems = new ArrayList<>();
+
+        Source globalSource = request.getGlobalToolchainsSource().orElse(null);
+        PersistedToolchains global = readToolchains(globalSource, request, problems);
+
+        Source userSource = request.getUserToolchainsSource().orElse(null);
+        PersistedToolchains user = readToolchains(userSource, request, problems);
+
+        PersistedToolchains effective = toolchainsMerger.merge(user, global, false, null);
+
+        if (hasErrors(problems)) {
+            throw new ToolchainsBuilderException("Error building toolchains", problems);
+        }
+
+        return new DefaultToolchainsBuilderResult(effective, problems);
+    }
+
+    private boolean hasErrors(List<BuilderProblem> problems) {
+        if (problems != null) {
+            for (BuilderProblem problem : problems) {
+                if (BuilderProblem.Severity.ERROR.compareTo(problem.getSeverity()) >= 0) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    private PersistedToolchains readToolchains(
+            Source toolchainsSource, ToolchainsBuilderRequest request, List<BuilderProblem> problems) {
+        if (toolchainsSource == null) {
+            return PersistedToolchains.newInstance();
+        }
+
+        PersistedToolchains toolchains;
+
+        try {
+            try {
+                InputStream is = toolchainsSource.openStream();
+                if (is == null) {
+                    return PersistedToolchains.newInstance();
+                }
+                toolchains = request.getSession()
+                        .getService(ToolchainsXmlFactory.class)
+                        .read(XmlReaderRequest.builder()
+                                .inputStream(is)
+                                .location(toolchainsSource.getLocation())
+                                .strict(true)
+                                .build());
+            } catch (XmlReaderException e) {
+                InputStream is = toolchainsSource.openStream();
+                if (is == null) {
+                    return PersistedToolchains.newInstance();
+                }
+                toolchains = request.getSession()
+                        .getService(ToolchainsXmlFactory.class)
+                        .read(XmlReaderRequest.builder()
+                                .inputStream(is)
+                                .location(toolchainsSource.getLocation())
+                                .strict(false)
+                                .build());
+                Location loc = e.getCause() instanceof XMLStreamException xe ? xe.getLocation() : null;
+                problems.add(new DefaultBuilderProblem(
+                        toolchainsSource.getLocation(),
+                        loc != null ? loc.getLineNumber() : -1,
+                        loc != null ? loc.getColumnNumber() : -1,
+                        e,
+                        e.getMessage(),
+                        BuilderProblem.Severity.WARNING));
+            }
+        } catch (XmlReaderException e) {
+            Location loc = e.getCause() instanceof XMLStreamException xe ? xe.getLocation() : null;
+            problems.add(new DefaultBuilderProblem(
+                    toolchainsSource.getLocation(),
+                    loc != null ? loc.getLineNumber() : -1,
+                    loc != null ? loc.getColumnNumber() : -1,
+                    e,
+                    "Non-parseable toolchains " + toolchainsSource.getLocation() + ": " + e.getMessage(),
+                    BuilderProblem.Severity.FATAL));
+            return PersistedToolchains.newInstance();
+        } catch (IOException e) {
+            problems.add(new DefaultBuilderProblem(
+                    toolchainsSource.getLocation(),
+                    -1,
+                    -1,
+                    e,
+                    "Non-readable toolchains " + toolchainsSource.getLocation() + ": " + e.getMessage(),
+                    BuilderProblem.Severity.FATAL));
+            return PersistedToolchains.newInstance();
+        }
+
+        toolchains = interpolate(toolchains, request, problems);
+
+        return toolchains;
+    }
+
+    private PersistedToolchains interpolate(
+            PersistedToolchains toolchains, ToolchainsBuilderRequest request, List<BuilderProblem> problems) {
+
+        RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
+
+        interpolator.addValueSource(new MapBasedValueSource(request.getSession().getUserProperties()));
+
+        interpolator.addValueSource(new MapBasedValueSource(request.getSession().getSystemProperties()));
+
+        try {
+            interpolator.addValueSource(new EnvarBasedValueSource());
+        } catch (IOException e) {
+            problems.add(new DefaultBuilderProblem(
+                    null,
+                    -1,
+                    -1,
+                    e,
+                    "Failed to use environment variables for interpolation: " + e.getMessage(),
+                    BuilderProblem.Severity.WARNING));
+        }
+
+        return new MavenToolchainsTransformer(value -> {
+                    try {
+                        return value != null ? interpolator.interpolate(value) : null;
+                    } catch (InterpolationException e) {
+                        problems.add(new DefaultBuilderProblem(
+                                null,
+                                -1,
+                                -1,
+                                e,
+                                "Failed to interpolate toolchains: " + e.getMessage(),
+                                BuilderProblem.Severity.WARNING));
+                        return value;
+                    }
+                })
+                .visit(toolchains);
+    }
+
+    /**
+     * Collects the output of the toolchains builder.
+     *
+     */
+    static class DefaultToolchainsBuilderResult implements ToolchainsBuilderResult {
+
+        private final PersistedToolchains effectiveToolchains;
+
+        private final List<BuilderProblem> problems;
+
+        DefaultToolchainsBuilderResult(PersistedToolchains effectiveToolchains, List<BuilderProblem> problems) {
+            this.effectiveToolchains = effectiveToolchains;
+            this.problems = (problems != null) ? problems : new ArrayList<>();
+        }
+
+        @Override
+        public PersistedToolchains getEffectiveToolchains() {
+            return effectiveToolchains;
+        }
+
+        @Override
+        public List<BuilderProblem> getProblems() {
+            return problems;
+        }
+    }
+}

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultToolchainsXmlFactory.java

@@ -18,9 +18,6 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.Reader;
@@ -28,6 +25,8 @@ import java.io.Writer;
 import java.util.Objects;
 
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.model.InputSource;
 import org.apache.maven.api.services.xml.ToolchainsXmlFactory;
 import org.apache.maven.api.services.xml.XmlReaderException;
@@ -38,6 +37,8 @@ import org.apache.maven.api.toolchain.PersistedToolchains;
 import org.apache.maven.toolchain.v4.MavenToolchainsStaxReader;
 import org.apache.maven.toolchain.v4.MavenToolchainsStaxWriter;
 
+import static org.apache.maven.internal.impl.StaxLocation.getLocation;
+import static org.apache.maven.internal.impl.StaxLocation.getMessage;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -64,7 +65,7 @@ public class DefaultToolchainsXmlFactory implements ToolchainsXmlFactory {
                 return xml.read(inputStream, request.isStrict());
             }
         } catch (Exception e) {
-            throw new XmlReaderException("Unable to read toolchains", e);
+            throw new XmlReaderException("Unable to read toolchains: " + getMessage(e), getLocation(e), e);
         }
     }
 
@@ -84,7 +85,7 @@ public class DefaultToolchainsXmlFactory implements ToolchainsXmlFactory {
                 new MavenToolchainsStaxWriter().write(outputStream, content);
             }
         } catch (Exception e) {
-            throw new XmlWriterException("Unable to write toolchains", e);
+            throw new XmlWriterException("Unable to write toolchains: " + getMessage(e), getLocation(e), e);
         }
     }
 }

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultTransport.java

@@ -18,9 +18,6 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.net.URI;
@@ -29,6 +26,8 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Optional;
 
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.Transport;
 import org.eclipse.aether.spi.connector.transport.GetTask;
 import org.eclipse.aether.spi.connector.transport.PutTask;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultTransportProvider.java

@@ -18,15 +18,14 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.net.URI;
 import java.net.URISyntaxException;
 
 import org.apache.maven.api.RemoteRepository;
 import org.apache.maven.api.Session;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.Transport;
 import org.apache.maven.api.services.TransportProvider;
 import org.apache.maven.api.services.TransportProviderException;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultVersionParser.java

@@ -18,13 +18,12 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import org.apache.maven.api.Version;
 import org.apache.maven.api.VersionConstraint;
 import org.apache.maven.api.VersionRange;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.VersionParser;
 import org.apache.maven.model.version.ModelVersionParser;
 

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultVersionRangeResolver.java

@@ -18,10 +18,6 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -29,6 +25,9 @@ import java.util.stream.Collectors;
 
 import org.apache.maven.api.Repository;
 import org.apache.maven.api.Version;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.VersionRangeResolver;
 import org.apache.maven.api.services.VersionRangeResolverException;
 import org.apache.maven.api.services.VersionRangeResolverRequest;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/DefaultVersionResolver.java

@@ -18,15 +18,14 @@
  */
 package org.apache.maven.internal.impl;
 
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
 import java.util.List;
 import java.util.Optional;
 
 import org.apache.maven.api.Repository;
 import org.apache.maven.api.Version;
+import org.apache.maven.api.di.Inject;
+import org.apache.maven.api.di.Named;
+import org.apache.maven.api.di.Singleton;
 import org.apache.maven.api.services.VersionResolver;
 import org.apache.maven.api.services.VersionResolverException;
 import org.apache.maven.api.services.VersionResolverRequest;

maven-api-impl/src/main/java/org/apache/maven/internal/impl/InternalSession.java

@@ -27,11 +27,9 @@ import org.apache.maven.api.Dependency;
 import org.apache.maven.api.DependencyCoordinate;
 import org.apache.maven.api.LocalRepository;
 import org.apache.maven.api.Node;
-import org.apache.maven.api.Project;
 import org.apache.maven.api.RemoteRepository;
 import org.apache.maven.api.Session;
 import org.apache.maven.api.annotations.Nonnull;
-import org.apache.maven.execution.MavenSession;
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
 
@@ -55,21 +53,12 @@ public interface InternalSession extends Session {
     @Nonnull
     Dependency getDependency(@Nonnull org.eclipse.aether.graph.Dependency dependency);
 
-    List<Project> getProjects(List<org.apache.maven.project.MavenProject> projects);
-
-    Project getProject(org.apache.maven.project.MavenProject project);
-
     List<org.eclipse.aether.repository.RemoteRepository> toRepositories(List<RemoteRepository> repositories);
 
     org.eclipse.aether.repository.RemoteRepository toRepository(RemoteRepository repository);
 
     org.eclipse.aether.repository.LocalRepository toRepository(LocalRepository repository);
 
-    List<org.apache.maven.artifact.repository.ArtifactRepository> toArtifactRepositories(
-            List<RemoteRepository> repositories);
-
-    org.apache.maven.artifact.repository.ArtifactRepository toArtifactRepository(RemoteRepository repository);
-
     List<org.eclipse.aether.graph.Dependency> toDependencies(
             Collection<DependencyCoordinate> dependencies, boolean managed);
 
@@ -81,8 +70,6 @@ public interface InternalSession extends Session {
 
     org.eclipse.aether.artifact.Artifact toArtifact(ArtifactCoordinate coord);
 
-    MavenSession getMavenSession();
-
     RepositorySystemSession getSession();
 
     RepositorySystem getRepositorySystem();

maven-api-impl/src/main/java/org/apache/maven/internal/impl/SettingsUtilsV4.java

@@ -16,7 +16,7 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-package org.apache.maven.settings;
+package org.apache.maven.internal.impl;
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
@@ -311,17 +311,6 @@ public final class SettingsUtilsV4 {
         return policy;
     }
 
-    /**
-     * @param settings could be null
-     * @return a new instance of settings or null if settings was null.
-     */
-    public static org.apache.maven.settings.Settings copySettings(org.apache.maven.settings.Settings settings) {
-        if (settings == null) {
-            return null;
-        }
-        return new org.apache.maven.settings.Settings(settings.getDelegate());
-    }
-
     private static org.apache.maven.api.model.InputLocation toLocation(
             org.apache.maven.api.settings.InputLocation location) {
         if (location != null) {

maven-api-impl/src/main/java/org/apache/maven/internal/impl/StaxLocation.java

@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import javax.xml.stream.XMLStreamException;
+
+import org.apache.maven.api.services.xml.Location;
+
+public class StaxLocation implements Location {
+
+    private final javax.xml.stream.Location location;
+
+    public static Location getLocation(Exception e) {
+        return toLocation(e instanceof XMLStreamException xe ? xe.getLocation() : null);
+    }
+
+    public static Location toLocation(javax.xml.stream.Location location) {
+        return location != null ? new StaxLocation(location) : null;
+    }
+
+    public static String getMessage(Exception e) {
+        String message = e.getMessage();
+        if (e instanceof XMLStreamException xe && xe.getLocation() != null) {
+            int idx = message.indexOf("\nMessage: ");
+            if (idx >= 0) {
+                return message.substring(idx + "\nMessage: ".length());
+            }
+        }
+        return message;
+    }
+
+    public StaxLocation(javax.xml.stream.Location location) {
+        this.location = location;
+    }
+
+    @Override
+    public int getLineNumber() {
+        return location.getLineNumber();
+    }
+
+    @Override
+    public int getColumnNumber() {
+        return location.getColumnNumber();
+    }
+
+    @Override
+    public int getCharacterOffset() {
+        return location.getCharacterOffset();
+    }
+
+    @Override
+    public String getPublicId() {
+        return location.getPublicId();
+    }
+
+    @Override
+    public String getSystemId() {
+        return location.getSystemId();
+    }
+}

maven-api-impl/src/test/java/org/apache/maven/internal/impl/DefaultSettingsBuilderFactoryTest.java

@@ -0,0 +1,80 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.apache.maven.api.Session;
+import org.apache.maven.api.services.SettingsBuilder;
+import org.apache.maven.api.services.SettingsBuilderRequest;
+import org.apache.maven.api.services.SettingsBuilderResult;
+import org.apache.maven.api.services.Source;
+import org.apache.maven.api.services.xml.SettingsXmlFactory;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/**
+ */
+@ExtendWith(MockitoExtension.class)
+class DefaultSettingsBuilderFactoryTest {
+
+    @Mock
+    Session session;
+
+    @BeforeEach
+    void setup() {
+        Map<String, String> map = System.getProperties().entrySet().stream()
+                .collect(Collectors.toMap(
+                        e -> e.getKey().toString(), e -> e.getValue().toString()));
+        //        lenient().when(session.getSystemProperties()).thenReturn(map);
+        //        lenient().when(session.getUserProperties()).thenReturn(Collections.emptyMap());
+
+        Mockito.lenient()
+                .when(session.getService(SettingsXmlFactory.class))
+                .thenReturn(new DefaultSettingsXmlFactory());
+    }
+
+    @Test
+    void testCompleteWiring() {
+        SettingsBuilder builder = new DefaultSettingsBuilder();
+        assertNotNull(builder);
+
+        SettingsBuilderRequest request = SettingsBuilderRequest.builder()
+                .session(session)
+                .userSettingsSource(Source.fromPath(getSettings("settings-simple")))
+                .build();
+
+        SettingsBuilderResult result = builder.build(request);
+        assertNotNull(result);
+        assertNotNull(result.getEffectiveSettings());
+    }
+
+    private Path getSettings(String name) {
+        return Paths.get("src/test/resources/" + name + ".xml").toAbsolutePath();
+    }
+}

maven-api-impl/src/test/java/org/apache/maven/internal/impl/DefaultSettingsValidatorTest.java

@@ -0,0 +1,234 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import java.util.List;
+
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.services.SettingsBuilder;
+import org.apache.maven.api.settings.Profile;
+import org.apache.maven.api.settings.Repository;
+import org.apache.maven.api.settings.Settings;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ */
+class DefaultSettingsValidatorTest {
+
+    private SettingsBuilder validator;
+
+    @BeforeEach
+    void setUp() throws Exception {
+        validator = new DefaultSettingsBuilder();
+    }
+
+    @AfterEach
+    void tearDown() throws Exception {
+        validator = null;
+    }
+
+    private void assertContains(String msg, String substring) {
+        assertTrue(msg.contains(substring), "\"" + substring + "\" was not found in: " + msg);
+    }
+
+    @Test
+    void testValidate() {
+        Profile prof = Profile.newBuilder().id("xxx").build();
+        Settings model = Settings.newBuilder().profiles(List.of(prof)).build();
+        List<BuilderProblem> problems = validator.validate(model);
+        assertEquals(0, problems.size());
+
+        Repository repo = org.apache.maven.api.settings.Repository.newInstance(false);
+        Settings model2 = Settings.newBuilder()
+                .profiles(List.of(prof.withRepositories(List.of(repo))))
+                .build();
+        problems.clear();
+        problems = validator.validate(model2);
+        assertEquals(2, problems.size());
+
+        repo = repo.withUrl("http://xxx.xxx.com");
+        model2 = Settings.newBuilder()
+                .profiles(List.of(prof.withRepositories(List.of(repo))))
+                .build();
+        problems.clear();
+        problems = validator.validate(model2);
+        assertEquals(1, problems.size());
+
+        repo = repo.withId("xxx");
+        model2 = Settings.newBuilder()
+                .profiles(List.of(prof.withRepositories(List.of(repo))))
+                .build();
+        problems.clear();
+        problems = validator.validate(model2);
+        assertEquals(0, problems.size());
+    }
+
+    /*
+    @Test
+    void testValidateMirror() throws Exception {
+        Settings settings = new Settings();
+        Mirror mirror = new Mirror();
+        mirror.setId("local");
+        settings.addMirror(mirror);
+        mirror = new Mirror();
+        mirror.setId("illegal\\:/chars");
+        mirror.setUrl("http://void");
+        mirror.setMirrorOf("void");
+        settings.addMirror(mirror);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(4, problems.messages.size());
+        assertContains(problems.messages.get(0), "'mirrors.mirror.id' must not be 'local'");
+        assertContains(problems.messages.get(1), "'mirrors.mirror.url' for local is missing");
+        assertContains(problems.messages.get(2), "'mirrors.mirror.mirrorOf' for local is missing");
+        assertContains(problems.messages.get(3), "'mirrors.mirror.id' must not contain any of these characters");
+    }
+
+    @Test
+    void testValidateRepository() throws Exception {
+        Profile profile = new Profile();
+        Repository repo = new Repository();
+        repo.setId("local");
+        profile.addRepository(repo);
+        repo = new Repository();
+        repo.setId("illegal\\:/chars");
+        repo.setUrl("http://void");
+        profile.addRepository(repo);
+        Settings settings = new Settings();
+        settings.addProfile(profile);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(3, problems.messages.size());
+        assertContains(
+                problems.messages.get(0), "'profiles.profile[default].repositories.repository.id' must not be 'local'");
+        assertContains(
+                problems.messages.get(1),
+                "'profiles.profile[default].repositories.repository.url' for local is missing");
+        assertContains(
+                problems.messages.get(2),
+                "'profiles.profile[default].repositories.repository.id' must not contain any of these characters");
+    }
+
+    @Test
+    void testValidateUniqueServerId() throws Exception {
+        Settings settings = new Settings();
+        Server server1 = new Server();
+        server1.setId("test");
+        settings.addServer(server1);
+        Server server2 = new Server();
+        server2.setId("test");
+        settings.addServer(server2);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(1, problems.messages.size());
+        assertContains(
+                problems.messages.get(0), "'servers.server.id' must be unique but found duplicate server with id test");
+    }
+
+    @Test
+    void testValidateUniqueProfileId() throws Exception {
+        Settings settings = new Settings();
+        Profile profile1 = new Profile();
+        profile1.setId("test");
+        settings.addProfile(profile1);
+        Profile profile2 = new Profile();
+        profile2.setId("test");
+        settings.addProfile(profile2);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(1, problems.messages.size());
+        assertContains(
+                problems.messages.get(0),
+                "'profiles.profile.id' must be unique but found duplicate profile with id test");
+    }
+
+    @Test
+    void testValidateUniqueRepositoryId() throws Exception {
+        Settings settings = new Settings();
+        Profile profile = new Profile();
+        profile.setId("pro");
+        settings.addProfile(profile);
+        Repository repo1 = new Repository();
+        repo1.setUrl("http://apache.org/");
+        repo1.setId("test");
+        profile.addRepository(repo1);
+        Repository repo2 = new Repository();
+        repo2.setUrl("http://apache.org/");
+        repo2.setId("test");
+        profile.addRepository(repo2);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(1, problems.messages.size());
+        assertContains(
+                problems.messages.get(0),
+                "'profiles.profile[pro].repositories.repository.id' must be unique"
+                        + " but found duplicate repository with id test");
+    }
+
+    @Test
+    void testValidateUniqueProxyId() throws Exception {
+        Settings settings = new Settings();
+        Proxy proxy = new Proxy();
+        String id = "foo";
+        proxy.setId(id);
+        proxy.setHost("www.example.com");
+        settings.addProxy(proxy);
+        settings.addProxy(proxy);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(1, problems.messages.size());
+        assertContains(
+                problems.messages.get(0),
+                "'proxies.proxy.id' must be unique" + " but found duplicate proxy with id " + id);
+    }
+
+    @Test
+    void testValidateProxy() throws Exception {
+        Settings settings = new Settings();
+        Proxy proxy1 = new Proxy();
+        settings.addProxy(proxy1);
+
+        SimpleProblemCollector problems = new SimpleProblemCollector();
+        validator.validate(settings, problems);
+        assertEquals(1, problems.messages.size());
+        assertContains(problems.messages.get(0), "'proxies.proxy.host' for default is missing");
+    }
+
+    private static class SimpleProblemCollector implements SettingsProblemCollector {
+
+        public List<String> messages = new ArrayList<>();
+
+        public void add(Severity severity, String message, int line, int column, Exception cause) {
+            messages.add(message);
+        }
+    }
+
+     */
+}

maven-api-impl/src/test/java/org/apache/maven/internal/impl/standalone/ApiRunner.java

@@ -0,0 +1,336 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl.standalone;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.Instant;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.maven.api.Artifact;
+import org.apache.maven.api.Project;
+import org.apache.maven.api.RemoteRepository;
+import org.apache.maven.api.Session;
+import org.apache.maven.api.Version;
+import org.apache.maven.api.di.Provides;
+import org.apache.maven.api.services.ArtifactManager;
+import org.apache.maven.api.services.Lookup;
+import org.apache.maven.api.services.MavenException;
+import org.apache.maven.api.services.RepositoryFactory;
+import org.apache.maven.api.services.SettingsBuilder;
+import org.apache.maven.api.settings.Settings;
+import org.apache.maven.di.Injector;
+import org.apache.maven.di.Key;
+import org.apache.maven.di.impl.DIException;
+import org.apache.maven.internal.impl.AbstractSession;
+import org.apache.maven.internal.impl.DefaultArtifactCoordinateFactory;
+import org.apache.maven.internal.impl.DefaultArtifactDeployer;
+import org.apache.maven.internal.impl.DefaultArtifactFactory;
+import org.apache.maven.internal.impl.DefaultArtifactInstaller;
+import org.apache.maven.internal.impl.DefaultArtifactResolver;
+import org.apache.maven.internal.impl.DefaultChecksumAlgorithmService;
+import org.apache.maven.internal.impl.DefaultDependencyCollector;
+import org.apache.maven.internal.impl.DefaultDependencyCoordinateFactory;
+import org.apache.maven.internal.impl.DefaultLocalRepositoryManager;
+import org.apache.maven.internal.impl.DefaultMessageBuilderFactory;
+import org.apache.maven.internal.impl.DefaultModelXmlFactory;
+import org.apache.maven.internal.impl.DefaultRepositoryFactory;
+import org.apache.maven.internal.impl.DefaultSettingsBuilder;
+import org.apache.maven.internal.impl.DefaultSettingsXmlFactory;
+import org.apache.maven.internal.impl.DefaultToolchainsBuilder;
+import org.apache.maven.internal.impl.DefaultToolchainsXmlFactory;
+import org.apache.maven.internal.impl.DefaultTransportProvider;
+import org.apache.maven.internal.impl.DefaultVersionParser;
+import org.apache.maven.internal.impl.DefaultVersionRangeResolver;
+import org.apache.maven.internal.impl.DefaultVersionResolver;
+import org.apache.maven.model.path.DefaultPathTranslator;
+import org.apache.maven.model.path.ProfileActivationFilePathInterpolator;
+import org.apache.maven.model.profile.DefaultProfileSelector;
+import org.apache.maven.model.profile.activation.FileProfileActivator;
+import org.apache.maven.model.profile.activation.JdkVersionProfileActivator;
+import org.apache.maven.model.profile.activation.OperatingSystemProfileActivator;
+import org.apache.maven.model.profile.activation.PropertyProfileActivator;
+import org.apache.maven.model.root.DefaultRootLocator;
+import org.apache.maven.repository.internal.DefaultModelVersionParser;
+import org.eclipse.aether.DefaultRepositorySystemSession;
+import org.eclipse.aether.RepositorySystem;
+import org.eclipse.aether.RepositorySystemSession;
+import org.eclipse.aether.repository.LocalRepository;
+import org.eclipse.aether.repository.LocalRepositoryManager;
+import org.eclipse.aether.supplier.RepositorySystemSupplier;
+import org.eclipse.aether.util.version.GenericVersionScheme;
+
+public class ApiRunner {
+
+    /**
+     * Create a new session.
+     */
+    public static Session createSession() {
+        Injector injector = Injector.create();
+        injector.bindInstance(Injector.class, injector);
+        injector.bindImplicit(ApiRunner.class);
+        injector.bindImplicit(DefaultArtifactCoordinateFactory.class);
+        injector.bindImplicit(DefaultArtifactDeployer.class);
+        injector.bindImplicit(DefaultArtifactFactory.class);
+        injector.bindImplicit(DefaultArtifactInstaller.class);
+        injector.bindImplicit(DefaultArtifactResolver.class);
+        injector.bindImplicit(DefaultChecksumAlgorithmService.class);
+        injector.bindImplicit(DefaultDependencyCollector.class);
+        injector.bindImplicit(DefaultDependencyCoordinateFactory.class);
+        injector.bindImplicit(DefaultLocalRepositoryManager.class);
+        injector.bindImplicit(DefaultMessageBuilderFactory.class);
+        injector.bindImplicit(DefaultModelXmlFactory.class);
+        injector.bindImplicit(DefaultRepositoryFactory.class);
+        injector.bindImplicit(DefaultSettingsBuilder.class);
+        injector.bindImplicit(DefaultSettingsXmlFactory.class);
+        injector.bindImplicit(DefaultToolchainsBuilder.class);
+        injector.bindImplicit(DefaultToolchainsXmlFactory.class);
+        injector.bindImplicit(DefaultTransportProvider.class);
+        injector.bindImplicit(DefaultVersionParser.class);
+        injector.bindImplicit(DefaultVersionRangeResolver.class);
+        injector.bindImplicit(DefaultVersionResolver.class);
+
+        return injector.getInstance(Session.class);
+    }
+
+    static class DefaultSession extends AbstractSession {
+
+        DefaultSession(RepositorySystemSession session, RepositorySystem repositorySystem, Lookup lookup) {
+            this(session, repositorySystem, Collections.emptyList(), null, lookup);
+        }
+
+        protected DefaultSession(
+                RepositorySystemSession session,
+                RepositorySystem repositorySystem,
+                List<RemoteRepository> repositories,
+                List<org.eclipse.aether.repository.RemoteRepository> resolverRepositories,
+                Lookup lookup) {
+            super(session, repositorySystem, repositories, resolverRepositories, lookup);
+        }
+
+        @Override
+        protected Session newSession(RepositorySystemSession session, List<RemoteRepository> repositories) {
+            return new DefaultSession(session, repositorySystem, repositories, null, lookup);
+        }
+
+        @Override
+        public Settings getSettings() {
+            return null;
+        }
+
+        @Override
+        public Map<String, String> getUserProperties() {
+            return null;
+        }
+
+        @Override
+        public Map<String, String> getSystemProperties() {
+            return null;
+        }
+
+        @Override
+        public Map<String, String> getEffectiveProperties(Project project) {
+            return null;
+        }
+
+        @Override
+        public Version getMavenVersion() {
+            return null;
+        }
+
+        @Override
+        public int getDegreeOfConcurrency() {
+            return 0;
+        }
+
+        @Override
+        public Instant getStartTime() {
+            return null;
+        }
+
+        @Override
+        public Path getTopDirectory() {
+            return null;
+        }
+
+        @Override
+        public Path getRootDirectory() {
+            return null;
+        }
+
+        @Override
+        public List<Project> getProjects() {
+            return List.of();
+        }
+
+        @Override
+        public Map<String, Object> getPluginContext(Project project) {
+            throw new UnsupportedInStandaloneModeException();
+        }
+    }
+
+    @Provides
+    static Lookup newLookup(Injector injector) {
+        return new Lookup() {
+            @Override
+            public <T> T lookup(Class<T> type) {
+                try {
+                    return injector.getInstance(type);
+                } catch (DIException e) {
+                    throw new MavenException("Unable to locate instance of type " + type, e);
+                }
+            }
+
+            @Override
+            public <T> T lookup(Class<T> type, String name) {
+                try {
+                    return injector.getInstance(Key.of(type, name));
+                } catch (DIException e) {
+                    throw new MavenException("Unable to locate instance of type " + type, e);
+                }
+            }
+
+            @Override
+            public <T> Optional<T> lookupOptional(Class<T> type) {
+                try {
+                    return Optional.of(injector.getInstance(type));
+                } catch (DIException e) {
+                    return Optional.empty();
+                }
+            }
+
+            @Override
+            public <T> Optional<T> lookupOptional(Class<T> type, String name) {
+                try {
+                    return Optional.of(injector.getInstance(Key.of(type, name)));
+                } catch (DIException e) {
+                    return Optional.empty();
+                }
+            }
+
+            @Override
+            public <T> List<T> lookupList(Class<T> type) {
+                return injector.getInstance(new Key<List<T>>() {});
+            }
+
+            @Override
+            public <T> Map<String, T> lookupMap(Class<T> type) {
+                return injector.getInstance(new Key<Map<String, T>>() {});
+            }
+        };
+    }
+
+    @Provides
+    static ArtifactManager newArtifactManager() {
+        return new ArtifactManager() {
+            private final Map<Artifact, Path> paths = new ConcurrentHashMap<>();
+
+            @Override
+            public Optional<Path> getPath(Artifact artifact) {
+                return Optional.ofNullable(paths.get(artifact));
+            }
+
+            @Override
+            public void setPath(Artifact artifact, Path path) {
+                paths.put(artifact, path);
+            }
+        };
+    }
+
+    @Provides
+    static DefaultModelVersionParser newModelVersionParser() {
+        return new DefaultModelVersionParser(new GenericVersionScheme());
+    }
+
+    @Provides
+    static Session newSession(Lookup lookup) {
+        Map<String, String> properties = new HashMap<>();
+        // Env variables prefixed with "env."
+        System.getenv().forEach((k, v) -> properties.put("env." + k, v));
+        // Java System properties
+        System.getProperties().forEach((k, v) -> properties.put(k.toString(), v.toString()));
+
+        RepositorySystem system = new RepositorySystemSupplier().get();
+
+        // SettingsDecrypter settingsDecrypter =
+        // (SettingsDecrypter)Objects.requireNonNull(this.createSettingsDecrypter(preBoot));
+        new DefaultProfileSelector(List.of(
+                new JdkVersionProfileActivator(),
+                new PropertyProfileActivator(),
+                new OperatingSystemProfileActivator(),
+                new FileProfileActivator(new ProfileActivationFilePathInterpolator(
+                        new DefaultPathTranslator(), new DefaultRootLocator()))));
+
+        Path userHome = Paths.get(properties.get("user.home"));
+        Path mavenUserHome = userHome.resolve(".m2");
+        Path mavenSystemHome = properties.containsKey("maven.home")
+                ? Paths.get(properties.get("maven.home"))
+                : properties.containsKey("env.MAVEN_HOME") ? Paths.get(properties.get("env.MAVEN_HOME")) : null;
+
+        DefaultRepositorySystemSession rsession = new DefaultRepositorySystemSession(h -> false);
+        rsession.setSystemProperties(properties);
+        rsession.setConfigProperties(properties);
+
+        DefaultSession session = new DefaultSession(
+                rsession,
+                system,
+                List.of(lookup.lookup(RepositoryFactory.class)
+                        .createRemote("central", "https://repo.maven.apache.org/maven2")),
+                null,
+                lookup);
+
+        Settings settings = session.getService(SettingsBuilder.class)
+                .build(
+                        session,
+                        mavenSystemHome != null ? mavenSystemHome.resolve("settings.xml") : null,
+                        mavenUserHome.resolve("settings.xml"))
+                .getEffectiveSettings();
+
+        settings.getProfiles();
+
+        // local repository
+        String localRepository = settings.getLocalRepository() != null
+                ? settings.getLocalRepository()
+                : mavenUserHome.resolve("repository").toString();
+        LocalRepositoryManager llm = system.newLocalRepositoryManager(rsession, new LocalRepository(localRepository));
+        rsession.setLocalRepositoryManager(llm);
+        // active proxies
+        // TODO
+        // active profiles
+
+        DefaultSession defaultSession = new DefaultSession(
+                rsession,
+                system,
+                List.of(lookup.lookup(RepositoryFactory.class)
+                        .createRemote("central", "https://repo.maven.apache.org/maven2")),
+                null,
+                lookup);
+        //        settings.getDelegate().getRepositories().stream()
+        //                        .map(r -> SettingsUtilsV4.)
+        //        defaultSession.getService(RepositoryFactory.class).createRemote()
+        return defaultSession;
+    }
+
+    static class UnsupportedInStandaloneModeException extends MavenException {}
+}

maven-api-impl/src/test/java/org/apache/maven/internal/impl/standalone/TestApiStandalone.java

@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl.standalone;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+
+import org.apache.maven.api.Artifact;
+import org.apache.maven.api.ArtifactCoordinate;
+import org.apache.maven.api.Node;
+import org.apache.maven.api.Session;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class TestApiStandalone {
+
+    @Test
+    void testStandalone() {
+        Session session = ApiRunner.createSession();
+
+        ArtifactCoordinate coord = session.createArtifactCoordinate("org.apache.maven:maven-api-core:4.0.0-alpha-13");
+        Map.Entry<Artifact, Path> res = session.resolveArtifact(coord);
+        assertNotNull(res);
+        assertNotNull(res.getValue());
+        assertTrue(Files.exists(res.getValue()));
+
+        Node node = session.collectDependencies(session.createDependencyCoordinate(coord));
+        assertNotNull(node);
+        assertEquals(8, node.getChildren().size());
+    }
+}

maven-api-impl/src/test/resources/settings-simple.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<settings>
+  <localRepository>${user.home}/.m2/repository</localRepository>
+</settings>

maven-core/pom.xml

@@ -87,6 +87,10 @@ under the License.
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-api-spi</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-impl</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.maven.resolver</groupId>
       <artifactId>maven-resolver-api</artifactId>

maven-core/src/main/java/org/apache/maven/DefaultMaven.java

@@ -60,7 +60,7 @@ import org.apache.maven.execution.ProjectDependencyGraph;
 import org.apache.maven.graph.GraphBuilder;
 import org.apache.maven.graph.ProjectSelector;
 import org.apache.maven.internal.impl.DefaultSessionFactory;
-import org.apache.maven.internal.impl.InternalSession;
+import org.apache.maven.internal.impl.InternalMavenSession;
 import org.apache.maven.lifecycle.LifecycleExecutionException;
 import org.apache.maven.lifecycle.internal.ExecutionEventCatapult;
 import org.apache.maven.lifecycle.internal.LifecycleStarter;
@@ -218,7 +218,7 @@ public class DefaultMaven implements Maven {
 
             sessionScope.seed(MavenSession.class, session);
             sessionScope.seed(Session.class, session.getSession());
-            sessionScope.seed(InternalSession.class, InternalSession.from(session.getSession()));
+            sessionScope.seed(InternalMavenSession.class, InternalMavenSession.from(session.getSession()));
 
             legacySupport.setSession(session);
 

maven-core/src/main/java/org/apache/maven/execution/MavenSession.java

@@ -32,6 +32,7 @@ import java.util.stream.Collectors;
 import org.apache.maven.api.Session;
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.artifact.repository.RepositoryCache;
+import org.apache.maven.internal.impl.SettingsUtilsV4;
 import org.apache.maven.model.Profile;
 import org.apache.maven.monitor.event.EventDispatcher;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
@@ -41,7 +42,6 @@ import org.apache.maven.settings.Mirror;
 import org.apache.maven.settings.Proxy;
 import org.apache.maven.settings.Server;
 import org.apache.maven.settings.Settings;
-import org.apache.maven.settings.SettingsUtilsV4;
 import org.codehaus.plexus.PlexusContainer;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
 import org.eclipse.aether.RepositorySystemSession;

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultArtifactManager.java

@@ -44,12 +44,12 @@ import static org.apache.maven.internal.impl.Utils.nonNull;
 public class DefaultArtifactManager implements ArtifactManager {
 
     @Nonnull
-    private final InternalSession session;
+    private final InternalMavenSession session;
 
     private final Map<String, Path> paths = new ConcurrentHashMap<>();
 
     @Inject
-    public DefaultArtifactManager(@Nonnull InternalSession session) {
+    public DefaultArtifactManager(@Nonnull InternalMavenSession session) {
         this.session = session;
     }
 

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultEvent.java

@@ -28,10 +28,10 @@ import org.apache.maven.api.Session;
 import org.apache.maven.execution.ExecutionEvent;
 
 public class DefaultEvent implements Event {
-    private final InternalSession session;
+    private final InternalMavenSession session;
     private final ExecutionEvent delegate;
 
-    public DefaultEvent(InternalSession session, ExecutionEvent delegate) {
+    public DefaultEvent(InternalMavenSession session, ExecutionEvent delegate) {
         this.session = session;
         this.delegate = delegate;
     }

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultMojoExecution.java

@@ -41,10 +41,10 @@ import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.eclipse.aether.graph.DependencyNode;
 
 public class DefaultMojoExecution implements MojoExecution {
-    private final InternalSession session;
+    private final InternalMavenSession session;
     private final org.apache.maven.plugin.MojoExecution delegate;
 
-    public DefaultMojoExecution(InternalSession session, org.apache.maven.plugin.MojoExecution delegate) {
+    public DefaultMojoExecution(InternalMavenSession session, org.apache.maven.plugin.MojoExecution delegate) {
         this.session = session;
         this.delegate = delegate;
     }

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultPluginXmlFactory.java

@@ -35,6 +35,8 @@ import org.apache.maven.api.services.xml.*;
 import org.apache.maven.plugin.descriptor.io.PluginDescriptorStaxReader;
 import org.apache.maven.plugin.descriptor.io.PluginDescriptorStaxWriter;
 
+import static org.apache.maven.internal.impl.StaxLocation.getLocation;
+import static org.apache.maven.internal.impl.StaxLocation.getMessage;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -67,7 +69,7 @@ public class DefaultPluginXmlFactory implements PluginXmlFactory {
                 }
             }
         } catch (Exception e) {
-            throw new XmlReaderException("Unable to read model", e);
+            throw new XmlReaderException("Unable to read plugin: " + getMessage(e), getLocation(e), e);
         }
     }
 
@@ -92,7 +94,7 @@ public class DefaultPluginXmlFactory implements PluginXmlFactory {
                 }
             }
         } catch (Exception e) {
-            throw new XmlWriterException("Unable to write model", e);
+            throw new XmlWriterException("Unable to write plugin: " + getMessage(e), getLocation(e), e);
         }
     }
 

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultProject.java

@@ -35,17 +35,17 @@ import static org.apache.maven.internal.impl.Utils.nonNull;
 
 public class DefaultProject implements Project {
 
-    private final InternalSession session;
+    private final InternalMavenSession session;
     private final MavenProject project;
     private final Packaging packaging;
 
-    public DefaultProject(InternalSession session, MavenProject project) {
+    public DefaultProject(InternalMavenSession session, MavenProject project) {
         this.session = session;
         this.project = project;
         this.packaging = session.requirePackaging(project.getPackaging());
     }
 
-    public InternalSession getSession() {
+    public InternalMavenSession getSession() {
         return session;
     }
 

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultProjectBuilder.java

@@ -65,7 +65,7 @@ public class DefaultProjectBuilder implements ProjectBuilder {
     @Override
     public ProjectBuilderResult build(ProjectBuilderRequest request)
             throws ProjectBuilderException, IllegalArgumentException {
-        InternalSession session = InternalSession.from(request.getSession());
+        InternalMavenSession session = InternalMavenSession.from(request.getSession());
         try {
             List<ArtifactRepository> repositories = session.toArtifactRepositories(session.getRemoteRepositories());
             ProjectBuildingRequest req = new DefaultProjectBuildingRequest()

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultProjectManager.java

@@ -44,11 +44,11 @@ import static org.apache.maven.internal.impl.Utils.nonNull;
 @SessionScoped
 public class DefaultProjectManager implements ProjectManager {
 
-    private final InternalSession session;
+    private final InternalMavenSession session;
     private final ArtifactManager artifactManager;
 
     @Inject
-    public DefaultProjectManager(InternalSession session, ArtifactManager artifactManager) {
+    public DefaultProjectManager(InternalMavenSession session, ArtifactManager artifactManager) {
         this.session = session;
         this.artifactManager = artifactManager;
     }
@@ -66,7 +66,7 @@ public class DefaultProjectManager implements ProjectManager {
     @Nonnull
     @Override
     public Collection<Artifact> getAttachedArtifacts(Project project) {
-        InternalSession session = ((DefaultProject) project).getSession();
+        InternalMavenSession session = ((DefaultProject) project).getSession();
         Collection<Artifact> attached = map(
                 getMavenProject(project).getAttachedArtifacts(),
                 a -> session.getArtifact(RepositoryUtils.toArtifact(a)));

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultSession.java

@@ -21,8 +21,6 @@ package org.apache.maven.internal.impl;
 import java.nio.file.Path;
 import java.time.Instant;
 import java.util.*;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Supplier;
 
 import org.apache.maven.RepositoryUtils;
 import org.apache.maven.api.*;
@@ -38,43 +36,39 @@ import org.apache.maven.execution.MavenSession;
 import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
+import org.apache.maven.project.MavenProject;
 import org.apache.maven.rtinfo.RuntimeInformation;
-import org.eclipse.aether.DefaultRepositorySystemSession;
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
 
 import static org.apache.maven.internal.impl.Utils.map;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
-public class DefaultSession extends AbstractSession {
+public class DefaultSession extends AbstractSession implements InternalMavenSession {
 
     private final MavenSession mavenSession;
-    private final RepositorySystemSession session;
-    private final RepositorySystem repositorySystem;
-    private final List<RemoteRepository> repositories;
     private final MavenRepositorySystem mavenRepositorySystem;
-    private final Lookup lookup;
     private final RuntimeInformation runtimeInformation;
-    private final Map<Class<? extends Service>, Service> services = new ConcurrentHashMap<>();
+    private final Map<String, Project> allProjects = Collections.synchronizedMap(new WeakHashMap<>());
 
     @SuppressWarnings("checkstyle:ParameterNumber")
     public DefaultSession(
             @Nonnull MavenSession session,
             @Nonnull RepositorySystem repositorySystem,
-            @Nullable List<RemoteRepository> repositories,
+            @Nullable List<RemoteRepository> remoteRepositories,
             @Nonnull MavenRepositorySystem mavenRepositorySystem,
             @Nonnull Lookup lookup,
             @Nonnull RuntimeInformation runtimeInformation) {
+        super(
+                session.getRepositorySession(),
+                repositorySystem,
+                remoteRepositories,
+                remoteRepositories == null
+                        ? map(session.getRequest().getRemoteRepositories(), RepositoryUtils::toRepo)
+                        : null,
+                lookup);
         this.mavenSession = nonNull(session);
-        this.session = mavenSession.getRepositorySession();
-        this.repositorySystem = nonNull(repositorySystem);
-        this.repositories = repositories != null
-                ? repositories
-                : map(
-                        mavenSession.getRequest().getRemoteRepositories(),
-                        r -> getRemoteRepository(RepositoryUtils.toRepo(r)));
         this.mavenRepositorySystem = mavenRepositorySystem;
-        this.lookup = lookup;
         this.runtimeInformation = runtimeInformation;
     }
 
@@ -82,16 +76,19 @@ public class DefaultSession extends AbstractSession {
         return mavenSession;
     }
 
-    @Nonnull
     @Override
-    public LocalRepository getLocalRepository() {
-        return new DefaultLocalRepository(session.getLocalRepository());
+    public List<Project> getProjects(List<MavenProject> projects) {
+        return projects == null ? null : map(projects, this::getProject);
     }
 
-    @Nonnull
     @Override
-    public List<RemoteRepository> getRemoteRepositories() {
-        return Collections.unmodifiableList(repositories);
+    public Project getProject(MavenProject project) {
+        return allProjects.computeIfAbsent(project.getId(), id -> new DefaultProject(this, project));
+    }
+
+    @Override
+    public List<ArtifactRepository> toArtifactRepositories(List<RemoteRepository> repositories) {
+        return repositories == null ? null : map(repositories, this::toArtifactRepository);
     }
 
     @Nonnull
@@ -171,92 +168,13 @@ public class DefaultSession extends AbstractSession {
         }
     }
 
-    @Nonnull
-    @Override
-    public SessionData getData() {
-        org.eclipse.aether.SessionData data = session.getData();
-        return new SessionData() {
-            @Override
-            public <T> void set(@Nonnull Key<T> key, @Nullable T value) {
-                data.set(key, value);
-            }
-
-            @Override
-            public <T> boolean replace(@Nonnull Key<T> key, @Nullable T oldValue, @Nullable T newValue) {
-                return data.set(key, oldValue, newValue);
-            }
-
-            @Nullable
-            @Override
-            @SuppressWarnings("unchecked")
-            public <T> T get(@Nonnull Key<T> key) {
-                return (T) data.get(key);
-            }
-
-            @Nullable
-            @Override
-            @SuppressWarnings("unchecked")
-            public <T> T computeIfAbsent(@Nonnull Key<T> key, @Nonnull Supplier<T> supplier) {
-                return (T) data.computeIfAbsent(key, (Supplier<Object>) supplier);
-            }
-        };
-    }
-
-    @Nonnull
-    @Override
-    public Session withLocalRepository(@Nonnull LocalRepository localRepository) {
-        nonNull(localRepository, "localRepository");
-        if (session.getLocalRepository() != null
-                && Objects.equals(session.getLocalRepository().getBasedir().toPath(), localRepository.getPath())) {
-            return this;
+    protected Session newSession(RepositorySystemSession repoSession, List<RemoteRepository> repositories) {
+        MavenSession ms = this.mavenSession;
+        if (repoSession != this.getSession()) {
+            ms = new MavenSession(repoSession, ms.getRequest(), ms.getResult());
         }
-        org.eclipse.aether.repository.LocalRepository repository = toRepository(localRepository);
-        org.eclipse.aether.repository.LocalRepositoryManager localRepositoryManager =
-                repositorySystem.newLocalRepositoryManager(session, repository);
-
-        RepositorySystemSession repoSession =
-                new DefaultRepositorySystemSession(session).setLocalRepositoryManager(localRepositoryManager);
-        MavenSession newSession = new MavenSession(repoSession, mavenSession.getRequest(), mavenSession.getResult());
         return new DefaultSession(
-                newSession, repositorySystem, repositories, mavenRepositorySystem, lookup, runtimeInformation);
-    }
-
-    @Nonnull
-    @Override
-    public Session withRemoteRepositories(@Nonnull List<RemoteRepository> repositories) {
-        return new DefaultSession(
-                mavenSession, repositorySystem, repositories, mavenRepositorySystem, lookup, runtimeInformation);
-    }
-
-    @Nonnull
-    @Override
-    @SuppressWarnings("unchecked")
-    public <T extends Service> T getService(Class<T> clazz) throws NoSuchElementException {
-        T t = (T) services.computeIfAbsent(clazz, this::lookup);
-        if (t == null) {
-            throw new NoSuchElementException(clazz.getName());
-        }
-        return t;
-    }
-
-    private Service lookup(Class<? extends Service> c) {
-        try {
-            return lookup.lookup(c);
-        } catch (LookupException e) {
-            NoSuchElementException nsee = new NoSuchElementException(c.getName());
-            e.initCause(e);
-            throw nsee;
-        }
-    }
-
-    @Nonnull
-    public RepositorySystemSession getSession() {
-        return session;
-    }
-
-    @Nonnull
-    public RepositorySystem getRepositorySystem() {
-        return repositorySystem;
+                ms, getRepositorySystem(), repositories, mavenRepositorySystem, lookup, runtimeInformation);
     }
 
     public ArtifactRepository toArtifactRepository(RemoteRepository repository) {
@@ -281,25 +199,4 @@ public class DefaultSession extends AbstractSession {
             throw new UnsupportedOperationException("Not yet implemented");
         }
     }
-
-    public org.eclipse.aether.graph.Dependency toDependency(DependencyCoordinate dependency, boolean managed) {
-        org.eclipse.aether.graph.Dependency dep;
-        if (dependency instanceof DefaultDependencyCoordinate) {
-            dep = ((DefaultDependencyCoordinate) dependency).getDependency();
-        } else {
-            dep = new org.eclipse.aether.graph.Dependency(
-                    new org.eclipse.aether.artifact.DefaultArtifact(
-                            dependency.getGroupId(),
-                            dependency.getArtifactId(),
-                            dependency.getClassifier(),
-                            dependency.getType().getExtension(),
-                            dependency.getVersion().toString(),
-                            null),
-                    dependency.getScope().id());
-        }
-        if (!managed && "".equals(dep.getScope())) {
-            dep = dep.setScope(DependencyScope.COMPILE.id());
-        }
-        return dep;
-    }
 }

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultSessionFactory.java

@@ -53,7 +53,7 @@ public class DefaultSessionFactory {
 
     public Session getSession(MavenSession mavenSession) {
         SessionData data = mavenSession.getRepositorySession().getData();
-        return (Session) data.computeIfAbsent(InternalSession.class, () -> newSession(mavenSession));
+        return (Session) data.computeIfAbsent(InternalMavenSession.class, () -> newSession(mavenSession));
     }
 
     private Session newSession(MavenSession mavenSession) {

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultSettingsBuilder.java

@@ -1,162 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.apache.maven.internal.impl;
-
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.List;
-import java.util.Map;
-import java.util.Properties;
-
-import org.apache.maven.api.annotations.Nonnull;
-import org.apache.maven.api.services.BuilderProblem;
-import org.apache.maven.api.services.SettingsBuilder;
-import org.apache.maven.api.services.SettingsBuilderException;
-import org.apache.maven.api.services.SettingsBuilderRequest;
-import org.apache.maven.api.services.SettingsBuilderResult;
-import org.apache.maven.api.services.Source;
-import org.apache.maven.api.settings.Settings;
-import org.apache.maven.settings.building.DefaultSettingsBuildingRequest;
-import org.apache.maven.settings.building.SettingsBuildingException;
-import org.apache.maven.settings.building.SettingsBuildingResult;
-import org.apache.maven.settings.building.SettingsProblem;
-import org.apache.maven.settings.building.SettingsSource;
-
-@Named
-@Singleton
-public class DefaultSettingsBuilder implements SettingsBuilder {
-
-    private final org.apache.maven.settings.building.SettingsBuilder builder;
-
-    @Inject
-    public DefaultSettingsBuilder(org.apache.maven.settings.building.SettingsBuilder builder) {
-        this.builder = builder;
-    }
-
-    @Nonnull
-    @Override
-    public SettingsBuilderResult build(SettingsBuilderRequest request)
-            throws SettingsBuilderException, IllegalArgumentException {
-        InternalSession session = InternalSession.from(request.getSession());
-        try {
-            DefaultSettingsBuildingRequest req = new DefaultSettingsBuildingRequest();
-            req.setUserProperties(toProperties(session.getUserProperties()));
-            req.setSystemProperties(toProperties(session.getSystemProperties()));
-            if (request.getGlobalSettingsSource().isPresent()) {
-                req.setGlobalSettingsSource(new MappedSettingsSource(
-                        request.getGlobalSettingsSource().get()));
-            }
-            if (request.getGlobalSettingsPath().isPresent()) {
-                req.setGlobalSettingsFile(request.getGlobalSettingsPath().get().toFile());
-            }
-            if (request.getUserSettingsSource().isPresent()) {
-                req.setUserSettingsSource(
-                        new MappedSettingsSource(request.getUserSettingsSource().get()));
-            }
-            if (request.getUserSettingsPath().isPresent()) {
-                req.setUserSettingsFile(request.getUserSettingsPath().get().toFile());
-            }
-            SettingsBuildingResult result = builder.build(req);
-            return new SettingsBuilderResult() {
-                @Override
-                public Settings getEffectiveSettings() {
-                    return result.getEffectiveSettings().getDelegate();
-                }
-
-                @Override
-                public List<BuilderProblem> getProblems() {
-                    return new MappedList<>(result.getProblems(), MappedBuilderProblem::new);
-                }
-            };
-        } catch (SettingsBuildingException e) {
-            throw new SettingsBuilderException("Unable to build settings", e);
-        }
-    }
-
-    private Properties toProperties(Map<String, String> map) {
-        Properties properties = new Properties();
-        properties.putAll(map);
-        return properties;
-    }
-
-    private static class MappedSettingsSource implements SettingsSource {
-        private final Source source;
-
-        MappedSettingsSource(Source source) {
-            this.source = source;
-        }
-
-        @Override
-        public InputStream getInputStream() throws IOException {
-            return source.openStream();
-        }
-
-        @Override
-        public String getLocation() {
-            return source.getLocation();
-        }
-    }
-
-    private static class MappedBuilderProblem implements BuilderProblem {
-        private final SettingsProblem problem;
-
-        MappedBuilderProblem(SettingsProblem problem) {
-            this.problem = problem;
-        }
-
-        @Override
-        public String getSource() {
-            return problem.getSource();
-        }
-
-        @Override
-        public int getLineNumber() {
-            return problem.getLineNumber();
-        }
-
-        @Override
-        public int getColumnNumber() {
-            return problem.getColumnNumber();
-        }
-
-        @Override
-        public String getLocation() {
-            return problem.getLocation();
-        }
-
-        @Override
-        public Exception getException() {
-            return problem.getException();
-        }
-
-        @Override
-        public String getMessage() {
-            return problem.getMessage();
-        }
-
-        @Override
-        public Severity getSeverity() {
-            return Severity.valueOf(problem.getSeverity().name());
-        }
-    }
-}

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultToolchainManager.java

@@ -49,7 +49,7 @@ public class DefaultToolchainManager implements ToolchainManager {
     @Override
     public List<Toolchain> getToolchains(Session session, String type, Map<String, String> requirements)
             throws ToolchainManagerException {
-        MavenSession s = InternalSession.from(session).getMavenSession();
+        MavenSession s = InternalMavenSession.from(session).getMavenSession();
         List<org.apache.maven.toolchain.Toolchain> toolchains =
                 toolchainManagerPrivate.getToolchains(s, type, requirements);
         return new MappedList<>(toolchains, this::toToolchain);
@@ -58,7 +58,7 @@ public class DefaultToolchainManager implements ToolchainManager {
     @Override
     public Optional<Toolchain> getToolchainFromBuildContext(Session session, String type)
             throws ToolchainManagerException {
-        MavenSession s = InternalSession.from(session).getMavenSession();
+        MavenSession s = InternalMavenSession.from(session).getMavenSession();
         return Optional.ofNullable(toolchainManagerPrivate.getToolchainFromBuildContext(type, s))
                 .map(this::toToolchain);
     }
@@ -66,7 +66,7 @@ public class DefaultToolchainManager implements ToolchainManager {
     @Override
     public List<Toolchain> getToolchainsForType(Session session, String type) throws ToolchainManagerException {
         try {
-            MavenSession s = InternalSession.from(session).getMavenSession();
+            MavenSession s = InternalMavenSession.from(session).getMavenSession();
             ToolchainPrivate[] toolchains = toolchainManagerPrivate.getToolchainsForType(type, s);
             return new MappedList<>(Arrays.asList(toolchains), this::toToolchain);
         } catch (MisconfiguredToolchainException e) {
@@ -76,7 +76,7 @@ public class DefaultToolchainManager implements ToolchainManager {
 
     @Override
     public void storeToolchainToBuildContext(Session session, Toolchain toolchain) throws ToolchainManagerException {
-        MavenSession s = InternalSession.from(session).getMavenSession();
+        MavenSession s = InternalMavenSession.from(session).getMavenSession();
         org.apache.maven.toolchain.ToolchainPrivate tc =
                 (org.apache.maven.toolchain.ToolchainPrivate) ((ToolchainWrapper) toolchain).toolchain;
         toolchainManagerPrivate.storeToolchainToBuildContext(tc, s);

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultToolchainsBuilder.java

@@ -1,149 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.apache.maven.internal.impl;
-
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.List;
-
-import org.apache.maven.api.annotations.Nonnull;
-import org.apache.maven.api.services.BuilderProblem;
-import org.apache.maven.api.services.Source;
-import org.apache.maven.api.services.ToolchainsBuilder;
-import org.apache.maven.api.services.ToolchainsBuilderException;
-import org.apache.maven.api.services.ToolchainsBuilderRequest;
-import org.apache.maven.api.services.ToolchainsBuilderResult;
-import org.apache.maven.api.toolchain.PersistedToolchains;
-import org.apache.maven.toolchain.building.DefaultToolchainsBuildingRequest;
-import org.apache.maven.toolchain.building.ToolchainsBuildingException;
-import org.apache.maven.toolchain.building.ToolchainsBuildingResult;
-
-@Named
-@Singleton
-public class DefaultToolchainsBuilder implements ToolchainsBuilder {
-
-    private final org.apache.maven.toolchain.building.ToolchainsBuilder builder;
-
-    @Inject
-    public DefaultToolchainsBuilder(org.apache.maven.toolchain.building.ToolchainsBuilder builder) {
-        this.builder = builder;
-    }
-
-    @Nonnull
-    @Override
-    public ToolchainsBuilderResult build(ToolchainsBuilderRequest request)
-            throws ToolchainsBuilderException, IllegalArgumentException {
-        try {
-            DefaultToolchainsBuildingRequest req = new DefaultToolchainsBuildingRequest();
-            if (request.getGlobalToolchainsSource().isPresent()) {
-                req.setGlobalToolchainsSource(new MappedToolchainsSource(
-                        request.getGlobalToolchainsSource().get()));
-            } else if (request.getGlobalToolchainsPath().isPresent()) {
-                req.setGlobalToolchainsSource(new org.apache.maven.building.FileSource(
-                        request.getGlobalToolchainsPath().get().toFile()));
-            }
-            if (request.getUserToolchainsSource().isPresent()) {
-                req.setUserToolchainsSource(new MappedToolchainsSource(
-                        request.getUserToolchainsSource().get()));
-            } else if (request.getUserToolchainsPath().isPresent()) {
-                req.setUserToolchainsSource(new org.apache.maven.building.FileSource(
-                        request.getUserToolchainsPath().get().toFile()));
-            }
-            ToolchainsBuildingResult result = builder.build(req);
-            return new ToolchainsBuilderResult() {
-                @Override
-                public PersistedToolchains getEffectiveToolchains() {
-                    return result.getEffectiveToolchains().getDelegate();
-                }
-
-                @Override
-                public List<BuilderProblem> getProblems() {
-                    return new MappedList<>(result.getProblems(), MappedBuilderProblem::new);
-                }
-            };
-        } catch (ToolchainsBuildingException e) {
-            throw new ToolchainsBuilderException("Unable to build Toolchains", e);
-        }
-    }
-
-    private static class MappedToolchainsSource implements org.apache.maven.building.Source {
-        private final Source source;
-
-        MappedToolchainsSource(Source source) {
-            this.source = source;
-        }
-
-        @Override
-        public InputStream getInputStream() throws IOException {
-            return source.openStream();
-        }
-
-        @Override
-        public String getLocation() {
-            return source.getLocation();
-        }
-    }
-
-    private static class MappedBuilderProblem implements BuilderProblem {
-        private final org.apache.maven.building.Problem problem;
-
-        MappedBuilderProblem(org.apache.maven.building.Problem problem) {
-            this.problem = problem;
-        }
-
-        @Override
-        public String getSource() {
-            return problem.getSource();
-        }
-
-        @Override
-        public int getLineNumber() {
-            return problem.getLineNumber();
-        }
-
-        @Override
-        public int getColumnNumber() {
-            return problem.getColumnNumber();
-        }
-
-        @Override
-        public String getLocation() {
-            return problem.getLocation();
-        }
-
-        @Override
-        public Exception getException() {
-            return problem.getException();
-        }
-
-        @Override
-        public String getMessage() {
-            return problem.getMessage();
-        }
-
-        @Override
-        public Severity getSeverity() {
-            return Severity.valueOf(problem.getSeverity().name());
-        }
-    }
-}

maven-core/src/main/java/org/apache/maven/internal/impl/EventSpyImpl.java

@@ -47,7 +47,7 @@ public class EventSpyImpl implements EventSpy {
     public void onEvent(Object arg) throws Exception {
         if (arg instanceof ExecutionEvent) {
             ExecutionEvent ee = (ExecutionEvent) arg;
-            InternalSession session = InternalSession.from(sessionFactory.getSession(ee.getSession()));
+            InternalMavenSession session = InternalMavenSession.from(sessionFactory.getSession(ee.getSession()));
             Collection<Listener> listeners = session.getListeners();
             if (!listeners.isEmpty()) {
                 Event event = new DefaultEvent(session, ee);

maven-core/src/main/java/org/apache/maven/internal/impl/InternalMavenSession.java

@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import java.util.List;
+
+import org.apache.maven.api.Project;
+import org.apache.maven.api.RemoteRepository;
+import org.apache.maven.api.Session;
+import org.apache.maven.execution.MavenSession;
+
+import static org.apache.maven.internal.impl.Utils.cast;
+
+public interface InternalMavenSession extends InternalSession {
+
+    static InternalMavenSession from(Session session) {
+        return cast(InternalMavenSession.class, session, "session should be an " + InternalMavenSession.class);
+    }
+
+    List<Project> getProjects(List<org.apache.maven.project.MavenProject> projects);
+
+    Project getProject(org.apache.maven.project.MavenProject project);
+
+    List<org.apache.maven.artifact.repository.ArtifactRepository> toArtifactRepositories(
+            List<RemoteRepository> repositories);
+
+    org.apache.maven.artifact.repository.ArtifactRepository toArtifactRepository(RemoteRepository repository);
+
+    MavenSession getMavenSession();
+}

maven-core/src/main/java/org/apache/maven/internal/impl/SisuDiBridgeModule.java

@@ -0,0 +1,89 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.internal.impl;
+
+import javax.inject.Named;
+import javax.inject.Provider;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Stream;
+
+import com.google.inject.AbstractModule;
+import org.apache.maven.di.Injector;
+import org.apache.maven.di.Key;
+import org.apache.maven.di.impl.Binding;
+import org.apache.maven.di.impl.InjectorImpl;
+import org.codehaus.plexus.PlexusContainer;
+
+@Named
+class SisuDiBridgeModule extends AbstractModule {
+
+    @Override
+    protected void configure() {
+        Provider<PlexusContainer> containerProvider = getProvider(PlexusContainer.class);
+
+        Injector injector = new InjectorImpl() {
+            @Override
+            protected <T> Set<Binding<T>> getBindings(Key<T> key) {
+                Set<Binding<T>> bindings = super.getBindings(key);
+                if (bindings == null && key.getRawType() != List.class && key.getRawType() != Map.class) {
+                    try {
+                        T t = containerProvider.get().lookup(key.getRawType());
+                        bindings = Set.of(new Binding.BindingToInstance<>(t));
+                    } catch (Throwable e) {
+                        // ignore
+                        e.printStackTrace();
+                    }
+                }
+                return bindings;
+            }
+        };
+        injector.bindInstance(Injector.class, injector);
+        bind(Injector.class).toInstance(injector);
+
+        Stream.of(
+                        DefaultArtifactCoordinateFactory.class,
+                        DefaultArtifactDeployer.class,
+                        DefaultArtifactFactory.class,
+                        DefaultArtifactInstaller.class,
+                        DefaultArtifactResolver.class,
+                        DefaultChecksumAlgorithmService.class,
+                        DefaultDependencyCollector.class,
+                        DefaultDependencyCoordinateFactory.class,
+                        DefaultLocalRepositoryManager.class,
+                        DefaultMessageBuilderFactory.class,
+                        DefaultModelXmlFactory.class,
+                        DefaultRepositoryFactory.class,
+                        DefaultSettingsBuilder.class,
+                        DefaultSettingsXmlFactory.class,
+                        DefaultToolchainsBuilder.class,
+                        DefaultToolchainsXmlFactory.class,
+                        DefaultTransportProvider.class,
+                        DefaultVersionParser.class,
+                        DefaultVersionRangeResolver.class,
+                        DefaultVersionResolver.class)
+                .forEach((Class<?> clazz) -> {
+                    injector.bindImplicit(clazz);
+                    Class<Object> itf = (Class) clazz.getInterfaces()[0];
+                    bind(itf).toProvider(() -> injector.getInstance(clazz));
+                });
+    }
+}

maven-core/src/main/java/org/apache/maven/plugin/DefaultBuildPluginManager.java

@@ -34,7 +34,7 @@ import org.apache.maven.execution.MojoExecutionListener;
 import org.apache.maven.execution.scope.internal.MojoExecutionScope;
 import org.apache.maven.internal.impl.DefaultLog;
 import org.apache.maven.internal.impl.DefaultMojoExecution;
-import org.apache.maven.internal.impl.InternalSession;
+import org.apache.maven.internal.impl.InternalMavenSession;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
@@ -121,7 +121,7 @@ public class DefaultBuildPluginManager implements BuildPluginManager {
                     org.apache.maven.api.plugin.Log.class,
                     new DefaultLog(LoggerFactory.getLogger(
                             mojoExecution.getMojoDescriptor().getFullGoalName())));
-            InternalSession sessionV4 = InternalSession.from(session.getSession());
+            InternalMavenSession sessionV4 = InternalMavenSession.from(session.getSession());
             scope.seed(Project.class, sessionV4.getProject(project));
             scope.seed(org.apache.maven.api.MojoExecution.class, new DefaultMojoExecution(sessionV4, mojoExecution));
 

maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultMavenPluginManager.java

@@ -44,7 +44,7 @@ import org.apache.maven.execution.scope.internal.MojoExecutionScope;
 import org.apache.maven.execution.scope.internal.MojoExecutionScopeModule;
 import org.apache.maven.internal.impl.DefaultLog;
 import org.apache.maven.internal.impl.DefaultMojoExecution;
-import org.apache.maven.internal.impl.InternalSession;
+import org.apache.maven.internal.impl.InternalMavenSession;
 import org.apache.maven.internal.xml.XmlPlexusConfiguration;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.ContextEnabled;
@@ -522,12 +522,12 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
             throws PluginContainerException, PluginConfigurationException {
         T mojo;
 
-        InternalSession sessionV4 = InternalSession.from(session.getSession());
+        InternalMavenSession sessionV4 = InternalMavenSession.from(session.getSession());
         Project project = sessionV4.getProject(session.getCurrentProject());
 
         List<org.apache.maven.api.RemoteRepository> repos =
                 sessionV4.getService(ProjectManager.class).getRemoteProjectRepositories(project);
-        sessionV4 = InternalSession.from(sessionV4.withRemoteRepositories(repos));
+        sessionV4 = InternalMavenSession.from(sessionV4.withRemoteRepositories(repos));
 
         org.apache.maven.api.MojoExecution execution = new DefaultMojoExecution(sessionV4, mojoExecution);
         org.apache.maven.api.plugin.Log log = new DefaultLog(
@@ -665,7 +665,7 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
             pomConfiguration = XmlPlexusConfiguration.toPlexusConfiguration(dom);
         }
 
-        InternalSession sessionV4 = InternalSession.from(session.getSession());
+        InternalMavenSession sessionV4 = InternalMavenSession.from(session.getSession());
         ExpressionEvaluator expressionEvaluator = new PluginParameterExpressionEvaluator(session, mojoExecution);
 
         for (MavenPluginConfigurationValidator validator : configurationValidators) {

maven-core/src/main/java/org/apache/maven/project/DefaultProjectBuilder.java

@@ -38,7 +38,7 @@ import org.apache.maven.artifact.InvalidArtifactRTException;
 import org.apache.maven.artifact.InvalidRepositoryException;
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.bridge.MavenRepositorySystem;
-import org.apache.maven.internal.impl.InternalSession;
+import org.apache.maven.internal.impl.InternalMavenSession;
 import org.apache.maven.model.Build;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.model.DependencyManagement;
@@ -909,7 +909,8 @@ public class DefaultProjectBuilder implements ProjectBuilder {
                 modelBuildingRequest.setModelCache(modelCacheFactory.createCache(session));
             }
             modelBuildingRequest.setTransformerContextBuilder(transformerContextBuilder);
-            InternalSession session = (InternalSession) this.session.getData().get(InternalSession.class);
+            InternalMavenSession session =
+                    (InternalMavenSession) this.session.getData().get(InternalMavenSession.class);
             if (session != null) {
                 try {
                     modelBuildingRequest.setRootDirectory(session.getRootDirectory());

maven-core/src/main/java/org/apache/maven/project/ExtensionDescriptorBuilder.java

@@ -32,7 +32,7 @@ import java.util.zip.ZipEntry;
 
 import com.ctc.wstx.stax.WstxInputFactory;
 import org.apache.maven.api.xml.XmlNode;
-import org.apache.maven.internal.xml.XmlNodeBuilder;
+import org.apache.maven.internal.xml.XmlNodeStaxBuilder;
 
 /**
  * Creates an extension descriptor from some XML stream.
@@ -89,7 +89,7 @@ public class ExtensionDescriptorBuilder {
         XmlNode dom;
         try {
             XMLStreamReader reader = WstxInputFactory.newFactory().createXMLStreamReader(is);
-            dom = XmlNodeBuilder.build(reader);
+            dom = XmlNodeStaxBuilder.build(reader);
         } catch (XMLStreamException e) {
             throw new IOException(e.getMessage(), e);
         }

maven-core/src/main/java/org/apache/maven/session/scope/internal/SessionScopeModule.java

@@ -25,7 +25,7 @@ import com.google.inject.AbstractModule;
 import org.apache.maven.SessionScoped;
 import org.apache.maven.api.Session;
 import org.apache.maven.execution.MavenSession;
-import org.apache.maven.internal.impl.InternalSession;
+import org.apache.maven.internal.impl.InternalMavenSession;
 
 /**
  * SessionScopeModule
@@ -55,8 +55,8 @@ public class SessionScopeModule extends AbstractModule {
         bind(Session.class)
                 .toProvider(SessionScope.seededKeyProvider(Session.class))
                 .in(scope);
-        bind(InternalSession.class)
-                .toProvider(SessionScope.seededKeyProvider(InternalSession.class))
+        bind(InternalMavenSession.class)
+                .toProvider(SessionScope.seededKeyProvider(InternalMavenSession.class))
                 .in(scope);
     }
 }

maven-core/src/main/java/org/apache/maven/settings/SettingsUtils.java

@@ -18,6 +18,8 @@
  */
 package org.apache.maven.settings;
 
+import org.apache.maven.internal.impl.SettingsUtilsV4;
+
 /**
  * Several convenience methods to handle settings
  *

maven-core/src/test/java/org/apache/maven/configuration/DefaultBeanConfiguratorPathTest.java

@@ -26,7 +26,7 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 
 import org.apache.maven.configuration.internal.DefaultBeanConfigurator;
-import org.apache.maven.internal.xml.XmlNodeBuilder;
+import org.apache.maven.internal.xml.XmlNodeStaxBuilder;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -52,9 +52,9 @@ class DefaultBeanConfiguratorPathTest {
 
     private Xpp3Dom toConfig(String xml) {
         try {
-            return new Xpp3Dom(XmlNodeBuilder.build(
+            return new Xpp3Dom(XmlNodeStaxBuilder.build(
                     new StringReader("<configuration>" + xml + "</configuration>"),
-                    (XmlNodeBuilder.InputLocationBuilderStax) null));
+                    (XmlNodeStaxBuilder.InputLocationBuilderStax) null));
         } catch (XMLStreamException e) {
             throw new IllegalArgumentException(e);
         }

maven-core/src/test/java/org/apache/maven/configuration/DefaultBeanConfiguratorTest.java

@@ -24,7 +24,7 @@ import java.io.File;
 import java.io.StringReader;
 
 import org.apache.maven.configuration.internal.DefaultBeanConfigurator;
-import org.apache.maven.internal.xml.XmlNodeBuilder;
+import org.apache.maven.internal.xml.XmlNodeStaxBuilder;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -50,9 +50,9 @@ class DefaultBeanConfiguratorTest {
 
     private Xpp3Dom toConfig(String xml) {
         try {
-            return new Xpp3Dom(XmlNodeBuilder.build(
+            return new Xpp3Dom(XmlNodeStaxBuilder.build(
                     new StringReader("<configuration>" + xml + "</configuration>"),
-                    (XmlNodeBuilder.InputLocationBuilderStax) null));
+                    (XmlNodeStaxBuilder.InputLocationBuilderStax) null));
         } catch (XMLStreamException e) {
             throw new IllegalArgumentException(e);
         }

maven-core/src/test/java/org/apache/maven/internal/impl/TestApi.java

@@ -125,7 +125,7 @@ class TestApi {
                 .withRemoteRepositories(Collections.singletonList(remoteRepository));
 
         sessionScope.enter();
-        sessionScope.seed(InternalSession.class, InternalSession.from(this.session));
+        sessionScope.seed(InternalMavenSession.class, InternalMavenSession.from(this.session));
     }
 
     private Project project(Artifact artifact) {

maven-core/src/test/java/org/apache/maven/plugin/PluginParameterExpressionEvaluatorV4Test.java

@@ -413,7 +413,8 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
         pd.addComponentDescriptor(md);
 
-        return new DefaultMojoExecution((AbstractSession) session, new org.apache.maven.plugin.MojoExecution(md));
+        return new DefaultMojoExecution(
+                InternalMavenSession.from(session), new org.apache.maven.plugin.MojoExecution(md));
     }
 
     private DefaultSession newSession() throws Exception {

maven-core/src/test/java/org/apache/maven/settings/SettingsUtilsTest.java

@@ -32,6 +32,7 @@ import org.apache.maven.api.settings.ActivationProperty;
 import org.apache.maven.api.settings.Profile;
 import org.apache.maven.api.settings.Repository;
 import org.apache.maven.api.settings.Settings;
+import org.apache.maven.internal.impl.SettingsUtilsV4;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;

maven-di/src/main/java/org/apache/maven/di/impl/Binding.java

@@ -143,7 +143,7 @@ public abstract class Binding<T> {
     public static class BindingToInstance<T> extends Binding<T> {
         final T instance;
 
-        BindingToInstance(T instance) {
+        public BindingToInstance(T instance) {
             super(null, Collections.emptySet());
             this.instance = instance;
         }

maven-di/src/main/java/org/apache/maven/di/impl/InjectorImpl.java

@@ -130,7 +130,7 @@ public class InjectorImpl implements Injector {
     }
 
     @SuppressWarnings({"unchecked", "rawtypes"})
-    private <T> Set<Binding<T>> getBindings(Key<T> key) {
+    protected <T> Set<Binding<T>> getBindings(Key<T> key) {
         return (Set) bindings.get(key);
     }
 

maven-plugin-api/src/main/java/org/apache/maven/plugin/descriptor/PluginDescriptorBuilder.java

@@ -32,7 +32,7 @@ import java.util.Optional;
 
 import com.ctc.wstx.stax.WstxInputFactory;
 import org.apache.maven.api.xml.XmlNode;
-import org.apache.maven.internal.xml.XmlNodeBuilder;
+import org.apache.maven.internal.xml.XmlNodeStaxBuilder;
 import org.apache.maven.internal.xml.XmlPlexusConfiguration;
 import org.apache.maven.plugin.descriptor.io.PluginDescriptorStaxReader;
 import org.codehaus.plexus.component.repository.ComponentDependency;
@@ -142,7 +142,7 @@ public class PluginDescriptorBuilder {
                     new PluginDescriptorStaxReader().read(xsr, true);
             return new PluginDescriptor(pd);
         } else {
-            XmlNode node = XmlNodeBuilder.build(xsr, true, null);
+            XmlNode node = XmlNodeStaxBuilder.build(xsr, true, null);
             PlexusConfiguration cfg = XmlPlexusConfiguration.toPlexusConfiguration(node);
             return build(source, cfg);
         }
@@ -474,7 +474,7 @@ public class PluginDescriptorBuilder {
     public PlexusConfiguration buildConfiguration(Reader configuration) throws PlexusConfigurationException {
         try {
             XMLStreamReader reader = WstxInputFactory.newFactory().createXMLStreamReader(configuration);
-            return XmlPlexusConfiguration.toPlexusConfiguration(XmlNodeBuilder.build(reader, true, null));
+            return XmlPlexusConfiguration.toPlexusConfiguration(XmlNodeStaxBuilder.build(reader, true, null));
         } catch (XMLStreamException e) {
             throw new PlexusConfigurationException(e.getMessage(), e);
         }
@@ -483,7 +483,7 @@ public class PluginDescriptorBuilder {
     public PlexusConfiguration buildConfiguration(InputStream configuration) throws PlexusConfigurationException {
         try {
             XMLStreamReader reader = WstxInputFactory.newFactory().createXMLStreamReader(configuration);
-            return XmlPlexusConfiguration.toPlexusConfiguration(XmlNodeBuilder.build(reader, true, null));
+            return XmlPlexusConfiguration.toPlexusConfiguration(XmlNodeStaxBuilder.build(reader, true, null));
         } catch (XMLStreamException e) {
             throw new PlexusConfigurationException(e.getMessage(), e);
         }

maven-settings-builder/pom.xml

@@ -38,6 +38,10 @@ under the License.
   </contributors>
 
   <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-impl</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-builder-support</artifactId>
@@ -79,6 +83,11 @@ under the License.
           <parameter>
             <excludes>
               <exclude>org.apache.maven.settings.validation.SettingsValidator#validate(org.apache.maven.settings.Settings,boolean,org.apache.maven.settings.building.SettingsProblemCollector):METHOD_NEW_DEFAULT</exclude>
+              <exclude>org.apache.maven.settings.building.DefaultSettingsBuilder#setSettingsReader(org.apache.maven.settings.io.SettingsReader):METHOD_REMOVED</exclude>
+              <exclude>org.apache.maven.settings.building.DefaultSettingsBuilder#setSettingsValidator(org.apache.maven.settings.validation.SettingsValidator):METHOD_REMOVED</exclude>
+              <exclude>org.apache.maven.settings.building.DefaultSettingsBuilder#setSettingsWriter(org.apache.maven.settings.io.SettingsWriter):METHOD_REMOVED</exclude>
+              <exclude>org.apache.maven.settings.building.DefaultSettingsBuilder#DefaultSettingsBuilder(org.apache.maven.settings.io.SettingsReader,org.apache.maven.settings.io.SettingsWriter,org.apache.maven.settings.validation.SettingsValidator):CONSTRUCTOR_REMOVED</exclude>
+              <exclude>org.apache.maven.settings.validation.DefaultSettingsValidator#DefaultSettingsValidator():CONSTRUCTOR_REMOVED</exclude>
             </excludes>
           </parameter>
         </configuration>

maven-settings-builder/src/main/java/org/apache/maven/settings/building/DefaultSettingsBuilder.java

@@ -24,29 +24,21 @@ import javax.inject.Singleton;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
+import java.io.InputStream;
+import java.lang.reflect.Method;
+import java.nio.file.Path;
 import java.util.List;
-import java.util.Map;
+import java.util.stream.Collectors;
 
-import org.apache.maven.api.settings.InputSource;
+import org.apache.maven.api.Session;
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.services.SettingsBuilderException;
+import org.apache.maven.api.services.SettingsBuilderRequest;
+import org.apache.maven.api.services.SettingsBuilderResult;
+import org.apache.maven.api.services.xml.SettingsXmlFactory;
 import org.apache.maven.building.FileSource;
 import org.apache.maven.building.Source;
-import org.apache.maven.settings.Repository;
-import org.apache.maven.settings.RepositoryPolicy;
-import org.apache.maven.settings.Server;
 import org.apache.maven.settings.Settings;
-import org.apache.maven.settings.TrackableBase;
-import org.apache.maven.settings.io.SettingsParseException;
-import org.apache.maven.settings.io.SettingsReader;
-import org.apache.maven.settings.io.SettingsWriter;
-import org.apache.maven.settings.merge.MavenSettingsMerger;
-import org.apache.maven.settings.v4.SettingsTransformer;
-import org.apache.maven.settings.validation.SettingsValidator;
-import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
-import org.codehaus.plexus.interpolation.InterpolationException;
-import org.codehaus.plexus.interpolation.PropertiesBasedValueSource;
-import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
 
 /**
  * Builds the effective settings from a user settings file and/or a global settings file.
@@ -56,215 +48,99 @@ import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
 @Singleton
 public class DefaultSettingsBuilder implements SettingsBuilder {
 
-    private SettingsReader settingsReader;
-
-    private SettingsWriter settingsWriter;
-
-    private SettingsValidator settingsValidator;
-
-    private final MavenSettingsMerger settingsMerger = new MavenSettingsMerger();
+    private final org.apache.maven.internal.impl.DefaultSettingsBuilder builder;
+    private final org.apache.maven.internal.impl.DefaultSettingsXmlFactory settingsXmlFactory;
 
     @Inject
     public DefaultSettingsBuilder(
-            SettingsReader settingsReader, SettingsWriter settingsWriter, SettingsValidator settingsValidator) {
-        this.settingsReader = settingsReader;
-        this.settingsWriter = settingsWriter;
-        this.settingsValidator = settingsValidator;
-    }
-
-    public DefaultSettingsBuilder setSettingsReader(SettingsReader settingsReader) {
-        this.settingsReader = settingsReader;
-        return this;
-    }
-
-    public DefaultSettingsBuilder setSettingsWriter(SettingsWriter settingsWriter) {
-        this.settingsWriter = settingsWriter;
-        return this;
-    }
-
-    public DefaultSettingsBuilder setSettingsValidator(SettingsValidator settingsValidator) {
-        this.settingsValidator = settingsValidator;
-        return this;
+            org.apache.maven.internal.impl.DefaultSettingsBuilder builder,
+            org.apache.maven.internal.impl.DefaultSettingsXmlFactory settingsXmlFactory) {
+        this.builder = builder;
+        this.settingsXmlFactory = settingsXmlFactory;
     }
 
     @Override
     public SettingsBuildingResult build(SettingsBuildingRequest request) throws SettingsBuildingException {
-        DefaultSettingsProblemCollector problems = new DefaultSettingsProblemCollector(null);
 
-        Source globalSettingsSource =
-                getSettingsSource(request.getGlobalSettingsFile(), request.getGlobalSettingsSource());
-        Settings globalSettings = readSettings(globalSettingsSource, false, request, problems);
+        try {
+            SettingsBuilderResult result = builder.build(SettingsBuilderRequest.builder()
+                    .session((Session) java.lang.reflect.Proxy.newProxyInstance(
+                            Session.class.getClassLoader(),
+                            new Class[] {Session.class},
+                            (Object proxy, Method method, Object[] args) -> {
+                                if ("getSystemProperties".equals(method.getName())) {
+                                    return request.getSystemProperties().entrySet().stream()
+                                            .collect(Collectors.toMap(
+                                                    e -> e.getKey().toString(),
+                                                    e -> e.getValue().toString()));
+                                } else if ("getUserProperties".equals(method.getName())) {
+                                    return request.getUserProperties().entrySet().stream()
+                                            .collect(Collectors.toMap(
+                                                    e -> e.getKey().toString(),
+                                                    e -> e.getValue().toString()));
+                                } else if ("getService".equals(method.getName())) {
+                                    if (args[0] == SettingsXmlFactory.class) {
+                                        return settingsXmlFactory;
+                                    }
+                                }
+                                return null;
+                            }))
+                    .globalSettingsSource(toSource(request.getGlobalSettingsFile(), request.getGlobalSettingsSource()))
+                    .projectSettingsSource(
+                            toSource(request.getProjectSettingsFile(), request.getProjectSettingsSource()))
+                    .userSettingsSource(toSource(request.getUserSettingsFile(), request.getUserSettingsSource()))
+                    .build());
 
-        Source projectSettingsSource =
-                getSettingsSource(request.getProjectSettingsFile(), request.getProjectSettingsSource());
-        Settings projectSettings = readSettings(projectSettingsSource, true, request, problems);
-
-        Source userSettingsSource = getSettingsSource(request.getUserSettingsFile(), request.getUserSettingsSource());
-        Settings userSettings = readSettings(userSettingsSource, false, request, problems);
-
-        settingsMerger.merge(projectSettings, globalSettings, TrackableBase.GLOBAL_LEVEL);
-        settingsMerger.merge(userSettings, projectSettings, TrackableBase.PROJECT_LEVEL);
-
-        // If no repository is defined in the user/global settings,
-        // it means that we have "old" settings (as those are new in 4.0)
-        // so add central to the computed settings for backward compatibility.
-        if (userSettings.getRepositories().isEmpty()
-                && userSettings.getPluginRepositories().isEmpty()) {
-            Repository central = new Repository();
-            central.setId("central");
-            central.setName("Central Repository");
-            central.setUrl("https://repo.maven.apache.org/maven2");
-            RepositoryPolicy disabledPolicy = new RepositoryPolicy();
-            disabledPolicy.setEnabled(false);
-            central.setSnapshots(disabledPolicy);
-            userSettings.getRepositories().add(central);
-            central = central.clone();
-            RepositoryPolicy updateNeverPolicy = new RepositoryPolicy();
-            disabledPolicy.setUpdatePolicy("never");
-            central.setReleases(updateNeverPolicy);
-            userSettings.getPluginRepositories().add(central);
+            return new DefaultSettingsBuildingResult(
+                    new Settings(result.getEffectiveSettings()), convert(result.getProblems()));
+        } catch (SettingsBuilderException e) {
+            throw new SettingsBuildingException(convert(e.getProblems()));
         }
-
-        problems.setSource("");
-
-        // for the special case of a drive-relative Windows path, make sure it's absolute to save plugins from trouble
-        String localRepository = userSettings.getLocalRepository();
-        if (localRepository != null && !localRepository.isEmpty()) {
-            File file = new File(localRepository);
-            if (!file.isAbsolute() && file.getPath().startsWith(File.separator)) {
-                userSettings.setLocalRepository(file.getAbsolutePath());
-            }
-        }
-
-        if (hasErrors(problems.getProblems())) {
-            throw new SettingsBuildingException(problems.getProblems());
-        }
-
-        return new DefaultSettingsBuildingResult(userSettings, problems.getProblems());
     }
 
-    private boolean hasErrors(List<SettingsProblem> problems) {
-        if (problems != null) {
-            for (SettingsProblem problem : problems) {
-                if (SettingsProblem.Severity.ERROR.compareTo(problem.getSeverity()) >= 0) {
-                    return true;
+    private org.apache.maven.api.services.Source toSource(File file, Source source) {
+        if (file != null && file.exists()) {
+            return org.apache.maven.api.services.Source.fromPath(file.toPath());
+        } else if (source instanceof FileSource fs) {
+            return org.apache.maven.api.services.Source.fromPath(fs.getPath());
+        } else if (source != null) {
+            return new org.apache.maven.api.services.Source() {
+                @Override
+                public Path getPath() {
+                    return null;
                 }
-            }
-        }
 
-        return false;
+                @Override
+                public InputStream openStream() throws IOException {
+                    return source.getInputStream();
+                }
+
+                @Override
+                public String getLocation() {
+                    return source.getLocation();
+                }
+
+                @Override
+                public org.apache.maven.api.services.Source resolve(String relative) {
+                    return null;
+                }
+            };
+        } else {
+            return null;
+        }
     }
 
-    private Source getSettingsSource(File settingsFile, Source settingsSource) {
-        if (settingsSource != null) {
-            return settingsSource;
-        } else if (settingsFile != null && settingsFile.exists()) {
-            return new FileSource(settingsFile);
-        }
-        return null;
+    private List<SettingsProblem> convert(List<BuilderProblem> problems) {
+        return problems.stream().map(this::convert).toList();
     }
 
-    private Settings readSettings(
-            Source settingsSource,
-            boolean isProjectSettings,
-            SettingsBuildingRequest request,
-            DefaultSettingsProblemCollector problems) {
-        if (settingsSource == null) {
-            return new Settings();
-        }
-
-        problems.setSource(settingsSource.getLocation());
-
-        Settings settings;
-
-        try {
-            Map<String, Object> options = new HashMap<>();
-            options.put(SettingsReader.IS_STRICT, Boolean.TRUE);
-            options.put(InputSource.class.getName(), new InputSource(settingsSource.getLocation()));
-            try {
-                settings = settingsReader.read(settingsSource.getInputStream(), options);
-            } catch (SettingsParseException e) {
-                options = Collections.singletonMap(SettingsReader.IS_STRICT, Boolean.FALSE);
-
-                settings = settingsReader.read(settingsSource.getInputStream(), options);
-
-                problems.add(
-                        SettingsProblem.Severity.WARNING, e.getMessage(), e.getLineNumber(), e.getColumnNumber(), e);
-            }
-        } catch (SettingsParseException e) {
-            problems.add(
-                    SettingsProblem.Severity.FATAL,
-                    "Non-parseable settings " + settingsSource.getLocation() + ": " + e.getMessage(),
-                    e.getLineNumber(),
-                    e.getColumnNumber(),
-                    e);
-            return new Settings();
-        } catch (IOException e) {
-            problems.add(
-                    SettingsProblem.Severity.FATAL,
-                    "Non-readable settings " + settingsSource.getLocation() + ": " + e.getMessage(),
-                    -1,
-                    -1,
-                    e);
-            return new Settings();
-        }
-
-        settings = interpolate(settings, request, problems);
-
-        settingsValidator.validate(settings, isProjectSettings, problems);
-
-        if (isProjectSettings) {
-            settings.setLocalRepository(null);
-            settings.setInteractiveMode(true);
-            settings.setOffline(false);
-            settings.setProxies(Collections.emptyList());
-            settings.setUsePluginRegistry(false);
-            for (Server server : settings.getServers()) {
-                server.setUsername(null);
-                server.setPassword(null);
-                server.setPrivateKey(null);
-                server.setPassword(null);
-                server.setFilePermissions(null);
-                server.setDirectoryPermissions(null);
-            }
-        }
-
-        return settings;
-    }
-
-    private Settings interpolate(
-            Settings settings, SettingsBuildingRequest request, SettingsProblemCollector problems) {
-
-        RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
-
-        interpolator.addValueSource(new PropertiesBasedValueSource(request.getUserProperties()));
-
-        interpolator.addValueSource(new PropertiesBasedValueSource(request.getSystemProperties()));
-
-        try {
-            interpolator.addValueSource(new EnvarBasedValueSource());
-        } catch (IOException e) {
-            problems.add(
-                    SettingsProblem.Severity.WARNING,
-                    "Failed to use environment variables for interpolation: " + e.getMessage(),
-                    -1,
-                    -1,
-                    e);
-        }
-
-        return new Settings(new SettingsTransformer(value -> {
-                    try {
-                        return value != null ? interpolator.interpolate(value) : null;
-                    } catch (InterpolationException e) {
-                        problems.add(
-                                SettingsProblem.Severity.WARNING,
-                                "Failed to interpolate settings: " + e.getMessage(),
-                                -1,
-                                -1,
-                                e);
-                        return value;
-                    }
-                })
-                .visit(settings.getDelegate()));
+    private SettingsProblem convert(BuilderProblem problem) {
+        return new DefaultSettingsProblem(
+                problem.getMessage(),
+                SettingsProblem.Severity.valueOf(problem.getSeverity().name()),
+                problem.getSource(),
+                problem.getLineNumber(),
+                problem.getColumnNumber(),
+                problem.getException());
     }
 }

maven-settings-builder/src/main/java/org/apache/maven/settings/building/DefaultSettingsBuilderFactory.java

@@ -43,7 +43,7 @@ public class DefaultSettingsBuilderFactory {
     }
 
     protected SettingsValidator newSettingsValidator() {
-        return new DefaultSettingsValidator();
+        return new DefaultSettingsValidator(new org.apache.maven.internal.impl.DefaultSettingsBuilder());
     }
 
     /**
@@ -52,6 +52,8 @@ public class DefaultSettingsBuilderFactory {
      * @return The new settings builder instance, never {@code null}.
      */
     public DefaultSettingsBuilder newInstance() {
-        return new DefaultSettingsBuilder(newSettingsReader(), newSettingsWriter(), newSettingsValidator());
+        return new DefaultSettingsBuilder(
+                new org.apache.maven.internal.impl.DefaultSettingsBuilder(),
+                new org.apache.maven.internal.impl.DefaultSettingsXmlFactory());
     }
 }

maven-settings-builder/src/main/java/org/apache/maven/settings/validation/DefaultSettingsValidator.java

@@ -18,19 +18,15 @@
  */
 package org.apache.maven.settings.validation;
 
+import javax.inject.Inject;
 import javax.inject.Named;
 import javax.inject.Singleton;
 
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.regex.Pattern;
 
-import org.apache.maven.settings.Mirror;
-import org.apache.maven.settings.Profile;
-import org.apache.maven.settings.Proxy;
-import org.apache.maven.settings.Repository;
-import org.apache.maven.settings.Server;
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.services.SettingsBuilder;
 import org.apache.maven.settings.Settings;
 import org.apache.maven.settings.building.SettingsProblem.Severity;
 import org.apache.maven.settings.building.SettingsProblemCollector;
@@ -44,7 +40,12 @@ public class DefaultSettingsValidator implements SettingsValidator {
     private static final String ID = "[\\w.-]+";
     private static final Pattern ID_REGEX = Pattern.compile(ID);
 
-    private static final String ILLEGAL_REPO_ID_CHARS = "\\/:\"<>|?*"; // ILLEGAL_FS_CHARS
+    private final SettingsBuilder settingsBuilder;
+
+    @Inject
+    public DefaultSettingsValidator(SettingsBuilder settingsBuilder) {
+        this.settingsBuilder = settingsBuilder;
+    }
 
     @Override
     public void validate(Settings settings, SettingsProblemCollector problems) {
@@ -53,201 +54,9 @@ public class DefaultSettingsValidator implements SettingsValidator {
 
     @Override
     public void validate(Settings settings, boolean isProjectSettings, SettingsProblemCollector problems) {
-        if (isProjectSettings) {
-            String msgS = "is not supported on project settings.";
-            String msgP = "are not supported on project settings.";
-            if (settings.getLocalRepository() != null
-                    && !settings.getLocalRepository().isEmpty()) {
-                addViolation(problems, Severity.WARNING, "localRepository", null, msgS);
-            }
-            if (settings.getInteractiveMode() != null && !settings.getInteractiveMode()) {
-                addViolation(problems, Severity.WARNING, "interactiveMode", null, msgS);
-            }
-            if (settings.isOffline()) {
-                addViolation(problems, Severity.WARNING, "offline", null, msgS);
-            }
-            if (!settings.getProxies().isEmpty()) {
-                addViolation(problems, Severity.WARNING, "proxies", null, msgP);
-            }
-            if (settings.isUsePluginRegistry()) {
-                addViolation(problems, Severity.WARNING, "usePluginRegistry", null, msgS);
-            }
-            List<Server> servers = settings.getServers();
-            for (int i = 0; i < servers.size(); i++) {
-                Server server = servers.get(i);
-                String serverField = "servers.server[" + i + "]";
-                validateStringEmpty(problems, serverField + ".username", server.getUsername(), msgS);
-                validateStringEmpty(problems, serverField + ".password", server.getPassword(), msgS);
-                validateStringEmpty(problems, serverField + ".privateKey", server.getPrivateKey(), msgS);
-                validateStringEmpty(problems, serverField + ".passphrase", server.getPassphrase(), msgS);
-                validateStringEmpty(problems, serverField + ".filePermissions", server.getFilePermissions(), msgS);
-                validateStringEmpty(
-                        problems, serverField + ".directoryPermissions", server.getDirectoryPermissions(), msgS);
-            }
-        }
-
-        if (settings.isUsePluginRegistry()) {
-            addViolation(problems, Severity.WARNING, "usePluginRegistry", null, "is deprecated and has no effect.");
-        }
-
-        List<String> pluginGroups = settings.getPluginGroups();
-
-        if (pluginGroups != null) {
-            for (int i = 0; i < pluginGroups.size(); i++) {
-                String pluginGroup = pluginGroups.get(i);
-
-                validateStringNotEmpty(problems, "pluginGroups.pluginGroup[" + i + "]", pluginGroup, null);
-
-                if (!ID_REGEX.matcher(pluginGroup).matches()) {
-                    addViolation(
-                            problems,
-                            Severity.ERROR,
-                            "pluginGroups.pluginGroup[" + i + "]",
-                            null,
-                            "must denote a valid group id and match the pattern " + ID);
-                }
-            }
-        }
-
-        List<Server> servers = settings.getServers();
-
-        if (servers != null) {
-            Set<String> serverIds = new HashSet<>();
-
-            for (int i = 0; i < servers.size(); i++) {
-                Server server = servers.get(i);
-
-                validateStringNotEmpty(problems, "servers.server[" + i + "].id", server.getId(), null);
-
-                if (!serverIds.add(server.getId())) {
-                    addViolation(
-                            problems,
-                            Severity.WARNING,
-                            "servers.server.id",
-                            null,
-                            "must be unique but found duplicate server with id " + server.getId());
-                }
-            }
-        }
-
-        List<Mirror> mirrors = settings.getMirrors();
-
-        if (mirrors != null) {
-            for (Mirror mirror : mirrors) {
-                validateStringNotEmpty(problems, "mirrors.mirror.id", mirror.getId(), mirror.getUrl());
-
-                validateBannedCharacters(
-                        problems, "mirrors.mirror.id", Severity.WARNING, mirror.getId(), null, ILLEGAL_REPO_ID_CHARS);
-
-                if ("local".equals(mirror.getId())) {
-                    addViolation(
-                            problems,
-                            Severity.WARNING,
-                            "mirrors.mirror.id",
-                            null,
-                            "must not be 'local'"
-                                    + ", this identifier is reserved for the local repository"
-                                    + ", using it for other repositories will corrupt your repository metadata.");
-                }
-
-                validateStringNotEmpty(problems, "mirrors.mirror.url", mirror.getUrl(), mirror.getId());
-
-                validateStringNotEmpty(problems, "mirrors.mirror.mirrorOf", mirror.getMirrorOf(), mirror.getId());
-            }
-        }
-
-        List<Profile> profiles = settings.getProfiles();
-
-        if (profiles != null) {
-            Set<String> profileIds = new HashSet<>();
-
-            for (Profile profile : profiles) {
-                if (!profileIds.add(profile.getId())) {
-                    addViolation(
-                            problems,
-                            Severity.WARNING,
-                            "profiles.profile.id",
-                            null,
-                            "must be unique but found duplicate profile with id " + profile.getId());
-                }
-
-                String prefix = "profiles.profile[" + profile.getId() + "].";
-
-                validateRepositories(problems, profile.getRepositories(), prefix + "repositories.repository");
-                validateRepositories(
-                        problems, profile.getPluginRepositories(), prefix + "pluginRepositories.pluginRepository");
-            }
-        }
-
-        List<Proxy> proxies = settings.getProxies();
-
-        if (proxies != null) {
-            Set<String> proxyIds = new HashSet<>();
-
-            for (Proxy proxy : proxies) {
-                if (!proxyIds.add(proxy.getId())) {
-                    addViolation(
-                            problems,
-                            Severity.WARNING,
-                            "proxies.proxy.id",
-                            null,
-                            "must be unique but found duplicate proxy with id " + proxy.getId());
-                }
-                validateStringNotEmpty(problems, "proxies.proxy.host", proxy.getHost(), proxy.getId());
-
-                try {
-                    Integer.parseInt(proxy.getPortString());
-                } catch (NumberFormatException e) {
-                    addViolation(
-                            problems,
-                            Severity.ERROR,
-                            "proxies.proxy[" + proxy.getId() + "].port",
-                            null,
-                            "must be a valid integer but found '" + proxy.getPortString() + "'");
-                }
-            }
-        }
-    }
-
-    private void validateRepositories(SettingsProblemCollector problems, List<Repository> repositories, String prefix) {
-        Set<String> repoIds = new HashSet<>();
-
-        for (Repository repository : repositories) {
-            validateStringNotEmpty(problems, prefix + ".id", repository.getId(), repository.getUrl());
-
-            validateBannedCharacters(
-                    problems, prefix + ".id", Severity.WARNING, repository.getId(), null, ILLEGAL_REPO_ID_CHARS);
-
-            if ("local".equals(repository.getId())) {
-                addViolation(
-                        problems,
-                        Severity.WARNING,
-                        prefix + ".id",
-                        null,
-                        "must not be 'local'"
-                                + ", this identifier is reserved for the local repository"
-                                + ", using it for other repositories will corrupt your repository metadata.");
-            }
-
-            if (!repoIds.add(repository.getId())) {
-                addViolation(
-                        problems,
-                        Severity.WARNING,
-                        prefix + ".id",
-                        null,
-                        "must be unique but found duplicate repository with id " + repository.getId());
-            }
-
-            validateStringNotEmpty(problems, prefix + ".url", repository.getUrl(), repository.getId());
-
-            if ("legacy".equals(repository.getLayout())) {
-                addViolation(
-                        problems,
-                        Severity.WARNING,
-                        prefix + ".layout",
-                        repository.getId(),
-                        "uses the unsupported value 'legacy', artifact resolution might fail.");
-            }
+        List<BuilderProblem> list = settingsBuilder.validate(settings.getDelegate(), isProjectSettings);
+        for (BuilderProblem problem : list) {
+            addViolation(problems, Severity.valueOf(problem.getSeverity().name()), problem.getMessage());
         }
     }
 
@@ -255,101 +64,7 @@ public class DefaultSettingsValidator implements SettingsValidator {
     // Field validation
     // ----------------------------------------------------------------------
 
-    /**
-     * Asserts:
-     * <p/>
-     * <ul>
-     * <li><code>string.length == null</code>
-     * <li><code>string.length == 0</code>
-     * </ul>
-     */
-    private static boolean validateStringEmpty(
-            SettingsProblemCollector problems, String fieldName, String string, String message) {
-        if (string == null || string.length() == 0) {
-            return true;
-        }
-
-        addViolation(problems, Severity.WARNING, fieldName, null, message);
-
-        return false;
-    }
-
-    /**
-     * Asserts:
-     * <p/>
-     * <ul>
-     * <li><code>string.length != null</code>
-     * <li><code>string.length > 0</code>
-     * </ul>
-     */
-    private static boolean validateStringNotEmpty(
-            SettingsProblemCollector problems, String fieldName, String string, String sourceHint) {
-        if (!validateNotNull(problems, fieldName, string, sourceHint)) {
-            return false;
-        }
-
-        if (!string.isEmpty()) {
-            return true;
-        }
-
-        addViolation(problems, Severity.ERROR, fieldName, sourceHint, "is missing");
-
-        return false;
-    }
-
-    /**
-     * Asserts:
-     * <p/>
-     * <ul>
-     * <li><code>string != null</code>
-     * </ul>
-     */
-    private static boolean validateNotNull(
-            SettingsProblemCollector problems, String fieldName, Object object, String sourceHint) {
-        if (object != null) {
-            return true;
-        }
-
-        addViolation(problems, Severity.ERROR, fieldName, sourceHint, "is missing");
-
-        return false;
-    }
-
-    private static boolean validateBannedCharacters(
-            SettingsProblemCollector problems,
-            String fieldName,
-            Severity severity,
-            String string,
-            String sourceHint,
-            String banned) {
-        if (string != null) {
-            for (int i = string.length() - 1; i >= 0; i--) {
-                if (banned.indexOf(string.charAt(i)) >= 0) {
-                    addViolation(
-                            problems,
-                            severity,
-                            fieldName,
-                            sourceHint,
-                            "must not contain any of these characters " + banned + " but found " + string.charAt(i));
-                    return false;
-                }
-            }
-        }
-
-        return true;
-    }
-
-    private static void addViolation(
-            SettingsProblemCollector problems, Severity severity, String fieldName, String sourceHint, String message) {
-        StringBuilder buffer = new StringBuilder(256);
-        buffer.append('\'').append(fieldName).append('\'');
-
-        if (sourceHint != null) {
-            buffer.append(" for ").append(sourceHint);
-        }
-
-        buffer.append(' ').append(message);
-
-        problems.add(severity, buffer.toString(), -1, -1, null);
+    private static void addViolation(SettingsProblemCollector problems, Severity severity, String message) {
+        problems.add(severity, message, -1, -1, null);
     }
 }

maven-settings-builder/src/test/java/org/apache/maven/settings/validation/DefaultSettingsValidatorTest.java

@@ -21,6 +21,7 @@ package org.apache.maven.settings.validation;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.maven.internal.impl.DefaultSettingsBuilder;
 import org.apache.maven.settings.Mirror;
 import org.apache.maven.settings.Profile;
 import org.apache.maven.settings.Proxy;
@@ -44,7 +45,7 @@ class DefaultSettingsValidatorTest {
 
     @BeforeEach
     void setUp() throws Exception {
-        validator = new DefaultSettingsValidator();
+        validator = new DefaultSettingsValidator(new DefaultSettingsBuilder());
     }
 
     @AfterEach

maven-toolchain-builder/pom.xml

@@ -31,6 +31,10 @@ under the License.
   <description>The effective toolchain builder.</description>
 
   <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-impl</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-toolchain-model</artifactId>
@@ -53,6 +57,11 @@ under the License.
       <artifactId>mockito-core</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

maven-toolchain-builder/src/main/java/org/apache/maven/toolchain/building/DefaultToolchainsBuilder.java

@@ -23,25 +23,27 @@ import javax.inject.Named;
 import javax.inject.Singleton;
 
 import java.io.IOException;
-import java.io.StringReader;
-import java.io.StringWriter;
-import java.util.Collections;
+import java.io.InputStream;
+import java.lang.reflect.Method;
+import java.nio.file.Path;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Properties;
 
+import org.apache.maven.api.Session;
+import org.apache.maven.api.services.BuilderProblem;
+import org.apache.maven.api.services.Source;
+import org.apache.maven.api.services.ToolchainsBuilderException;
+import org.apache.maven.api.services.ToolchainsBuilderRequest;
+import org.apache.maven.api.services.ToolchainsBuilderResult;
+import org.apache.maven.api.services.xml.ToolchainsXmlFactory;
+import org.apache.maven.building.FileSource;
 import org.apache.maven.building.Problem;
 import org.apache.maven.building.ProblemCollector;
 import org.apache.maven.building.ProblemCollectorFactory;
-import org.apache.maven.building.Source;
-import org.apache.maven.toolchain.io.ToolchainsParseException;
-import org.apache.maven.toolchain.io.ToolchainsReader;
-import org.apache.maven.toolchain.io.ToolchainsWriter;
-import org.apache.maven.toolchain.merge.MavenToolchainMerger;
 import org.apache.maven.toolchain.model.PersistedToolchains;
-import org.apache.maven.toolchain.model.TrackableBase;
-import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
-import org.codehaus.plexus.interpolation.InterpolationException;
-import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
+import org.codehaus.plexus.interpolation.os.OperatingSystemUtils;
 
 /**
  *
@@ -50,143 +52,88 @@ import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
 @Named
 @Singleton
 public class DefaultToolchainsBuilder implements ToolchainsBuilder {
-    private final MavenToolchainMerger toolchainsMerger = new MavenToolchainMerger();
-    private final ToolchainsWriter toolchainsWriter;
-    private final ToolchainsReader toolchainsReader;
+    private final org.apache.maven.api.services.ToolchainsBuilder builder;
+    private final ToolchainsXmlFactory toolchainsXmlFactory;
 
     @Inject
-    public DefaultToolchainsBuilder(ToolchainsWriter toolchainsWriter, ToolchainsReader toolchainsReader) {
-        this.toolchainsWriter = toolchainsWriter;
-        this.toolchainsReader = toolchainsReader;
+    public DefaultToolchainsBuilder(
+            org.apache.maven.api.services.ToolchainsBuilder builder, ToolchainsXmlFactory toolchainsXmlFactory) {
+        this.builder = builder;
+        this.toolchainsXmlFactory = toolchainsXmlFactory;
     }
 
     @Override
     public ToolchainsBuildingResult build(ToolchainsBuildingRequest request) throws ToolchainsBuildingException {
-        ProblemCollector problems = ProblemCollectorFactory.newInstance(null);
+        try {
+            ToolchainsBuilderResult result = builder.build(ToolchainsBuilderRequest.builder()
+                    .session((Session) java.lang.reflect.Proxy.newProxyInstance(
+                            Session.class.getClassLoader(),
+                            new Class[] {Session.class},
+                            (Object proxy, Method method, Object[] args) -> {
+                                if ("getSystemProperties".equals(method.getName())) {
+                                    Map<String, String> properties = new HashMap<>();
+                                    Properties env = OperatingSystemUtils.getSystemEnvVars();
+                                    env.stringPropertyNames()
+                                            .forEach(k -> properties.put("env." + k, env.getProperty(k)));
+                                    return properties;
+                                } else if ("getUserProperties".equals(method.getName())) {
+                                    return Map.of();
+                                } else if ("getService".equals(method.getName())) {
+                                    if (args[0] == ToolchainsXmlFactory.class) {
+                                        return toolchainsXmlFactory;
+                                    }
+                                }
+                                return null;
+                            }))
+                    .globalToolchainsSource(convert(request.getGlobalToolchainsSource()))
+                    .userToolchainsSource(convert(request.getUserToolchainsSource()))
+                    .build());
 
-        PersistedToolchains globalToolchains = readToolchains(request.getGlobalToolchainsSource(), request, problems);
-
-        PersistedToolchains userToolchains = readToolchains(request.getUserToolchainsSource(), request, problems);
-
-        toolchainsMerger.merge(userToolchains, globalToolchains, TrackableBase.GLOBAL_LEVEL);
-
-        problems.setSource("");
-
-        userToolchains = interpolate(userToolchains, problems);
-
-        if (hasErrors(problems.getProblems())) {
-            throw new ToolchainsBuildingException(problems.getProblems());
+            return new DefaultToolchainsBuildingResult(
+                    new PersistedToolchains(result.getEffectiveToolchains()), convert(result.getProblems()));
+        } catch (ToolchainsBuilderException e) {
+            throw new ToolchainsBuildingException(convert(e.getProblems()));
         }
-
-        return new DefaultToolchainsBuildingResult(userToolchains, problems.getProblems());
     }
 
-    private PersistedToolchains interpolate(PersistedToolchains toolchains, ProblemCollector problems) {
-
-        StringWriter stringWriter = new StringWriter(1024 * 4);
-        try {
-            toolchainsWriter.write(stringWriter, null, toolchains);
-        } catch (IOException e) {
-            throw new IllegalStateException("Failed to serialize toolchains to memory", e);
-        }
-
-        String serializedToolchains = stringWriter.toString();
-
-        RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
-
-        try {
-            interpolator.addValueSource(new EnvarBasedValueSource());
-        } catch (IOException e) {
-            problems.add(
-                    Problem.Severity.WARNING,
-                    "Failed to use environment variables for interpolation: " + e.getMessage(),
-                    -1,
-                    -1,
-                    e);
-        }
-
-        interpolator.addPostProcessor((expression, value) -> {
-            if (value != null) {
-                // we're going to parse this back in as XML so we need to escape XML markup
-                value = value.toString()
-                        .replace("&", "&amp;")
-                        .replace("<", "&lt;")
-                        .replace(">", "&gt;");
-                return value;
-            }
-            return null;
-        });
-
-        try {
-            serializedToolchains = interpolator.interpolate(serializedToolchains);
-        } catch (InterpolationException e) {
-            problems.add(Problem.Severity.ERROR, "Failed to interpolate toolchains: " + e.getMessage(), -1, -1, e);
-            return toolchains;
-        }
-
-        PersistedToolchains result;
-        try {
-            Map<String, ?> options = Collections.singletonMap(ToolchainsReader.IS_STRICT, Boolean.FALSE);
-
-            result = toolchainsReader.read(new StringReader(serializedToolchains), options);
-        } catch (IOException e) {
-            problems.add(Problem.Severity.ERROR, "Failed to interpolate toolchains: " + e.getMessage(), -1, -1, e);
-            return toolchains;
-        }
-
-        return result;
-    }
-
-    private PersistedToolchains readToolchains(
-            Source toolchainsSource, ToolchainsBuildingRequest request, ProblemCollector problems) {
-        if (toolchainsSource == null) {
-            return new PersistedToolchains();
-        }
-
-        PersistedToolchains toolchains;
-
-        try {
-            Map<String, ?> options = Collections.singletonMap(ToolchainsReader.IS_STRICT, Boolean.TRUE);
-
-            try {
-                toolchains = toolchainsReader.read(toolchainsSource.getInputStream(), options);
-            } catch (ToolchainsParseException e) {
-                options = Collections.singletonMap(ToolchainsReader.IS_STRICT, Boolean.FALSE);
-
-                toolchains = toolchainsReader.read(toolchainsSource.getInputStream(), options);
-
-                problems.add(Problem.Severity.WARNING, e.getMessage(), e.getLineNumber(), e.getColumnNumber(), e);
-            }
-        } catch (ToolchainsParseException e) {
-            problems.add(
-                    Problem.Severity.FATAL,
-                    "Non-parseable toolchains " + toolchainsSource.getLocation() + ": " + e.getMessage(),
-                    e.getLineNumber(),
-                    e.getColumnNumber(),
-                    e);
-            return new PersistedToolchains();
-        } catch (IOException e) {
-            problems.add(
-                    Problem.Severity.FATAL,
-                    "Non-readable toolchains " + toolchainsSource.getLocation() + ": " + e.getMessage(),
-                    -1,
-                    -1,
-                    e);
-            return new PersistedToolchains();
-        }
-
-        return toolchains;
-    }
-
-    private boolean hasErrors(List<Problem> problems) {
-        if (problems != null) {
-            for (Problem problem : problems) {
-                if (Problem.Severity.ERROR.compareTo(problem.getSeverity()) >= 0) {
-                    return true;
+    private Source convert(org.apache.maven.building.Source source) {
+        if (source instanceof FileSource fs) {
+            return Source.fromPath(fs.getPath());
+        } else if (source != null) {
+            return new Source() {
+                @Override
+                public Path getPath() {
+                    return null;
                 }
-            }
-        }
 
-        return false;
+                @Override
+                public InputStream openStream() throws IOException {
+                    return source.getInputStream();
+                }
+
+                @Override
+                public String getLocation() {
+                    return source.getLocation();
+                }
+
+                @Override
+                public Source resolve(String relative) {
+                    return null;
+                }
+            };
+        } else {
+            return null;
+        }
+    }
+
+    private List<Problem> convert(List<BuilderProblem> problems) {
+        ProblemCollector collector = ProblemCollectorFactory.newInstance(null);
+        problems.forEach(p -> collector.add(
+                Problem.Severity.valueOf(p.getSeverity().name()),
+                p.getMessage(),
+                p.getLineNumber(),
+                p.getColumnNumber(),
+                p.getException()));
+        return collector.getProblems();
     }
 }

maven-toolchain-builder/src/test/java/org/apache/maven/toolchain/building/DefaultToolchainsBuilderTest.java

@@ -18,54 +18,61 @@
  */
 package org.apache.maven.toolchain.building;
 
+import javax.xml.stream.Location;
+import javax.xml.stream.XMLStreamException;
+
 import java.io.IOException;
-import java.io.InputStream;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
 
+import org.apache.maven.api.services.xml.XmlReaderException;
+import org.apache.maven.api.services.xml.XmlReaderRequest;
+import org.apache.maven.building.Source;
 import org.apache.maven.building.StringSource;
-import org.apache.maven.toolchain.io.DefaultToolchainsReader;
-import org.apache.maven.toolchain.io.DefaultToolchainsWriter;
-import org.apache.maven.toolchain.io.ToolchainsParseException;
+import org.apache.maven.internal.impl.DefaultToolchainsXmlFactory;
 import org.apache.maven.toolchain.model.PersistedToolchains;
 import org.apache.maven.toolchain.model.ToolchainModel;
 import org.codehaus.plexus.interpolation.os.OperatingSystemUtils;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.mockito.ArgumentMatchers;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.InjectMocks;
-import org.mockito.MockitoAnnotations;
 import org.mockito.Spy;
+import org.mockito.junit.jupiter.MockitoExtension;
 
+import static org.apache.maven.internal.impl.StaxLocation.getLocation;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
+@ExtendWith(MockitoExtension.class)
 class DefaultToolchainsBuilderTest {
     private static final String LS = System.lineSeparator();
 
     @Spy
-    private DefaultToolchainsReader toolchainsReader;
-
-    @Spy
-    private DefaultToolchainsWriter toolchainsWriter;
+    private DefaultToolchainsXmlFactory toolchainsXmlFactory;
 
     @InjectMocks
     private DefaultToolchainsBuilder toolchainBuilder;
 
     @BeforeEach
     void onSetup() {
-        MockitoAnnotations.initMocks(this);
+        // MockitoAnnotations.openMocks(this);
 
         Map<String, String> envVarMap = new HashMap<>();
         envVarMap.put("testKey", "testValue");
         envVarMap.put("testSpecialCharactersKey", "<test&Value>");
         OperatingSystemUtils.setEnvVarSource(new TestEnvVarSource(envVarMap));
+
+        toolchainBuilder = new DefaultToolchainsBuilder(
+                new org.apache.maven.internal.impl.DefaultToolchainsBuilder(), toolchainsXmlFactory);
     }
 
     @Test
@@ -79,19 +86,17 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testBuildRequestWithUserToolchains() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setUserToolchainsSource(new StringSource(""));
-
         Properties props = new Properties();
         props.put("key", "user_value");
         ToolchainModel toolchain = new ToolchainModel();
         toolchain.setType("TYPE");
         toolchain.setProvides(props);
-        PersistedToolchains userResult = new PersistedToolchains();
-        userResult.setToolchains(Collections.singletonList(toolchain));
-        doReturn(userResult)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        PersistedToolchains persistedToolchains = new PersistedToolchains();
+        persistedToolchains.setToolchains(Collections.singletonList(toolchain));
+
+        String xml = new DefaultToolchainsXmlFactory().toXmlString(persistedToolchains.getDelegate());
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setUserToolchainsSource(new StringSource(xml));
 
         ToolchainsBuildingResult result = toolchainBuilder.build(request);
         assertNotNull(result.getEffectiveToolchains());
@@ -111,19 +116,17 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testBuildRequestWithGlobalToolchains() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setGlobalToolchainsSource(new StringSource(""));
-
         Properties props = new Properties();
         props.put("key", "global_value");
         ToolchainModel toolchain = new ToolchainModel();
         toolchain.setType("TYPE");
         toolchain.setProvides(props);
-        PersistedToolchains globalResult = new PersistedToolchains();
-        globalResult.setToolchains(Collections.singletonList(toolchain));
-        doReturn(globalResult)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        PersistedToolchains persistedToolchains = new PersistedToolchains();
+        persistedToolchains.setToolchains(Collections.singletonList(toolchain));
+
+        String xml = new DefaultToolchainsXmlFactory().toXmlString(persistedToolchains.getDelegate());
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setGlobalToolchainsSource(new StringSource(xml));
 
         ToolchainsBuildingResult result = toolchainBuilder.build(request);
         assertNotNull(result.getEffectiveToolchains());
@@ -143,10 +146,6 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testBuildRequestWithBothToolchains() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setGlobalToolchainsSource(new StringSource(""));
-        request.setUserToolchainsSource(new StringSource(""));
-
         Properties props = new Properties();
         props.put("key", "user_value");
         ToolchainModel toolchain = new ToolchainModel();
@@ -163,10 +162,11 @@ class DefaultToolchainsBuilderTest {
         PersistedToolchains globalResult = new PersistedToolchains();
         globalResult.setToolchains(Collections.singletonList(toolchain));
 
-        doReturn(globalResult)
-                .doReturn(userResult)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setUserToolchainsSource(
+                new StringSource(new DefaultToolchainsXmlFactory().toXmlString(userResult.getDelegate())));
+        request.setGlobalToolchainsSource(
+                new StringSource(new DefaultToolchainsXmlFactory().toXmlString(globalResult.getDelegate())));
 
         ToolchainsBuildingResult result = toolchainBuilder.build(request);
         assertNotNull(result.getEffectiveToolchains());
@@ -195,12 +195,15 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testStrictToolchainsParseException() throws Exception {
+        Location loc = mock(Location.class);
+        when(loc.getLineNumber()).thenReturn(4);
+        when(loc.getColumnNumber()).thenReturn(2);
+        XMLStreamException parseException = new XMLStreamException("MESSAGE", loc);
+        doThrow(new XmlReaderException("MESSAGE", getLocation(parseException), parseException))
+                .when(toolchainsXmlFactory)
+                .read(any(XmlReaderRequest.class));
         ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
         request.setGlobalToolchainsSource(new StringSource(""));
-        ToolchainsParseException parseException = new ToolchainsParseException("MESSAGE", 4, 2);
-        doThrow(parseException)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
 
         try {
             toolchainBuilder.build(request);
@@ -214,12 +217,13 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testIOException() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setGlobalToolchainsSource(new StringSource("", "LOCATION"));
+        Source src = mock(Source.class);
         IOException ioException = new IOException("MESSAGE");
-        doThrow(ioException)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        doThrow(ioException).when(src).getInputStream();
+        doReturn("LOCATION").when(src).getLocation();
+
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setGlobalToolchainsSource(src);
 
         try {
             toolchainBuilder.build(request);
@@ -233,9 +237,6 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testEnvironmentVariablesAreInterpolated() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setUserToolchainsSource(new StringSource(""));
-
         Properties props = new Properties();
         props.put("key", "${env.testKey}");
         Xpp3Dom configurationChild = new Xpp3Dom("jdkHome");
@@ -249,9 +250,9 @@ class DefaultToolchainsBuilderTest {
         PersistedToolchains persistedToolchains = new PersistedToolchains();
         persistedToolchains.setToolchains(Collections.singletonList(toolchain));
 
-        doReturn(persistedToolchains)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        String xml = new DefaultToolchainsXmlFactory().toXmlString(persistedToolchains.getDelegate());
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setUserToolchainsSource(new StringSource(xml));
 
         ToolchainsBuildingResult result = toolchainBuilder.build(request);
         String interpolatedValue = "testValue";
@@ -272,9 +273,6 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testNonExistingEnvironmentVariablesAreNotInterpolated() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setUserToolchainsSource(new StringSource(""));
-
         Properties props = new Properties();
         props.put("key", "${env.testNonExistingKey}");
         ToolchainModel toolchain = new ToolchainModel();
@@ -283,9 +281,9 @@ class DefaultToolchainsBuilderTest {
         PersistedToolchains persistedToolchains = new PersistedToolchains();
         persistedToolchains.setToolchains(Collections.singletonList(toolchain));
 
-        doReturn(persistedToolchains)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        String xml = new DefaultToolchainsXmlFactory().toXmlString(persistedToolchains.getDelegate());
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setUserToolchainsSource(new StringSource(xml));
 
         ToolchainsBuildingResult result = toolchainBuilder.build(request);
         assertEquals(
@@ -301,9 +299,6 @@ class DefaultToolchainsBuilderTest {
 
     @Test
     void testEnvironmentVariablesWithSpecialCharactersAreInterpolated() throws Exception {
-        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
-        request.setUserToolchainsSource(new StringSource(""));
-
         Properties props = new Properties();
         props.put("key", "${env.testSpecialCharactersKey}");
         ToolchainModel toolchain = new ToolchainModel();
@@ -312,9 +307,9 @@ class DefaultToolchainsBuilderTest {
         PersistedToolchains persistedToolchains = new PersistedToolchains();
         persistedToolchains.setToolchains(Collections.singletonList(toolchain));
 
-        doReturn(persistedToolchains)
-                .when(toolchainsReader)
-                .read(any(InputStream.class), ArgumentMatchers.<String, Object>anyMap());
+        String xml = new DefaultToolchainsXmlFactory().toXmlString(persistedToolchains.getDelegate());
+        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
+        request.setUserToolchainsSource(new StringSource(xml));
 
         ToolchainsBuildingResult result = toolchainBuilder.build(request);
         String interpolatedValue = "<test&Value>";