[MNG-7947] Plugin API (#1309)

* Add an InternalSession interface to avoid casting to the implementation in various places
* Upgrade to Guice 6.0.0 and add support for jakarta.inject annotations
* Maven 4 Plugin API

api/maven-api-core/pom.xml

@@ -51,6 +51,15 @@
       <artifactId>maven-api-toolchain</artifactId>
       <version>4.0.0-alpha-9-SNAPSHOT</version>
     </dependency>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-plugin</artifactId>
+      <version>4.0.0-alpha-9-SNAPSHOT</version>
+    </dependency>
+    <dependency>
+      <groupId>jakarta.inject</groupId>
+      <artifactId>jakarta.inject-api</artifactId>
+    </dependency>
   </dependencies>
 
 </project>

api/maven-api-core/src/main/java/org/apache/maven/api/MojoExecution.java

@@ -22,23 +22,37 @@ import java.util.Optional;
 
 import org.apache.maven.api.annotations.Experimental;
 import org.apache.maven.api.annotations.Nonnull;
-import org.apache.maven.api.model.Plugin;
+import org.apache.maven.api.model.PluginExecution;
+import org.apache.maven.api.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.api.xml.XmlNode;
 
 /**
- * A {@code MojoExecution}
+ * A {@code MojoExecution} represents a single execution of a Maven Plugin during a given build.
+ * An instance of this object is bound to the {@link org.apache.maven.api.di.MojoExecutionScoped}
+ * and available as {@code mojoExecution} within {@link org.apache.maven.api.plugin.annotations.Parameter}
+ * expressions.
  */
 @Experimental
 public interface MojoExecution {
+
     @Nonnull
     Plugin getPlugin();
 
+    @Nonnull
+    PluginExecution getModel();
+
+    @Nonnull
+    MojoDescriptor getDescriptor();
+
     @Nonnull
     String getExecutionId();
 
     @Nonnull
     String getGoal();
 
+    @Nonnull
+    String getLifecyclePhase();
+
     @Nonnull
     Optional<XmlNode> getConfiguration();
 }

api/maven-api-core/src/main/java/org/apache/maven/api/Plugin.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;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.maven.api.annotations.Experimental;
+import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.plugin.descriptor.PluginDescriptor;
+import org.apache.maven.api.plugin.descriptor.lifecycle.Lifecycle;
+
+/**
+ * Represents a maven plugin runtime
+ */
+@Experimental
+public interface Plugin {
+
+    @Nonnull
+    org.apache.maven.api.model.Plugin getModel();
+
+    @Nonnull
+    PluginDescriptor getDescriptor();
+
+    @Nonnull
+    List<Lifecycle> getLifecycles();
+
+    @Nonnull
+    ClassLoader getClassLoader();
+
+    @Nonnull
+    Artifact getArtifact();
+
+    @Nonnull
+    default Collection<Dependency> getDependencies() {
+        return getDependenciesMap().values();
+    }
+
+    @Nonnull
+    Map<String, Dependency> getDependenciesMap();
+}

api/maven-api-core/src/main/java/org/apache/maven/api/Session.java

@@ -214,6 +214,13 @@ public interface Session {
     @Nonnull
     DependencyCoordinate createDependencyCoordinate(@Nonnull ArtifactCoordinate coordinate);
 
+    /**
+     * Shortcut for <code>getService(DependencyFactory.class).create(...)</code>
+     * @see DependencyCoordinateFactory#create(Session, Dependency)
+     */
+    @Nonnull
+    DependencyCoordinate createDependencyCoordinate(@Nonnull Dependency dependency);
+
     /**
      * Shortcut for <code>getService(ArtifactFactory.class).create(...)</code>
      * @see org.apache.maven.api.services.ArtifactFactory#create(Session, String, String, String, String)

api/maven-api-core/src/main/java/org/apache/maven/api/VersionRange.java

@@ -29,7 +29,7 @@ import org.apache.maven.api.annotations.Nonnull;
 @Experimental
 public interface VersionRange {
 
-    // TODO: add access to the version information
+    // TODO: v4: add access to the version information
 
     /**
      * Determines whether the specified version is contained within this range.

api/maven-api-core/src/main/java/org/apache/maven/api/di/MojoExecutionScoped.java

@@ -16,42 +16,26 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-package org.apache.maven.api.plugin.annotations;
+package org.apache.maven.api.di;
 
 import java.lang.annotation.Documented;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Inherited;
 import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
-import org.apache.maven.api.annotations.Experimental;
+import jakarta.inject.Scope;
-import org.apache.maven.api.annotations.Nonnull;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
 
 /**
- * Used to configure injection of Plexus components by
+ * Indicates that the annotated bean has a lifespan limited to a given mojo execution,
- * <a href="/ref/current/maven-core/apidocs/org/apache/maven/plugin/MavenPluginManager.html">
+ * which means each mojo execution will result in a different instance being injected.
- * <code>MavenPluginManager.getConfiguredMojo(...)</code></a>.
  *
  * @since 4.0.0
  */
-@Experimental
+@Scope
 @Documented
-@Retention(RetentionPolicy.CLASS)
+@Retention(RUNTIME)
-@Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
+@Target({TYPE, METHOD})
-@Inherited
+public @interface MojoExecutionScoped {}
-public @interface Component {
-    /**
-     * role of the component to inject.
-     * @return the role
-     */
-    @Nonnull
-    Class<?> role() default Object.class;
-
-    /**
-     * hint of the component to inject.
-     * @return the hint
-     */
-    @Nonnull
-    String hint() default "";
-}

api/maven-api-core/src/main/java/org/apache/maven/api/di/SessionScoped.java

@@ -16,29 +16,26 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-package org.apache.maven.api.plugin.annotations;
+package org.apache.maven.api.di;
 
-import org.apache.maven.api.annotations.Experimental;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import jakarta.inject.Scope;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
 
 /**
- * Component instantiation strategy.
+ * Indicates that annotated component should be instantiated before session execution starts
+ * and discarded after session execution completes.
  *
  * @since 4.0.0
  */
-@Experimental
+@Scope
-public enum InstantiationStrategy {
+@Documented
-    PER_LOOKUP("per-lookup"),
+@Retention(RUNTIME)
-    SINGLETON("singleton"),
+@Target({TYPE, METHOD})
-    KEEP_ALIVE("keep-alive"),
+public @interface SessionScoped {}
-    POOLABLE("poolable");
-
-    private final String id;
-
-    InstantiationStrategy(String id) {
-        this.id = id;
-    }
-
-    public String id() {
-        return this.id;
-    }
-}

api/maven-api-core/src/main/java/org/apache/maven/api/feature/Features.java

@@ -34,6 +34,8 @@ public final class Features {
 
     /**
      * Name of the Maven user property to enable or disable the build/consumer POM feature.
+     *
+     * TODO: v4: remove experimental bit
      */
     public static final String BUILDCONSUMER = "maven.experimental.buildconsumer";
 

api/maven-api-core/src/main/java/org/apache/maven/api/plugin/LifecycleProvider.java

@@ -0,0 +1,39 @@
+/*
+ * 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.plugin;
+
+import java.util.List;
+
+import org.apache.maven.api.annotations.Consumer;
+import org.apache.maven.api.annotations.Experimental;
+import org.apache.maven.api.plugin.descriptor.lifecycle.Lifecycle;
+
+/**
+ * Interface that can be provided by the plugin to wire in custom lifecycles
+ * leveraged using the {@link org.apache.maven.api.plugin.annotations.Execute}
+ * annotation.  If a {@code META-INF/maven/lifecycle.xml} file is packaged
+ * in the plugin, Maven will provide a default implementation that will parse
+ * the file and return the contained lifecycle definitions.
+ */
+@Experimental
+@Consumer
+public interface LifecycleProvider {
+
+    List<Lifecycle> getLifecycles();
+}

api/maven-api-core/src/main/java/org/apache/maven/api/plugin/annotations/Mojo.java

@@ -31,6 +31,9 @@ import org.apache.maven.api.annotations.Nonnull;
 
 /**
  * This annotation will mark your class as a Mojo (ie. goal in a Maven plugin).
+ * The mojo can be annotated with {@code jakarta.inject.*} annotations.
+ * The {@link Parameter} annotation can be added on fields to inject data
+ * from the plugin configuration or from other components.
  *
  * @since 4.0.0
  */
@@ -59,27 +62,20 @@ public @interface Mojo {
      * @return the required dependency resolution scope
      */
     @Nonnull
-    ResolutionScope requiresDependencyResolution() default ResolutionScope.NONE;
+    ResolutionScope dependencyResolutionRequired() default ResolutionScope.NONE;
 
     /**
      * the required dependency collection scope.
      * @return the required dependency collection scope
      */
     @Nonnull
-    ResolutionScope requiresDependencyCollection() default ResolutionScope.NONE;
+    ResolutionScope dependencyCollectionRequired() default ResolutionScope.NONE;
-
-    /**
-     * your Mojo instantiation strategy. (Only <code>per-lookup</code> and <code>singleton</code> are supported)
-     * @return the instantiation strategy
-     */
-    @Nonnull
-    InstantiationStrategy instantiationStrategy() default InstantiationStrategy.PER_LOOKUP;
 
     /**
      * does your mojo requires a project to be executed?
      * @return requires a project
      */
-    boolean requiresProject() default true;
+    boolean projectRequired() default true;
 
     /**
      * if the Mojo uses the Maven project and its child modules.
@@ -91,9 +87,10 @@ public @interface Mojo {
      * does this Mojo need to be online to be executed?
      * @return need to be online
      */
-    boolean requiresOnline() default false;
+    boolean onlineRequired() default false;
 
     /**
+     * TODO: v4: add a SPI for the configurator
      * configurator bean name.
      * @return the configurator bean name
      */

api/maven-api-plugin/pom.xml

@@ -0,0 +1,105 @@
+<?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-api</artifactId>
+    <version>4.0.0-alpha-9-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>maven-api-plugin</artifactId>
+
+  <name>Maven 4 API :: Plugin</name>
+  <description>Maven 4 API - Immutable Plugin model.</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-xml</artifactId>
+      <version>4.0.0-alpha-9-SNAPSHOT</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.modello</groupId>
+        <artifactId>modello-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>plugin</id>
+            <goals>
+              <goal>velocity</goal>
+              <goal>xdoc</goal>
+              <goal>xsd</goal>
+            </goals>
+            <phase>generate-resources</phase>
+            <configuration>
+              <velocityBasedir>${project.basedir}/../../src/mdo</velocityBasedir>
+              <version>2.0.0</version>
+              <models>
+                <model>src/main/mdo/plugin.mdo</model>
+              </models>
+              <templates>
+                <template>model.vm</template>
+              </templates>
+              <params>
+                <param>packageModelV4=org.apache.maven.api.plugin.descriptor</param>
+              </params>
+            </configuration>
+          </execution>
+          <execution>
+            <id>lifecycle</id>
+            <goals>
+              <goal>velocity</goal>
+              <goal>xdoc</goal>
+              <goal>xsd</goal>
+            </goals>
+            <phase>generate-resources</phase>
+            <configuration>
+              <velocityBasedir>${project.basedir}/../../src/mdo</velocityBasedir>
+              <version>1.0.0</version>
+              <models>
+                <model>src/main/mdo/lifecycle.mdo</model>
+              </models>
+              <templates>
+                <template>model.vm</template>
+              </templates>
+              <params>
+                <param>packageModelV4=org.apache.maven.api.plugin.descriptor.lifecycle</param>
+              </params>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <excludes>
+            <exclude>**/package-info.java</exclude>
+          </excludes>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>

api/maven-api-plugin/src/main/java/org/apache/maven/api/plugin/descriptor/lifecycle/package-info.java

@@ -0,0 +1,5 @@
+// CHECKSTYLE_OFF: RegexpHeader
+/**
+ * Maven Plugin forked lifecycle model.
+ */
+package org.apache.maven.api.plugin.descriptor.lifecycle;

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

@@ -0,0 +1,5 @@
+// CHECKSTYLE_OFF: RegexpHeader
+/**
+ * Maven Plugin descriptor model.
+ */
+package org.apache.maven.api.plugin.descriptor;

api/maven-api-plugin/src/main/mdo/lifecycle.mdo

@@ -17,22 +17,16 @@ specific language governing permissions and limitations
 under the License.
 -->
 
-<model xmlns="http://codehaus-plexus.github.io/MODELLO/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<model xmlns="http://codehaus-plexus.github.io/MODELLO/2.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xsi:schemaLocation="http://codehaus-plexus.github.io/MODELLO/1.0.0 http://codehaus-plexus.github.io/modello/xsd/modello-1.0.0.xsd"
+  xsi:schemaLocation="http://codehaus-plexus.github.io/MODELLO/2.0.0 http://codehaus-plexus.github.io/modello/xsd/modello-2.0.0.xsd"
   xml.namespace="http://maven.apache.org/LIFECYCLE/${version}"
   xml.schemaLocation="http://maven.apache.org/xsd/lifecycle-${version}.xsd">
-  <id>lifecycle-mappings</id>
+  <id>lifecycle</id>
-  <name>LifecycleMappings</name>
+  <name>Lifecycle</name>
   <description><![CDATA[
     Configuration of custom lifecycle mappings for the plugin, as generally stored in
     <code>META-INF/maven/lifecycle.xml</code> in a plugin's jar artifact.
   ]]></description>
-  <defaults>
-    <default>
-      <key>package</key>
-      <value>org.apache.maven.plugin.lifecycle</value>
-    </default>
-  </defaults>
   <classes>
     <class rootElement="true" xml.tagName="lifecycles" xsd.compositor="sequence">
       <name>LifecycleConfiguration</name>

api/maven-api-plugin/src/main/mdo/plugin.mdo

@@ -24,26 +24,15 @@ under the License.
   <id>plugin</id>
   <name>PluginDescriptor</name>
   <description><![CDATA[
-    Plugin descriptor, stored in <code>META-INF/maven/plugin.xml</code> in a plugin's jar artifact.
+    Maven 4 Plugin descriptor, stored in <code>META-INF/maven/plugin.xml</code> in a plugin's jar artifact.
-    This descriptor is generally generated from plugin sources, using
+    This descriptor is generally using the information contained in the annotations of the plugin api.
-    <a href="/plugins/maven-plugin-plugin/">maven-plugin-plugin</a>.
+    <p>An XSD is available at <a href="https://maven.apache.org/xsd/plugin-2.0.0.xsd">https://maven.apache.org/xsd/plugin-2.0.0.xsd</a></p>
-    <p><i>Notice:</i> this documentation is generated from a Modello model but the
-    <a href="apidocs/org/apache/maven/plugin/descriptor/PluginDescriptor.html"><code>PluginDescriptor</code></a>/<a href="apidocs/org/apache/maven/plugin/descriptor/MojoDescriptor.html"><code>MojoDescriptor</code></a>
-    code executed is not generated from this model. Please report if you find anything wrong this documentation.</p>
-    <p>An XSD is available at <a href="https://maven.apache.org/xsd/plugin-1.1.0.xsd">https://maven.apache.org/xsd/plugin-1.1.0.xsd</a></p>
   ]]></description>
-  <defaults>
-    <default>
-      <key>package</key>
-      <value>plugin descriptor XML documentation (no java generation)</value><!-- intentionally non-buildable value -->
-    </default>
-  </defaults>
   <classes>
     <class rootElement="true" xml.tagName="plugin" xdoc.anchorName="plugin">
       <name>PluginDescriptor</name>
       <version>1.0.0+</version>
       <description><![CDATA[Root element of the <code>plugin.xml</code> file.]]></description>
-      <!-- see o.a.m.plugin.descriptor.PluginDescriptor -->
       <fields>
         <field>
           <name>name</name>
@@ -120,7 +109,7 @@ under the License.
         </field>
         <field xdoc.separator="blank">
           <name>dependencies</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
           <association>
             <type>Dependency</type>
             <multiplicity>*</multiplicity>
@@ -131,6 +120,21 @@ under the License.
           </description>
         </field>
       </fields>
+      <codeSegments>
+        <codeSegment>
+          <version>2.0.0+</version>
+          <code><![CDATA[
+    public String getPluginLookupKey() {
+        return groupId + ":" + artifactId;
+    }
+
+    public String getId() {
+        return groupId + ":" + artifactId + ":" + version;
+    }
+
+          ]]></code>
+        </codeSegment>
+      </codeSegments>
     </class>
 
     <class xdoc.anchorName="mojo">
@@ -139,7 +143,6 @@ under the License.
       <description><![CDATA[
         A Mojo description.
       ]]></description>
-      <!-- see o.a.m.plugin.descriptor.MojoDescriptor -->
       <fields>
         <field>
           <name>goal</name>
@@ -203,7 +206,18 @@ under the License.
         </field>
         <field>
           <name>requiresDependencyResolution</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
+          <type>String</type>
+          <defaultValue>runtime</defaultValue>
+          <description><![CDATA[
+            Flags this Mojo as requiring the dependencies in the specified class path to be resolved before it can
+            execute: <code>compile</code>, <code>runtime</code>, <code>test</code>,
+            <code>compile+runtime</code> (since Maven 3.0) or <code>runtime+system</code> (since Maven 3.0)
+          ]]></description>
+        </field>
+        <field>
+          <name>dependencyResolution</name>
+          <version>2.0.0+</version>
           <type>String</type>
           <defaultValue>runtime</defaultValue>
           <description><![CDATA[
@@ -214,7 +228,20 @@ under the License.
         </field>
         <field>
           <name>requiresDependencyCollection</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
+          <type>String</type>
+          <description><![CDATA[
+            Flags this Mojo as requiring information about the dependencies that would make up the specified class
+            path. As the name suggests, this is similar to requiresDependencyResolution and supports the same values.
+            The important difference is this will not resolve the files for the dependencies, i.e. the artifacts
+            associated with a Maven project can lack a file. As such, this annotation is meant for Mojos that only
+            want to analyze the set of transitive dependencies, in particular during early lifecycle phases where
+            full dependency resolution might fail due to projects which haven't been built yet.
+          ]]></description>
+        </field>
+        <field>
+          <name>dependencyCollection</name>
+          <version>2.0.0+</version>
           <type>String</type>
           <description><![CDATA[
             Flags this Mojo as requiring information about the dependencies that would make up the specified class
@@ -227,14 +254,28 @@ under the License.
         </field>
         <field>
           <name>requiresDirectInvocation</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
+          <type>boolean</type>
+          <description>Flags this Mojo to be invoked directly only.</description>
+          <defaultValue>false</defaultValue>
+        </field>
+        <field>
+          <name>directInvocationOnly</name>
+          <version>2.0.0+</version>
           <type>boolean</type>
           <description>Flags this Mojo to be invoked directly only.</description>
           <defaultValue>false</defaultValue>
         </field>
         <field>
           <name>requiresProject</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
+          <type>boolean</type>
+          <description>Flags this Mojo to require running inside of a project.</description>
+          <defaultValue>true</defaultValue>
+        </field>
+        <field>
+          <name>projectRequired</name>
+          <version>2.0.0+</version>
           <type>boolean</type>
           <description>Flags this Mojo to require running inside of a project.</description>
           <defaultValue>true</defaultValue>
@@ -248,7 +289,14 @@ under the License.
         </field>
         <field>
           <name>requiresOnline</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
+          <type>boolean</type>
+          <description>Flags this Mojo to require online mode for its operation.</description>
+          <defaultValue>false</defaultValue>
+        </field>
+        <field>
+          <name>onlineRequired</name>
+          <version>2.0.0+</version>
           <type>boolean</type>
           <description>Flags this Mojo to require online mode for its operation.</description>
           <defaultValue>false</defaultValue>
@@ -272,7 +320,7 @@ under the License.
         </field>
         <field>
           <name>threadSafe</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
           <type>boolean</type>
           <description>
             Marks this Mojo as being thread-safe, i.e. the Mojo safely supports concurrent execution during parallel
@@ -283,21 +331,21 @@ under the License.
         </field>
         <field>
           <name>v4Api</name>
-          <version>1.1.0+</version>
+          <version>1.1.0</version>
           <type>boolean</type>
           <description>Marks this Mojo as using Maven 4 API. This makes the plugin implicitly incompatible with earlier Maven versions. Only evaluated since Maven 4.</description>
           <defaultValue>false</defaultValue>
         </field>
         <field>
           <name>instantiationStrategy</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
           <type>String</type>
           <defaultValue>per-lookup</defaultValue>
           <description>Specify the instantiation strategy.</description>
         </field>
         <field>
           <name>executionStrategy</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
           <type>String</type>
           <description><![CDATA[
             Specify the execution strategy: <code>once-per-session</code>, <code>always</code>.
@@ -331,7 +379,7 @@ under the License.
         </field>
         <field>
           <name>composer</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
           <type>String</type>
           <description></description>
         </field>
@@ -344,27 +392,27 @@ under the License.
             <multiplicity>*</multiplicity>
           </association>
         </field>
-        <field>
-          <name>configuration</name>
-          <version>1.0.0+</version>
-          <description>Specifies default values of parameters (with attribute "default-value") as well as how they can be overwritten by Maven properties (in the element content).</description>
-          <!-- https://github.com/codehaus-plexus/modello/issues/264 -->
-          <type>DOM</type>
-          <!--
-          <association xml.tagName="paramName">
-            <type>Configuration</type>
-            <multiplicity>*</multiplicity>
-          </association> -->
-        </field>
         <field xdoc.separator="blank">
           <name>requirements</name>
-          <version>1.0.0+</version>
+          <version>1.0.0/1.1.0</version>
           <description></description>
           <association>
             <type>Requirement</type>
             <multiplicity>*</multiplicity>
           </association>
         </field>
+        <field xml.format="((PluginDescriptor.Builder) context.peekLast()).build().getId() + &quot;:&quot; + mojoDescriptor.build().getGoal()">
+          <name>id</name>
+          <version>2.0.0+</version>
+          <type>String</type>
+          <description>the id of the mojo, based on the goal name</description>
+        </field>
+        <field xml.format="((PluginDescriptor.Builder) context.peekLast()).build().getGoalPrefix() + &quot;:&quot; + mojoDescriptor.build().getGoal()">
+          <name>fullGoalName</name>
+          <version>2.0.0+</version>
+          <type>String</type>
+          <description>the full goal name</description>
+        </field>
       </fields>
     </class>
 
@@ -428,12 +476,6 @@ under the License.
             full of Strings.
           ]]></description>
         </field>
-        <field>
-          <name>implementation</name>
-          <version>1.0.0+</version>
-          <type>String</type>
-          <description></description>
-        </field>
         <field>
           <name>description</name>
           <version>1.0.0+</version>
@@ -455,31 +497,15 @@ under the License.
             This will trigger a warning when a user tries to configure a parameter marked as deprecated.
           ]]></description>
         </field>
-      </fields>
+        <field>
-    </class>
-
-    <class>
-      <name>Configuration</name>
-      <version>1.0.0+</version>
-      <description>A parameter configuration.</description>
-      <!-- see o.a.m.plugin.descriptor.Parameter -->
-      <fields>
-        <field xml.content="true">
           <name>expression</name>
-          <required>true</required>
+          <version>2.0.0+</version>
-          <version>1.0.0+</version>
           <type>String</type>
           <description>Parameter expression, to let user override default value with a user property, system property or project property.</description>
         </field>
-        <field xml.attribute="true" xml.tagName="implementation">
+        <field>
-          <name>implementation</name>
-          <version>1.0.0+</version>
-          <type>String</type>
-          <description></description>
-        </field>
-        <field xml.attribute="true" xml.tagName="default-value">
           <name>defaultValue</name>
-          <version>1.0.0+</version>
+          <version>2.0.0+</version>
           <type>String</type>
           <description>The default value, as an expression that will be evaluated at injection or run-time.</description>
         </field>
@@ -488,7 +514,7 @@ under the License.
 
     <class xdoc.anchorName="requirement">
       <name>Requirement</name>
-      <version>1.0.0+</version>
+      <version>1.0.0/1.1.0</version>
       <description>Describes a component requirement.</description>
       <!-- see o.a.m.plugin.descriptor.Requirement -->
       <fields>
@@ -517,7 +543,7 @@ under the License.
 
     <class xdoc.anchorName="dependency">
       <name>Dependency</name>
-      <version>1.0.0+</version>
+      <version>1.0.0/1.1.0</version>
       <description>Definition of a dependency, needed by the plugin at runtime.</description>
       <fields>
         <field>

api/maven-api-plugin/src/site/apt/index.apt

@@ -0,0 +1,33 @@
+~~ 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.
+
+ -----
+ Introduction
+ -----
+ Guillaume Nodet
+ -----
+ 2023-11-15
+ -----
+
+Maven 4 API - Plugin Descriptor Model
+
+ This is the immutable model for Maven Plugin Descriptor in <<<org.apache.maven.api.plugin.descriptor>>> package.
+
+ The following are generated from this model:
+
+   * {{{./apidocs/index.html}Java sources}} with <<<Builder>>> inner classes for immutable instances creation.
+

api/maven-api-plugin/src/site/site.xml

@@ -0,0 +1,38 @@
+<?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/DECORATION/1.8.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/DECORATION/1.8.0 http://maven.apache.org/xsd/decoration-1.8.0.xsd">
+
+  <edit>${project.scm.url}</edit>
+
+  <body>
+    <menu name="Overview">
+      <item name="Introduction" href="index.html"/>
+      <item name="Javadocs" href="apidocs/index.html"/>
+      <item name="Source Xref" href="xref/index.html"/>
+      <!--item name="FAQ" href="faq.html"/-->
+    </menu>
+
+    <menu ref="parent"/>
+    <menu ref="reports"/>
+  </body>
+</project>

api/pom.xml

@@ -35,6 +35,7 @@
     <module>maven-api-meta</module>
     <module>maven-api-xml</module>
     <module>maven-api-model</module>
+    <module>maven-api-plugin</module>
     <module>maven-api-settings</module>
     <module>maven-api-toolchain</module>
     <module>maven-api-core</module>

maven-bom/pom.xml

@@ -122,6 +122,11 @@ under the License.
         <artifactId>maven-api-toolchain</artifactId>
         <version>${project.version}</version>
       </dependency>
+      <dependency>
+        <groupId>org.apache.maven</groupId>
+        <artifactId>maven-api-plugin</artifactId>
+        <version>${project.version}</version>
+      </dependency>
       <dependency>
         <groupId>org.apache.maven</groupId>
         <artifactId>maven-api-xml</artifactId>

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

@@ -36,7 +36,6 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 import java.util.stream.Stream;
 
@@ -60,8 +59,8 @@ import org.apache.maven.graph.GraphBuilder;
 import org.apache.maven.graph.ProjectSelector;
 import org.apache.maven.internal.aether.DefaultRepositorySystemSessionFactory;
 import org.apache.maven.internal.aether.MavenChainedWorkspaceReader;
-import org.apache.maven.internal.impl.DefaultSession;
 import org.apache.maven.internal.impl.DefaultSessionFactory;
+import org.apache.maven.internal.impl.InternalSession;
 import org.apache.maven.lifecycle.LifecycleExecutionException;
 import org.apache.maven.lifecycle.internal.ExecutionEventCatapult;
 import org.apache.maven.lifecycle.internal.LifecycleStarter;
@@ -215,18 +214,18 @@ public class DefaultMaven implements Maven {
         // so that @SessionScoped components can be @Injected into AbstractLifecycleParticipants.
         //
         sessionScope.enter();
-        try (CloseableSession closeableSession = newCloseableSession(request)) {
+        MavenChainedWorkspaceReader chainedWorkspaceReader = new MavenChainedWorkspaceReader();
-            AtomicReference<CloseableSession> closeableSessionRef = new AtomicReference<>(closeableSession);
+        try (CloseableSession closeableSession = newCloseableSession(request, chainedWorkspaceReader)) {
-            MavenSession session = new MavenSession(closeableSessionRef::get, request, result);
+            MavenSession session = new MavenSession(closeableSession, request, result);
             session.setSession(defaultSessionFactory.getSession(session));
 
             sessionScope.seed(MavenSession.class, session);
             sessionScope.seed(Session.class, session.getSession());
-            sessionScope.seed(DefaultSession.class, (DefaultSession) session.getSession());
+            sessionScope.seed(InternalSession.class, InternalSession.from(session.getSession()));
 
             legacySupport.setSession(session);
 
-            return doExecute(request, session, result, closeableSessionRef);
+            return doExecute(request, session, result, chainedWorkspaceReader);
         } finally {
             sessionScope.exit();
         }
@@ -236,7 +235,7 @@ public class DefaultMaven implements Maven {
             MavenExecutionRequest request,
             MavenSession session,
             MavenExecutionResult result,
-            AtomicReference<CloseableSession> closeableSessionRef) {
+            MavenChainedWorkspaceReader chainedWorkspaceReader) {
         try {
             afterSessionStart(session);
         } catch (MavenExecutionException e) {
@@ -245,11 +244,7 @@ public class DefaultMaven implements Maven {
 
         try {
             WorkspaceReader reactorReader = container.lookup(WorkspaceReader.class, ReactorReader.HINT);
-            closeableSessionRef.set(closeableSessionRef
+            chainedWorkspaceReader.setReaders(Collections.singletonList(reactorReader));
-                    .get()
-                    .copy()
-                    .setWorkspaceReader(reactorReader)
-                    .build());
         } catch (ComponentLookupException e) {
             return addExceptionToResult(result, e);
         }
@@ -270,7 +265,7 @@ public class DefaultMaven implements Maven {
         }
 
         try {
-            closeableSessionRef.set(setupWorkspaceReader(session, closeableSessionRef.get()));
+            setupWorkspaceReader(session, chainedWorkspaceReader);
         } catch (ComponentLookupException e) {
             return addExceptionToResult(result, e);
         }
@@ -340,7 +335,7 @@ public class DefaultMaven implements Maven {
         return result;
     }
 
-    private CloseableSession setupWorkspaceReader(MavenSession session, CloseableSession repoSession)
+    private void setupWorkspaceReader(MavenSession session, MavenChainedWorkspaceReader chainedWorkspaceReader)
             throws ComponentLookupException {
         // Desired order of precedence for workspace readers before querying the local artifact repositories
         Set<WorkspaceReader> workspaceReaders = new LinkedHashSet<>();
@@ -348,16 +343,14 @@ public class DefaultMaven implements Maven {
         WorkspaceReader reactorReader = container.lookup(WorkspaceReader.class, ReactorReader.HINT);
         workspaceReaders.add(reactorReader);
         // 2) Repository system session-scoped workspace reader
-        WorkspaceReader repoWorkspaceReader = repoSession.getWorkspaceReader();
+        for (WorkspaceReader repoWorkspaceReader : chainedWorkspaceReader.getReaders()) {
             if (repoWorkspaceReader != null && repoWorkspaceReader != reactorReader) {
                 workspaceReaders.add(repoWorkspaceReader);
             }
+        }
         // 3) .. n) Project-scoped workspace readers
         workspaceReaders.addAll(getProjectScopedExtensionComponents(session.getProjects(), WorkspaceReader.class));
-        return repoSession
+        chainedWorkspaceReader.setReaders(workspaceReaders);
-                .copy()
-                .setWorkspaceReader(MavenChainedWorkspaceReader.of(workspaceReaders))
-                .build();
     }
 
     private void afterSessionStart(MavenSession session) throws MavenExecutionException {
@@ -418,11 +411,14 @@ public class DefaultMaven implements Maven {
      */
     @Deprecated
     public RepositorySystemSession newRepositorySession(MavenExecutionRequest request) {
-        return newCloseableSession(request);
+        return newCloseableSession(request, new MavenChainedWorkspaceReader());
     }
 
-    private CloseableSession newCloseableSession(MavenExecutionRequest request) {
+    private CloseableSession newCloseableSession(MavenExecutionRequest request, WorkspaceReader workspaceReader) {
-        return repositorySessionFactory.newRepositorySessionBuilder(request).build();
+        return repositorySessionFactory
+                .newRepositorySessionBuilder(request)
+                .setWorkspaceReader(workspaceReader)
+                .build();
     }
 
     private void validateLocalRepository(MavenExecutionRequest request) throws IOException {

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

@@ -27,7 +27,6 @@ import java.util.Map;
 import java.util.Properties;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
-import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
 import org.apache.maven.api.Session;
@@ -58,7 +57,7 @@ public class MavenSession implements Cloneable {
 
     private final MavenExecutionResult result;
 
-    private final Supplier<RepositorySystemSession> repositorySystemSessionSupplier;
+    private final RepositorySystemSession repositorySystemSession;
 
     private final Properties executionProperties;
 
@@ -260,7 +259,7 @@ public class MavenSession implements Cloneable {
     }
 
     public RepositorySystemSession getRepositorySession() {
-        return repositorySystemSessionSupplier.get();
+        return repositorySystemSession;
     }
 
     private Map<String, MavenProject> projectMap;
@@ -298,14 +297,14 @@ public class MavenSession implements Cloneable {
     }
 
     public MavenSession(
-            Supplier<RepositorySystemSession> repositorySystemSessionSupplier,
+            RepositorySystemSession repositorySystemSession,
             MavenExecutionRequest request,
             MavenExecutionResult result) {
         this.container = null;
         this.request = requireNonNull(request);
         this.result = requireNonNull(result);
         this.settings = adaptSettings(request);
-        this.repositorySystemSessionSupplier = requireNonNull(repositorySystemSessionSupplier);
+        this.repositorySystemSession = requireNonNull(repositorySystemSession);
         Properties executionProperties = new Properties();
         executionProperties.putAll(request.getSystemProperties());
         executionProperties.putAll(request.getUserProperties());
@@ -322,7 +321,7 @@ public class MavenSession implements Cloneable {
         this.request = request;
         this.result = result;
         this.settings = adaptSettings(request);
-        this.repositorySystemSessionSupplier = () -> repositorySession;
+        this.repositorySystemSession = repositorySession;
         Properties executionProperties = new Properties();
         executionProperties.putAll(request.getSystemProperties());
         executionProperties.putAll(request.getUserProperties());
@@ -386,7 +385,7 @@ public class MavenSession implements Cloneable {
         this.request.setBaseDirectory((executionRootDir != null) ? new File(executionRootDir) : null);
         this.request.setStartTime(startTime);
         this.result = null;
-        this.repositorySystemSessionSupplier = () -> null;
+        this.repositorySystemSession = null;
     }
 
     @Deprecated
@@ -404,7 +403,7 @@ public class MavenSession implements Cloneable {
         executionProperties.putAll(request.getUserProperties());
         this.executionProperties = executionProperties;
         setProjects(projects);
-        this.repositorySystemSessionSupplier = () -> null;
+        this.repositorySystemSession = null;
     }
 
     /**

maven-core/src/main/java/org/apache/maven/execution/scope/internal/MojoExecutionScopeModule.java

@@ -43,6 +43,7 @@ public class MojoExecutionScopeModule extends AbstractModule {
     @Override
     protected void configure() {
         bindScope(MojoExecutionScoped.class, scope);
+        bindScope(org.apache.maven.api.di.MojoExecutionScoped.class, scope);
         bind(MojoExecutionScope.class).toInstance(scope);
         bind(MavenProject.class)
                 .toProvider(MojoExecutionScope.seededKeyProvider())

maven-core/src/main/java/org/apache/maven/internal/aether/MavenChainedWorkspaceReader.java

@@ -19,61 +19,122 @@
 package org.apache.maven.internal.aether;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.apache.maven.model.Model;
 import org.apache.maven.repository.internal.MavenWorkspaceReader;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.repository.WorkspaceReader;
 import org.eclipse.aether.repository.WorkspaceRepository;
-import org.eclipse.aether.util.repository.ChainedWorkspaceReader;
+
+import static java.util.Objects.requireNonNull;
 
 /**
  * A maven workspace reader that delegates to a chain of other readers, effectively aggregating their contents.
  */
-public final class MavenChainedWorkspaceReader implements MavenWorkspaceReader {
+public class MavenChainedWorkspaceReader implements MavenWorkspaceReader {
 
-    private ChainedWorkspaceReader delegate;
+    protected List<WorkspaceReader> readers;
-
+    protected WorkspaceRepository repository;
-    private WorkspaceReader[] readers;
 
     /**
      * Creates a new workspace reader by chaining the specified readers.
      *
      * @param readers The readers to chain must not be {@code null}.
      */
-    private MavenChainedWorkspaceReader(WorkspaceReader... readers) {
+    public MavenChainedWorkspaceReader(WorkspaceReader... readers) {
-        this.delegate = new ChainedWorkspaceReader(readers);
+        setReaders(Arrays.asList(readers));
-        this.readers = readers;
-    }
-
-    @Override
-    public Model findModel(Artifact artifact) {
-        for (WorkspaceReader workspaceReader : readers) {
-            if (workspaceReader instanceof MavenWorkspaceReader) {
-                Model model = ((MavenWorkspaceReader) workspaceReader).findModel(artifact);
-                if (model != null) {
-                    return model;
-                }
-            }
-        }
-        return null;
     }
 
     @Override
     public WorkspaceRepository getRepository() {
-        return delegate.getRepository();
+        return this.repository;
+    }
+
+    @Override
+    public Model findModel(Artifact artifact) {
+        requireNonNull(artifact, "artifact cannot be null");
+        Model model = null;
+
+        for (WorkspaceReader workspaceReader : readers) {
+            if (workspaceReader instanceof MavenWorkspaceReader) {
+                model = ((MavenWorkspaceReader) workspaceReader).findModel(artifact);
+                if (model != null) {
+                    break;
+                }
+            }
+        }
+
+        return model;
     }
 
     @Override
     public File findArtifact(Artifact artifact) {
-        return delegate.findArtifact(artifact);
+        requireNonNull(artifact, "artifact cannot be null");
+        File file = null;
+
+        for (WorkspaceReader reader : readers) {
+            file = reader.findArtifact(artifact);
+            if (file != null) {
+                break;
+            }
+        }
+
+        return file;
     }
 
     @Override
     public List<String> findVersions(Artifact artifact) {
-        return delegate.findVersions(artifact);
+        requireNonNull(artifact, "artifact cannot be null");
+        Collection<String> versions = new LinkedHashSet<>();
+
+        for (WorkspaceReader reader : readers) {
+            versions.addAll(reader.findVersions(artifact));
+        }
+
+        return Collections.unmodifiableList(new ArrayList<>(versions));
+    }
+
+    public void setReaders(Collection<WorkspaceReader> readers) {
+        this.readers = Collections.unmodifiableList(new ArrayList<>(readers));
+        Key key = new Key(this.readers);
+        this.repository = new WorkspaceRepository(key.getContentType(), key);
+    }
+
+    public List<WorkspaceReader> getReaders() {
+        return readers;
+    }
+
+    private static class Key {
+        private final List<Object> keys;
+        private final String type;
+
+        Key(Collection<WorkspaceReader> readers) {
+            keys = readers.stream().map(r -> r.getRepository().getKey()).collect(Collectors.toList());
+            type = readers.stream().map(r -> r.getRepository().getContentType()).collect(Collectors.joining("+"));
+        }
+
+        public String getContentType() {
+            return type;
+        }
+
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            } else {
+                return obj != null && this.getClass().equals(obj.getClass()) && this.keys.equals(((Key) obj).keys);
+            }
+        }
+
+        public int hashCode() {
+            return this.keys.hashCode();
+        }
     }
 
     /**

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

@@ -66,7 +66,7 @@ import org.apache.maven.project.MavenProject;
 
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
-public abstract class AbstractSession implements Session {
+public abstract class AbstractSession implements InternalSession {
 
     private final List<Listener> listeners = new CopyOnWriteArrayList<>();
     private final Map<org.eclipse.aether.graph.DependencyNode, Node> allNodes =

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

@@ -31,11 +31,11 @@ import static org.apache.maven.internal.impl.Utils.nonNull;
  * A wrapper class around a maven resolver artifact.
  */
 public class DefaultArtifact implements Artifact {
-    private final @Nonnull AbstractSession session;
+    private final @Nonnull InternalSession session;
     private final @Nonnull org.eclipse.aether.artifact.Artifact artifact;
     private final String id;
 
-    public DefaultArtifact(@Nonnull AbstractSession session, @Nonnull org.eclipse.aether.artifact.Artifact artifact) {
+    public DefaultArtifact(@Nonnull InternalSession session, @Nonnull org.eclipse.aether.artifact.Artifact artifact) {
         this.session = nonNull(session, "session can not be null");
         this.artifact = nonNull(artifact, "artifact can not be null");
         this.id = getGroupId()

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

@@ -30,11 +30,11 @@ import static org.apache.maven.internal.impl.Utils.nonNull;
  * A wrapper class around a maven resolver artifact.
  */
 public class DefaultArtifactCoordinate implements ArtifactCoordinate {
-    private final @Nonnull AbstractSession session;
+    private final @Nonnull InternalSession session;
     private final @Nonnull org.eclipse.aether.artifact.Artifact coordinate;
 
     public DefaultArtifactCoordinate(
-            @Nonnull AbstractSession session, @Nonnull org.eclipse.aether.artifact.Artifact coordinate) {
+            @Nonnull InternalSession session, @Nonnull org.eclipse.aether.artifact.Artifact coordinate) {
         this.session = nonNull(session, "session can not be null");
         this.coordinate = nonNull(coordinate, "coordinate can not be null");
     }

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

@@ -27,7 +27,6 @@ import org.apache.maven.api.services.ArtifactCoordinateFactory;
 import org.apache.maven.api.services.ArtifactCoordinateFactoryRequest;
 import org.eclipse.aether.artifact.ArtifactType;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -36,8 +35,7 @@ public class DefaultArtifactCoordinateFactory implements ArtifactCoordinateFacto
     @Override
     public ArtifactCoordinate create(@Nonnull ArtifactCoordinateFactoryRequest request) {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
         ArtifactType type = null;
         if (request.getType() != null) {
             type = session.getSession().getArtifactTypeRegistry().get(request.getType());

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

@@ -35,7 +35,6 @@ import org.eclipse.aether.deployment.DeployRequest;
 import org.eclipse.aether.deployment.DeployResult;
 import org.eclipse.aether.deployment.DeploymentException;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 /**
@@ -54,8 +53,7 @@ public class DefaultArtifactDeployer implements ArtifactDeployer {
     @Override
     public void deploy(@Nonnull ArtifactDeployerRequest request) {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
         Collection<Artifact> artifacts = nonNull(request.getArtifacts(), "request.artifacts can not be null");
         RemoteRepository repository = nonNull(request.getRepository(), "request.repository can not be null");
         try {

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

@@ -27,7 +27,6 @@ import org.apache.maven.api.services.ArtifactFactory;
 import org.apache.maven.api.services.ArtifactFactoryRequest;
 import org.eclipse.aether.artifact.ArtifactType;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -36,8 +35,7 @@ public class DefaultArtifactFactory implements ArtifactFactory {
     @Override
     public Artifact create(@Nonnull ArtifactFactoryRequest request) {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
         ArtifactType type = null;
         if (request.getType() != null) {
             type = session.getSession().getArtifactTypeRegistry().get(request.getType());

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

@@ -31,7 +31,6 @@ import org.eclipse.aether.installation.InstallRequest;
 import org.eclipse.aether.installation.InstallResult;
 import org.eclipse.aether.installation.InstallationException;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -48,8 +47,7 @@ public class DefaultArtifactInstaller implements ArtifactInstaller {
     @Override
     public void install(ArtifactInstallerRequest request) throws ArtifactInstallerException, IllegalArgumentException {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
         try {
             InstallRequest installRequest =
                     new InstallRequest().setArtifacts(session.toArtifacts(request.getArtifacts()));

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

@@ -24,26 +24,30 @@ import javax.inject.Named;
 import java.io.File;
 import java.nio.file.Path;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Stream;
 
-import org.apache.maven.SessionScoped;
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.SessionScoped;
 import org.apache.maven.api.services.ArtifactManager;
 import org.apache.maven.project.MavenProject;
+import org.eclipse.sisu.Typed;
 
 @Named
+@Typed
 @SessionScoped
 public class DefaultArtifactManager implements ArtifactManager {
 
     @Nonnull
-    private final DefaultSession session;
+    private final InternalSession session;
 
     private final Map<String, Path> paths = new ConcurrentHashMap<>();
 
     @Inject
-    public DefaultArtifactManager(@Nonnull DefaultSession session) {
+    public DefaultArtifactManager(@Nonnull InternalSession session) {
         this.session = session;
     }
 
@@ -73,12 +77,10 @@ public class DefaultArtifactManager implements ArtifactManager {
     public void setPath(@Nonnull Artifact artifact, Path path) {
         String id = id(artifact);
         if (session.getMavenSession().getAllProjects() != null) {
-            for (MavenProject project : session.getMavenSession().getAllProjects()) {
+            session.getMavenSession().getAllProjects().stream()
-                if (id.equals(id(project.getArtifact()))) {
+                    .flatMap(this::getProjectArtifacts)
-                    project.getArtifact().setFile(path != null ? path.toFile() : null);
+                    .filter(a -> Objects.equals(id, id(a)))
-                    break;
+                    .forEach(a -> a.setFile(path != null ? path.toFile() : null));
-                }
-            }
         }
         if (path == null) {
             paths.remove(id);
@@ -87,10 +89,18 @@ public class DefaultArtifactManager implements ArtifactManager {
         }
     }
 
+    /**
+     * Retrieve a stream of the project's artifacts.
+     * Do not include the POM artifact as the file can't be set anyway.
+     */
+    private Stream<org.apache.maven.artifact.Artifact> getProjectArtifacts(MavenProject project) {
+        return Stream.concat(Stream.of(project.getArtifact()), project.getAttachedArtifacts().stream());
+    }
+
     private String id(org.apache.maven.artifact.Artifact artifact) {
         return artifact.getGroupId()
                 + ":" + artifact.getArtifactId()
-                + ":" + artifact.getType()
+                + ":" + artifact.getArtifactHandler().getExtension()
                 + (artifact.getClassifier() == null || artifact.getClassifier().isEmpty()
                         ? ""
                         : ":" + artifact.getClassifier())

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

@@ -23,12 +23,13 @@ import javax.inject.Named;
 import javax.inject.Singleton;
 
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Collectors;
 
 import org.apache.maven.api.Artifact;
+import org.apache.maven.api.ArtifactCoordinate;
 import org.apache.maven.api.annotations.Nonnull;
 import org.apache.maven.api.services.ArtifactManager;
 import org.apache.maven.api.services.ArtifactResolver;
@@ -41,7 +42,6 @@ import org.eclipse.aether.resolution.ArtifactRequest;
 import org.eclipse.aether.resolution.ArtifactResolutionException;
 import org.eclipse.aether.resolution.ArtifactResult;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -58,27 +58,32 @@ public class DefaultArtifactResolver implements ArtifactResolver {
     public ArtifactResolverResult resolve(ArtifactResolverRequest request)
             throws ArtifactResolverException, IllegalArgumentException {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
         try {
-            List<RemoteRepository> repositories = session.toRepositories(session.getRemoteRepositories());
-            List<ArtifactRequest> requests = request.getCoordinates().stream()
-                    .map(coord -> new ArtifactRequest(session.toArtifact(coord), repositories, null))
-                    .collect(Collectors.toList());
-            List<ArtifactResult> results = repositorySystem.resolveArtifacts(session.getSession(), requests);
             Map<Artifact, Path> paths = new HashMap<>();
+            ArtifactManager artifactManager = session.getService(ArtifactManager.class);
+            List<RemoteRepository> repositories = session.toRepositories(session.getRemoteRepositories());
+            List<ArtifactRequest> requests = new ArrayList<>();
+            for (ArtifactCoordinate coord : request.getCoordinates()) {
+                org.eclipse.aether.artifact.Artifact aetherArtifact = session.toArtifact(coord);
+                Artifact artifact = session.getArtifact(aetherArtifact);
+                Path path = artifactManager.getPath(artifact).orElse(null);
+                if (path != null) {
+                    paths.put(artifact, path);
+                } else {
+                    requests.add(new ArtifactRequest(aetherArtifact, repositories, null));
+                }
+            }
+            if (!requests.isEmpty()) {
+                List<ArtifactResult> results = repositorySystem.resolveArtifacts(session.getSession(), requests);
                 for (ArtifactResult result : results) {
                     Artifact artifact = session.getArtifact(result.getArtifact());
                     Path path = result.getArtifact().getFile().toPath();
-                session.getService(ArtifactManager.class).setPath(artifact, path);
+                    artifactManager.setPath(artifact, path);
                     paths.put(artifact, path);
                 }
-            return new ArtifactResolverResult() {
-                @Override
-                public Map<Artifact, Path> getArtifacts() {
-                    return paths;
             }
-            };
+            return () -> paths;
         } catch (ArtifactResolutionException e) {
             throw new ArtifactResolverException("Unable to resolve artifact", e);
         }

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

@@ -34,13 +34,13 @@ import org.eclipse.aether.artifact.ArtifactProperties;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 public class DefaultDependency implements Dependency {
-    private final AbstractSession session;
+    private final InternalSession session;
     private final org.eclipse.aether.graph.Dependency dependency;
     private final DependencyProperties dependencyProperties;
     private final String key;
 
     public DefaultDependency(
-            @Nonnull AbstractSession session, @Nonnull org.eclipse.aether.graph.Dependency dependency) {
+            @Nonnull InternalSession session, @Nonnull org.eclipse.aether.graph.Dependency dependency) {
         this.session = nonNull(session, "session");
         this.dependency = nonNull(dependency, "dependency");
         this.dependencyProperties =
@@ -50,7 +50,7 @@ public class DefaultDependency implements Dependency {
                 + getArtifactId()
                 + ':'
                 + getExtension()
-                + (getClassifier().length() > 0 ? ":" + getClassifier() : "")
+                + (!getClassifier().isEmpty() ? ":" + getClassifier() : "")
                 + ':'
                 + getVersion();
     }

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

@@ -41,7 +41,6 @@ import org.eclipse.aether.graph.Dependency;
 import org.eclipse.aether.util.graph.manager.DependencyManagerUtils;
 import org.eclipse.aether.util.graph.transformer.ConflictResolver;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -60,8 +59,7 @@ public class DefaultDependencyCollector implements DependencyCollector {
     public DependencyCollectorResult collect(@Nonnull DependencyCollectorRequest request)
             throws DependencyCollectorException, IllegalArgumentException {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
 
         Artifact rootArtifact =
                 request.getRootArtifact().map(session::toArtifact).orElse(null);

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

@@ -33,11 +33,11 @@ import org.eclipse.aether.artifact.ArtifactProperties;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 public class DefaultDependencyCoordinate implements DependencyCoordinate {
-    private final AbstractSession session;
+    private final InternalSession session;
     private final org.eclipse.aether.graph.Dependency dependency;
 
     public DefaultDependencyCoordinate(
-            @Nonnull AbstractSession session, @Nonnull org.eclipse.aether.graph.Dependency dependency) {
+            @Nonnull InternalSession session, @Nonnull org.eclipse.aether.graph.Dependency dependency) {
         this.session = nonNull(session, "session");
         this.dependency = nonNull(dependency, "dependency");
     }

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

@@ -30,7 +30,6 @@ import org.apache.maven.api.services.DependencyCoordinateFactory;
 import org.apache.maven.api.services.DependencyCoordinateFactoryRequest;
 import org.eclipse.aether.artifact.ArtifactType;
 
-import static org.apache.maven.internal.impl.Utils.cast;
 import static org.apache.maven.internal.impl.Utils.nonNull;
 
 @Named
@@ -41,8 +40,7 @@ public class DefaultDependencyCoordinateFactory implements DependencyCoordinateF
     @Override
     public DependencyCoordinate create(@Nonnull DependencyCoordinateFactoryRequest request) {
         nonNull(request, "request can not be null");
-        DefaultSession session =
+        InternalSession session = InternalSession.from(request.getSession());
-                cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
 
         ArtifactType type = null;
         if (request.getType() != null) {

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 AbstractSession session;
+    private final InternalSession session;
     private final ExecutionEvent delegate;
 
-    public DefaultEvent(AbstractSession session, ExecutionEvent delegate) {
+    public DefaultEvent(InternalSession session, ExecutionEvent delegate) {
         this.session = session;
         this.delegate = delegate;
     }
@@ -53,11 +53,11 @@ public class DefaultEvent implements Event {
 
     @Override
     public Optional<MojoExecution> getMojoExecution() {
-        return Optional.ofNullable(delegate.getMojoExecution()).map(DefaultMojoExecution::new);
+        return Optional.ofNullable(delegate.getMojoExecution()).map(me -> new DefaultMojoExecution(session, me));
     }
 
     @Override
     public Optional<Exception> getException() {
-        return Optional.empty();
+        return Optional.ofNullable(delegate.getException());
     }
 }

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

@@ -35,7 +35,7 @@ public class DefaultLocalRepositoryManager implements LocalRepositoryManager {
 
     @Override
     public Path getPathForLocalArtifact(Session session, LocalRepository local, Artifact artifact) {
-        DefaultSession s = (DefaultSession) session;
+        InternalSession s = InternalSession.from(session);
         String path = getManager(s, local).getPathForLocalArtifact(s.toArtifact(artifact));
         return local.getPath().resolve(path);
     }
@@ -43,14 +43,14 @@ public class DefaultLocalRepositoryManager implements LocalRepositoryManager {
     @Override
     public Path getPathForRemoteArtifact(
             Session session, LocalRepository local, RemoteRepository remote, Artifact artifact) {
-        DefaultSession s = (DefaultSession) session;
+        InternalSession s = InternalSession.from(session);
         String path =
                 getManager(s, local).getPathForRemoteArtifact(s.toArtifact(artifact), s.toRepository(remote), null);
         return local.getPath().resolve(path);
     }
 
     private org.eclipse.aether.repository.LocalRepositoryManager getManager(
-            DefaultSession session, LocalRepository local) {
+            InternalSession session, LocalRepository local) {
         org.eclipse.aether.repository.LocalRepository repository = session.toRepository(local);
         if ("enhanced".equals(repository.getContentType())) {
             repository = new org.eclipse.aether.repository.LocalRepository(repository.getBasedir(), "");

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

@@ -18,17 +18,34 @@
  */
 package org.apache.maven.internal.impl;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
+import java.util.stream.Collectors;
 
+import org.apache.maven.RepositoryUtils;
+import org.apache.maven.api.Artifact;
+import org.apache.maven.api.Dependency;
 import org.apache.maven.api.MojoExecution;
-import org.apache.maven.api.model.Plugin;
+import org.apache.maven.api.Node;
+import org.apache.maven.api.Plugin;
+import org.apache.maven.api.model.PluginExecution;
+import org.apache.maven.api.plugin.descriptor.MojoDescriptor;
+import org.apache.maven.api.plugin.descriptor.PluginDescriptor;
+import org.apache.maven.api.plugin.descriptor.lifecycle.Lifecycle;
 import org.apache.maven.api.xml.XmlNode;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
+import org.eclipse.aether.graph.DependencyNode;
 
 public class DefaultMojoExecution implements MojoExecution {
+    private final InternalSession session;
     private final org.apache.maven.plugin.MojoExecution delegate;
 
-    public DefaultMojoExecution(org.apache.maven.plugin.MojoExecution delegate) {
+    public DefaultMojoExecution(InternalSession session, org.apache.maven.plugin.MojoExecution delegate) {
+        this.session = session;
         this.delegate = delegate;
     }
 
@@ -38,9 +55,73 @@ public class DefaultMojoExecution implements MojoExecution {
 
     @Override
     public Plugin getPlugin() {
+        return new Plugin() {
+            @Override
+            public org.apache.maven.api.model.Plugin getModel() {
                 return delegate.getPlugin().getDelegate();
             }
 
+            @Override
+            public PluginDescriptor getDescriptor() {
+                return delegate.getMojoDescriptor().getPluginDescriptor().getPluginDescriptorV4();
+            }
+
+            @Override
+            public List<Lifecycle> getLifecycles() {
+                try {
+                    return Collections.unmodifiableList(new ArrayList<>(delegate.getMojoDescriptor()
+                            .getPluginDescriptor()
+                            .getLifecycleMappings()
+                            .values()));
+                } catch (Exception e) {
+                    throw new RuntimeException("Unable to load plugin lifecycles", e);
+                }
+            }
+
+            @Override
+            public ClassLoader getClassLoader() {
+                return delegate.getMojoDescriptor().getRealm();
+            }
+
+            @Override
+            public Artifact getArtifact() {
+                org.apache.maven.artifact.Artifact artifact =
+                        delegate.getMojoDescriptor().getPluginDescriptor().getPluginArtifact();
+                org.eclipse.aether.artifact.Artifact resolverArtifact = RepositoryUtils.toArtifact(artifact);
+                return resolverArtifact != null ? session.getArtifact(resolverArtifact) : null;
+            }
+
+            @Override
+            public Map<String, Dependency> getDependenciesMap() {
+                DependencyNode resolverNode =
+                        delegate.getMojoDescriptor().getPluginDescriptor().getDependencyNode();
+                DefaultNode node = new DefaultNode(session, resolverNode, false);
+                return Collections.unmodifiableMap(node.stream()
+                        .map(Node::getDependency)
+                        .collect(Collectors.toMap(d -> d.getGroupId() + ":" + d.getArtifactId(), d -> d)));
+            }
+        };
+    }
+
+    @Override
+    public PluginExecution getModel() {
+        return delegate.getPlugin().getExecutions().stream()
+                .filter(pe -> Objects.equals(pe.getId(), getExecutionId()))
+                .findFirst()
+                .map(org.apache.maven.model.PluginExecution::getDelegate)
+                .orElse(null);
+    }
+
+    @Override
+    public MojoDescriptor getDescriptor() {
+        return delegate.getMojoDescriptor().getMojoDescriptorV4();
+    }
+
+    @Override
+    public String getLifecyclePhase() {
+        return delegate.getLifecyclePhase();
+    }
+
     @Override
     public String getExecutionId() {
         return delegate.getExecutionId();

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

@@ -33,12 +33,12 @@ import org.eclipse.aether.util.graph.transformer.ConflictResolver;
 
 public class DefaultNode extends AbstractNode {
 
-    protected final @Nonnull AbstractSession session;
+    protected final @Nonnull InternalSession session;
     protected final @Nonnull org.eclipse.aether.graph.DependencyNode node;
     protected final boolean verbose;
 
     public DefaultNode(
-            @Nonnull AbstractSession session, @Nonnull org.eclipse.aether.graph.DependencyNode node, boolean verbose) {
+            @Nonnull InternalSession session, @Nonnull org.eclipse.aether.graph.DependencyNode node, boolean verbose) {
         this.session = session;
         this.node = node;
         this.verbose = verbose;
@@ -66,7 +66,7 @@ public class DefaultNode extends AbstractNode {
 
     @Override
     public Optional<RemoteRepository> getRepository() {
-        // TODO
+        // TODO: v4: implement
         throw new UnsupportedOperationException("Not implemented yet");
     }
 

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

@@ -44,15 +44,15 @@ import org.apache.maven.project.MavenProject;
 
 public class DefaultProject implements Project {
 
-    private final AbstractSession session;
+    private final InternalSession session;
     private final MavenProject project;
 
-    public DefaultProject(AbstractSession session, MavenProject project) {
+    public DefaultProject(InternalSession session, MavenProject project) {
         this.session = session;
         this.project = project;
     }
 
-    public AbstractSession getSession() {
+    public InternalSession getSession() {
         return session;
     }
 

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

@@ -69,7 +69,7 @@ public class DefaultProjectBuilder implements ProjectBuilder {
     @Override
     public ProjectBuilderResult build(ProjectBuilderRequest request)
             throws ProjectBuilderException, IllegalArgumentException {
-        DefaultSession session = (DefaultSession) request.getSession();
+        InternalSession session = InternalSession.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

@@ -30,7 +30,6 @@ import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.apache.maven.RepositoryUtils;
-import org.apache.maven.SessionScoped;
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.Node;
 import org.apache.maven.api.Project;
@@ -39,6 +38,7 @@ import org.apache.maven.api.ResolutionScope;
 import org.apache.maven.api.Scope;
 import org.apache.maven.api.Session;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.di.SessionScoped;
 import org.apache.maven.api.services.ArtifactManager;
 import org.apache.maven.api.services.MavenException;
 import org.apache.maven.api.services.ProjectManager;
@@ -47,8 +47,10 @@ import org.apache.maven.lifecycle.internal.LifecycleDependencyResolver;
 import org.apache.maven.project.MavenProject;
 import org.codehaus.plexus.PlexusContainer;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
+import org.eclipse.sisu.Typed;
 
 @Named
+@Typed
 @SessionScoped
 public class DefaultProjectManager implements ProjectManager {
 
@@ -73,7 +75,7 @@ public class DefaultProjectManager implements ProjectManager {
     @Nonnull
     @Override
     public Collection<Artifact> getAttachedArtifacts(Project project) {
-        AbstractSession session = ((DefaultProject) project).getSession();
+        InternalSession session = ((DefaultProject) project).getSession();
         Collection<Artifact> attached = getMavenProject(project).getAttachedArtifacts().stream()
                 .map(RepositoryUtils::toArtifact)
                 .map(session::getArtifact)
@@ -129,12 +131,12 @@ public class DefaultProjectManager implements ProjectManager {
                     getMavenProject(project),
                     toResolve,
                     toResolve,
-                    ((DefaultSession) session).getMavenSession(),
+                    InternalSession.from(session).getMavenSession(),
                     false,
                     Collections.emptySet());
             return artifacts.stream()
                     .map(RepositoryUtils::toArtifact)
-                    .map(((DefaultSession) session)::getArtifact)
+                    .map(InternalSession.from(session)::getArtifact)
                     .collect(Collectors.toList());
         } catch (LifecycleExecutionException | ComponentLookupException e) {
             throw new MavenException("Unable to resolve project dependencies", e);

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

@@ -21,11 +21,11 @@ package org.apache.maven.internal.impl;
 import java.nio.file.Path;
 import java.time.Instant;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
@@ -65,7 +65,7 @@ public class DefaultSession extends AbstractSession {
     private final MavenRepositorySystem mavenRepositorySystem;
     private final PlexusContainer container;
     private final RuntimeInformation runtimeInformation;
-    private final Map<Class<? extends Service>, Service> services = new HashMap<>();
+    private final Map<Class<? extends Service>, Service> services = new ConcurrentHashMap<>();
 
     @SuppressWarnings("checkstyle:ParameterNumber")
     public DefaultSession(
@@ -213,8 +213,7 @@ public class DefaultSession extends AbstractSession {
 
         RepositorySystemSession repoSession =
                 new DefaultRepositorySystemSession(session).setLocalRepositoryManager(localRepositoryManager);
-        MavenSession newSession =
+        MavenSession newSession = new MavenSession(repoSession, mavenSession.getRequest(), mavenSession.getResult());
-                new MavenSession(() -> repoSession, mavenSession.getRequest(), mavenSession.getResult());
         return new DefaultSession(
                 newSession, repositorySystem, repositories, mavenRepositorySystem, container, runtimeInformation);
     }

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(DefaultSession.class, () -> newSession(mavenSession));
+        return (Session) data.computeIfAbsent(InternalSession.class, () -> newSession(mavenSession));
     }
 
     private Session newSession(MavenSession mavenSession) {

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

@@ -57,7 +57,7 @@ public class DefaultSettingsBuilder implements SettingsBuilder {
     @Override
     public SettingsBuilderResult build(SettingsBuilderRequest request)
             throws SettingsBuilderException, IllegalArgumentException {
-        DefaultSession session = (DefaultSession) request.getSession();
+        InternalSession session = InternalSession.from(request.getSession());
         try {
             DefaultSettingsBuildingRequest req = new DefaultSettingsBuildingRequest();
             req.setUserProperties(toProperties(session.getUserProperties()));

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 = ((DefaultSession) session).getMavenSession();
+        MavenSession s = InternalSession.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 = ((DefaultSession) session).getMavenSession();
+        MavenSession s = InternalSession.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 = ((DefaultSession) session).getMavenSession();
+            MavenSession s = InternalSession.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 = ((DefaultSession) session).getMavenSession();
+        MavenSession s = InternalSession.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/DefaultTransportProvider.java

@@ -52,7 +52,7 @@ public class DefaultTransportProvider implements TransportProvider {
             return new DefaultTransport(
                     baseURI,
                     transporterProvider.newTransporter(
-                            ((DefaultSession) session).getSession(),
+                            InternalSession.from(session).getSession(),
                             ((DefaultRemoteRepository) repository).getRepository()));
         } catch (URISyntaxException e) {
             throw new TransportProviderException("Remote repository URL invalid", e);

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;
-            AbstractSession session = (AbstractSession) sessionFactory.getSession(ee.getSession());
+            InternalSession session = InternalSession.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/InternalSession.java

@@ -0,0 +1,88 @@
+/*
+ * 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.Collection;
+import java.util.List;
+
+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.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;
+
+import static org.apache.maven.internal.impl.Utils.cast;
+
+public interface InternalSession extends Session {
+
+    static InternalSession from(Session session) {
+        return cast(InternalSession.class, session, "session should be an " + InternalSession.class);
+    }
+
+    RemoteRepository getRemoteRepository(org.eclipse.aether.repository.RemoteRepository repository);
+
+    Node getNode(org.eclipse.aether.graph.DependencyNode node);
+
+    Node getNode(org.eclipse.aether.graph.DependencyNode node, boolean verbose);
+
+    @Nonnull
+    Artifact getArtifact(@Nonnull org.eclipse.aether.artifact.Artifact artifact);
+
+    @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);
+
+    org.eclipse.aether.graph.Dependency toDependency(DependencyCoordinate dependency);
+
+    List<org.eclipse.aether.artifact.Artifact> toArtifacts(Collection<Artifact> artifacts);
+
+    org.eclipse.aether.artifact.Artifact toArtifact(Artifact artifact);
+
+    org.eclipse.aether.artifact.Artifact toArtifact(ArtifactCoordinate coord);
+
+    MavenSession getMavenSession();
+
+    RepositorySystemSession getSession();
+
+    RepositorySystem getRepositorySystem();
+}

maven-core/src/main/java/org/apache/maven/lifecycle/internal/DefaultLifecycleExecutionPlanCalculator.java

@@ -24,16 +24,10 @@ import javax.inject.Singleton;
 import javax.xml.stream.XMLStreamException;
 
 import java.io.IOException;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
 
+import org.apache.maven.api.plugin.descriptor.lifecycle.Execution;
+import org.apache.maven.api.plugin.descriptor.lifecycle.Phase;
 import org.apache.maven.api.xml.XmlNode;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.internal.xml.XmlNodeImpl;
@@ -55,8 +49,6 @@ import org.apache.maven.plugin.PluginResolutionException;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.plugin.descriptor.Parameter;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
-import org.apache.maven.plugin.lifecycle.Execution;
-import org.apache.maven.plugin.lifecycle.Phase;
 import org.apache.maven.plugin.prefix.NoPluginFoundForPrefixException;
 import org.apache.maven.plugin.version.PluginVersionResolutionException;
 import org.apache.maven.project.MavenProject;
@@ -340,8 +332,12 @@ public class DefaultLifecycleExecutionPlanCalculator implements LifecycleExecuti
     }
 
     private XmlNode getMojoConfiguration(MojoDescriptor mojoDescriptor) {
+        if (mojoDescriptor.isV4Api()) {
+            return MojoDescriptorCreator.convert(mojoDescriptor.getMojoDescriptorV4());
+        } else {
             return MojoDescriptorCreator.convert(mojoDescriptor).getDom();
         }
+    }
 
     @Override
     public void calculateForkedExecutions(MojoExecution mojoExecution, MavenSession session)
@@ -459,7 +455,7 @@ public class DefaultLifecycleExecutionPlanCalculator implements LifecycleExecuti
             return;
         }
 
-        org.apache.maven.plugin.lifecycle.Lifecycle lifecycleOverlay;
+        org.apache.maven.api.plugin.descriptor.lifecycle.Lifecycle lifecycleOverlay;
 
         try {
             lifecycleOverlay = pluginDescriptor.getLifecycleMapping(forkedLifecycle);
@@ -491,7 +487,7 @@ public class DefaultLifecycleExecutionPlanCalculator implements LifecycleExecuti
                         MojoExecution forkedExecution =
                                 new MojoExecution(forkedMojoDescriptor, mojoExecution.getExecutionId());
 
-                        XmlNodeImpl forkedConfiguration = (XmlNodeImpl) execution.getConfiguration();
+                        XmlNode forkedConfiguration = execution.getConfiguration();
 
                         forkedExecution.setConfiguration(forkedConfiguration);
 
@@ -501,7 +497,7 @@ public class DefaultLifecycleExecutionPlanCalculator implements LifecycleExecuti
                     }
                 }
 
-                XmlNodeImpl phaseConfiguration = (XmlNodeImpl) phase.getConfiguration();
+                XmlNode phaseConfiguration = phase.getConfiguration();
 
                 if (phaseConfiguration != null) {
                     for (MojoExecution forkedExecution : forkedExecutions) {

maven-core/src/main/java/org/apache/maven/lifecycle/internal/MojoDescriptorCreator.java

@@ -26,6 +26,7 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.apache.maven.api.xml.XmlNode;
 import org.apache.maven.execution.MavenSession;
@@ -91,6 +92,21 @@ public class MojoDescriptorCreator {
         return null;
     }
 
+    public static XmlNode convert(org.apache.maven.api.plugin.descriptor.MojoDescriptor mojoDescriptor) {
+        List<XmlNode> children = mojoDescriptor.getParameters().stream()
+                .filter(p -> p.getDefaultValue() != null || p.getExpression() != null)
+                .map(p -> new XmlNodeImpl(
+                        p.getName(),
+                        p.getExpression(),
+                        p.getDefaultValue() != null
+                                ? Collections.singletonMap("default-value", p.getDefaultValue())
+                                : null,
+                        null,
+                        null))
+                .collect(Collectors.toList());
+        return new XmlNodeImpl("configuration", null, null, children, null);
+    }
+
     public static org.codehaus.plexus.util.xml.Xpp3Dom convert(MojoDescriptor mojoDescriptor) {
         PlexusConfiguration c = mojoDescriptor.getMojoConfiguration();
 

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.DefaultSession;
+import org.apache.maven.internal.impl.InternalSession;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
@@ -121,8 +121,9 @@ public class DefaultBuildPluginManager implements BuildPluginManager {
                     org.apache.maven.api.plugin.Log.class,
                     new DefaultLog(LoggerFactory.getLogger(
                             mojoExecution.getMojoDescriptor().getFullGoalName())));
-            scope.seed(Project.class, ((DefaultSession) session.getSession()).getProject(project));
+            InternalSession sessionV4 = InternalSession.from(session.getSession());
-            scope.seed(org.apache.maven.api.MojoExecution.class, new DefaultMojoExecution(mojoExecution));
+            scope.seed(Project.class, sessionV4.getProject(project));
+            scope.seed(org.apache.maven.api.MojoExecution.class, new DefaultMojoExecution(sessionV4, mojoExecution));
 
             if (mojoDescriptor.isV4Api()) {
                 org.apache.maven.api.plugin.Mojo mojoV4 = mavenPluginManager.getConfiguredMojo(

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

@@ -28,11 +28,8 @@ import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.maven.RepositoryUtils;
-import org.apache.maven.artifact.ArtifactUtils;
 import org.apache.maven.model.Plugin;
-import org.apache.maven.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
-import org.codehaus.plexus.component.repository.ComponentDescriptor;
 import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.repository.LocalRepository;
 import org.eclipse.aether.repository.RemoteRepository;
@@ -97,49 +94,7 @@ public class DefaultPluginDescriptorCache implements PluginDescriptorCache {
     }
 
     protected static PluginDescriptor clone(PluginDescriptor original) {
-        PluginDescriptor clone = null;
+        return new PluginDescriptor(original);
-
-        if (original != null) {
-            clone = new PluginDescriptor();
-
-            clone.setGroupId(original.getGroupId());
-            clone.setArtifactId(original.getArtifactId());
-            clone.setVersion(original.getVersion());
-            clone.setGoalPrefix(original.getGoalPrefix());
-            clone.setInheritedByDefault(original.isInheritedByDefault());
-
-            clone.setName(original.getName());
-            clone.setDescription(original.getDescription());
-            clone.setRequiredMavenVersion(original.getRequiredMavenVersion());
-            clone.setRequiredJavaVersion(original.getRequiredJavaVersion());
-
-            clone.setPluginArtifact(ArtifactUtils.copyArtifactSafe(original.getPluginArtifact()));
-
-            clone.setComponents(clone(original.getMojos(), clone));
-            clone.setId(original.getId());
-            clone.setIsolatedRealm(original.isIsolatedRealm());
-            clone.setSource(original.getSource());
-
-            clone.setDependencies(original.getDependencies());
-        }
-
-        return clone;
-    }
-
-    private static List<ComponentDescriptor<?>> clone(List<MojoDescriptor> mojos, PluginDescriptor pluginDescriptor) {
-        List<ComponentDescriptor<?>> clones = null;
-
-        if (mojos != null) {
-            clones = new ArrayList<>(mojos.size());
-
-            for (MojoDescriptor mojo : mojos) {
-                MojoDescriptor clone = mojo.clone();
-                clone.setPluginDescriptor(pluginDescriptor);
-                clones.add(clone);
-            }
-        }
-
-        return clones;
     }
 
     private static final class CacheKey implements Key {

maven-core/src/main/java/org/apache/maven/plugin/PluginParameterExpressionEvaluatorV4.java

@@ -21,16 +21,15 @@ package org.apache.maven.plugin;
 import java.io.File;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Properties;
 
+import org.apache.maven.api.MojoExecution;
 import org.apache.maven.api.Project;
 import org.apache.maven.api.Session;
-import org.apache.maven.internal.impl.DefaultMojoExecution;
-import org.apache.maven.internal.impl.DefaultSession;
 import org.apache.maven.model.interpolation.reflection.ReflectionValueExtractor;
-import org.apache.maven.plugin.descriptor.MojoDescriptor;
-import org.apache.maven.plugin.descriptor.PluginDescriptor;
 import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
 import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;
 
@@ -40,36 +39,18 @@ import org.codehaus.plexus.component.configurator.expression.TypeAwareExpression
  * <table border="1">
  * <caption>Expression matrix</caption>
  * <tr><th>expression</th>                     <th></th>               <th>evaluation result</th></tr>
- * <tr><td><code>session</code></td>           <td></td>               <td>the actual {@link Session}</td></tr>
+ * <tr><td><code>session.*</code></td>         <td></td>               <td></td></tr>
- * <tr><td><code>session.*</code></td>         <td>(since Maven 3)</td><td></td></tr>
- * <tr><td><code>localRepository</code></td>   <td></td>
- *                                             <td>{@link Session#getLocalRepository()}</td></tr>
- * <tr><td><code>reactorProjects</code></td>   <td></td>               <td>{@link Session#getProjects()}</td></tr>
- * <tr><td><code>project</code></td>           <td></td>
- *                                 <td>{@link org.apache.maven.execution.MavenSession#getCurrentProject()}</td></tr>
  * <tr><td><code>project.*</code></td>         <td></td>               <td></td></tr>
- * <tr><td><code>pom.*</code></td>             <td>(since Maven 3)</td><td>same as <code>project.*</code></td></tr>
- * <tr><td><code>executedProject</code></td>   <td></td>
- *                                 <td>{@link org.apache.maven.project.MavenProject#getExecutionProject()}</td></tr>
- * <tr><td><code>settings</code></td>          <td></td>               <td>{@link Session#getSettings()}</td></tr>
  * <tr><td><code>settings.*</code></td>        <td></td>               <td></td></tr>
- * <tr><td><code>basedir</code></td>           <td></td>
+ * <tr><td><code>mojo.*</code></td>            <td></td>               <td>the actual {@link MojoExecution}</td></tr>
- *                                 <td>{@link Session#getTopDirectory()} or
- *                                                 <code>System.getProperty( "user.dir" )</code> if null</td></tr>
- * <tr><td><code>mojoExecution</code></td>     <td></td>               <td>the actual {@link MojoExecution}</td></tr>
- * <tr><td><code>mojo</code></td>              <td>(since Maven 3)</td><td>same as <code>mojoExecution</code></td></tr>
- * <tr><td><code>mojo.*</code></td>            <td>(since Maven 3)</td><td></td></tr>
- * <tr><td><code>plugin</code></td>            <td>(since Maven 3)</td>
- *                             <td>{@link MojoExecution#getMojoDescriptor()}.{@link MojoDescriptor#getPluginDescriptor()
- *                                 getPluginDescriptor()}</td></tr>
- * <tr><td><code>plugin.*</code></td>          <td></td>               <td></td></tr>
  * <tr><td><code>*</code></td>                 <td></td>               <td>user properties</td></tr>
  * <tr><td><code>*</code></td>                 <td></td>               <td>system properties</td></tr>
  * <tr><td><code>*</code></td>                 <td></td>               <td>project properties</td></tr>
  * </table>
- * <i>Notice:</i> <code>reports</code> was supported in Maven 2.x but was removed in Maven 3
  *
  * @see Session
+ * @see Project
+ * @see org.apache.maven.api.settings.Settings
  * @see MojoExecution
  */
 public class PluginParameterExpressionEvaluatorV4 implements TypeAwareExpressionEvaluator {
@@ -165,19 +146,18 @@ public class PluginParameterExpressionEvaluatorV4 implements TypeAwareExpression
             return expression.replace("$$", "$");
         }
 
-        if ("localRepository".equals(expression)) {
+        Map<String, Object> objects = new HashMap<>();
-            // TODO: v4
+        objects.put("session.", session);
-            value = session.getLocalRepository();
+        objects.put("project.", project);
-        } else if ("session".equals(expression)) {
+        objects.put("mojo.", mojoExecution);
-            value = session;
+        objects.put("settings.", session.getSettings());
-        } else if (expression.startsWith("session")) {
+        for (Map.Entry<String, Object> ctx : objects.entrySet()) {
-            // TODO: v4
+            if (expression.startsWith(ctx.getKey())) {
                 try {
                     int pathSeparator = expression.indexOf('/');
-
                     if (pathSeparator > 0) {
                         String pathExpression = expression.substring(0, pathSeparator);
-                    value = ReflectionValueExtractor.evaluate(pathExpression, session);
+                        value = ReflectionValueExtractor.evaluate(pathExpression, ctx.getValue());
                         if (pathSeparator < expression.length() - 1) {
                             if (value instanceof Path) {
                                 value = ((Path) value).resolve(expression.substring(pathSeparator + 1));
@@ -186,108 +166,14 @@ public class PluginParameterExpressionEvaluatorV4 implements TypeAwareExpression
                             }
                         }
                     } else {
-                    value = ReflectionValueExtractor.evaluate(expression, session);
+                        value = ReflectionValueExtractor.evaluate(expression, ctx.getValue());
                     }
+                    break;
                 } catch (Exception e) {
                     // TODO don't catch exception
                     throw new ExpressionEvaluationException(
                             "Error evaluating plugin parameter expression: " + expression, e);
                 }
-        } else if ("reactorProjects".equals(expression)) {
-            value = session.getProjects();
-        } else if ("project".equals(expression)) {
-            value = project;
-        } else if ("executedProject".equals(expression)) {
-            value = ((DefaultSession) session)
-                    .getProject(((DefaultSession) session)
-                            .getMavenSession()
-                            .getCurrentProject()
-                            .getExecutionProject());
-        } else if (expression.startsWith("project") || expression.startsWith("pom")) {
-            // TODO: v4
-            try {
-                int pathSeparator = expression.indexOf('/');
-
-                if (pathSeparator > 0) {
-                    String pathExpression = expression.substring(0, pathSeparator);
-                    value = ReflectionValueExtractor.evaluate(pathExpression, project);
-                    value = value + expression.substring(pathSeparator);
-                } else {
-                    value = ReflectionValueExtractor.evaluate(expression, project);
-                }
-            } catch (Exception e) {
-                // TODO don't catch exception
-                throw new ExpressionEvaluationException(
-                        "Error evaluating plugin parameter expression: " + expression, e);
-            }
-        } else if (expression.equals("repositorySystemSession")) {
-            // TODO: v4
-        } else if (expression.equals("mojo") || expression.equals("mojoExecution")) {
-            value = new DefaultMojoExecution(mojoExecution);
-        } else if (expression.startsWith("mojo")) {
-            // TODO: v4
-            try {
-                int pathSeparator = expression.indexOf('/');
-
-                if (pathSeparator > 0) {
-                    String pathExpression = expression.substring(0, pathSeparator);
-                    value = ReflectionValueExtractor.evaluate(pathExpression, mojoExecution);
-                    value = value + expression.substring(pathSeparator);
-                } else {
-                    value = ReflectionValueExtractor.evaluate(expression, mojoExecution);
-                }
-            } catch (Exception e) {
-                // TODO don't catch exception
-                throw new ExpressionEvaluationException(
-                        "Error evaluating plugin parameter expression: " + expression, e);
-            }
-        } else if (expression.equals("plugin")) {
-            // TODO: v4
-            value = mojoExecution.getMojoDescriptor().getPluginDescriptor();
-        } else if (expression.startsWith("plugin")) {
-            // TODO: v4
-            try {
-                int pathSeparator = expression.indexOf('/');
-
-                PluginDescriptor pluginDescriptor =
-                        mojoExecution.getMojoDescriptor().getPluginDescriptor();
-
-                if (pathSeparator > 0) {
-                    String pathExpression = expression.substring(0, pathSeparator);
-                    value = ReflectionValueExtractor.evaluate(pathExpression, pluginDescriptor);
-                    value = value + expression.substring(pathSeparator);
-                } else {
-                    value = ReflectionValueExtractor.evaluate(expression, pluginDescriptor);
-                }
-            } catch (Exception e) {
-                throw new ExpressionEvaluationException(
-                        "Error evaluating plugin parameter expression: " + expression, e);
-            }
-        } else if ("settings".equals(expression)) {
-            value = session.getSettings();
-        } else if (expression.startsWith("settings")) {
-            try {
-                int pathSeparator = expression.indexOf('/');
-
-                if (pathSeparator > 0) {
-                    String pathExpression = expression.substring(0, pathSeparator);
-                    value = ReflectionValueExtractor.evaluate(pathExpression, session.getSettings());
-                    value = value + expression.substring(pathSeparator);
-                } else {
-                    value = ReflectionValueExtractor.evaluate(expression, session.getSettings());
-                }
-            } catch (Exception e) {
-                // TODO don't catch exception
-                throw new ExpressionEvaluationException(
-                        "Error evaluating plugin parameter expression: " + expression, e);
-            }
-        } else if ("basedir".equals(expression)) {
-            value = basedir.toString();
-        } else if (expression.startsWith("basedir")) {
-            int pathSeparator = expression.indexOf('/');
-
-            if (pathSeparator > 0) {
-                value = basedir.toString() + expression.substring(pathSeparator);
             }
         }
 

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

@@ -25,7 +25,6 @@ import javax.inject.Singleton;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.PrintStream;
 import java.nio.file.Files;
 import java.util.ArrayList;
@@ -39,13 +38,16 @@ import java.util.jar.JarFile;
 import java.util.stream.Collectors;
 import java.util.zip.ZipEntry;
 
+import com.google.inject.AbstractModule;
+import com.google.inject.name.Names;
 import org.apache.maven.RepositoryUtils;
 import org.apache.maven.api.xml.XmlNode;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.classrealm.ClassRealmManager;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.execution.scope.internal.MojoExecutionScopeModule;
-import org.apache.maven.internal.impl.DefaultSession;
+import org.apache.maven.internal.impl.DefaultMojoExecution;
+import org.apache.maven.internal.impl.InternalSession;
 import org.apache.maven.internal.xml.XmlPlexusConfiguration;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.ContextEnabled;
@@ -220,18 +222,18 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
                     ZipEntry pluginDescriptorEntry = pluginJar.getEntry(getPluginDescriptorLocation());
 
                     if (pluginDescriptorEntry != null) {
-                        InputStream is = pluginJar.getInputStream(pluginDescriptorEntry);
+                        pluginDescriptor = parsePluginDescriptor(
-
+                                () -> pluginJar.getInputStream(pluginDescriptorEntry),
-                        pluginDescriptor = parsePluginDescriptor(is, plugin, pluginFile.getAbsolutePath());
+                                plugin,
+                                pluginFile.getAbsolutePath());
                     }
                 }
             } else {
                 File pluginXml = new File(pluginFile, getPluginDescriptorLocation());
 
                 if (pluginXml.isFile()) {
-                    try (InputStream is = Files.newInputStream(pluginXml.toPath())) {
+                    pluginDescriptor = parsePluginDescriptor(
-                        pluginDescriptor = parsePluginDescriptor(is, plugin, pluginXml.getAbsolutePath());
+                            () -> Files.newInputStream(pluginXml.toPath()), plugin, pluginXml.getAbsolutePath());
-                    }
                 }
             }
 
@@ -259,7 +261,8 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
         return "META-INF/maven/plugin.xml";
     }
 
-    private PluginDescriptor parsePluginDescriptor(InputStream is, Plugin plugin, String descriptorLocation)
+    private PluginDescriptor parsePluginDescriptor(
+            PluginDescriptorBuilder.StreamSupplier is, Plugin plugin, String descriptorLocation)
             throws PluginDescriptorParsingException {
         try {
             return builder.build(is, descriptorLocation);
@@ -410,6 +413,7 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
 
         discoverPluginComponents(pluginRealm, plugin, pluginDescriptor);
 
+        pluginDescriptor.setDependencyNode(root);
         pluginDescriptor.setClassRealm(pluginRealm);
         pluginDescriptor.setArtifacts(pluginArtifacts);
     }
@@ -419,15 +423,40 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
             throws PluginContainerException {
         try {
             if (pluginDescriptor != null) {
-                for (ComponentDescriptor<?> componentDescriptor : pluginDescriptor.getComponents()) {
+                for (MojoDescriptor mojo : pluginDescriptor.getMojos()) {
-                    componentDescriptor.setRealm(pluginRealm);
+                    if (!mojo.isV4Api()) {
-                    container.addComponentDescriptor(componentDescriptor);
+                        mojo.setRealm(pluginRealm);
+                        container.addComponentDescriptor(mojo);
+                    }
                 }
             }
 
             ((DefaultPlexusContainer) container)
                     .discoverComponents(
                             pluginRealm,
+                            new AbstractModule() {
+                                @Override
+                                protected void configure() {
+                                    if (pluginDescriptor != null) {
+                                        for (MojoDescriptor mojo : pluginDescriptor.getMojos()) {
+                                            if (mojo.isV4Api()) {
+                                                try {
+                                                    mojo.setRealm(pluginRealm);
+                                                    Class<?> cl = mojo.getImplementationClass();
+                                                    if (cl == null) {
+                                                        cl = pluginRealm.loadClass(mojo.getImplementation());
+                                                    }
+                                                    bind(org.apache.maven.api.plugin.Mojo.class)
+                                                            .annotatedWith(Names.named(mojo.getId()))
+                                                            .to((Class) cl);
+                                                } catch (ClassNotFoundException e) {
+                                                    throw new IllegalStateException("Unable to load mojo class", e);
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            },
                             new SessionScopeModule(container),
                             new MojoExecutionScopeModule(container),
                             new PluginConfigurationModule(plugin.getDelegate()));
@@ -584,11 +613,12 @@ public class DefaultMavenPluginManager implements MavenPluginManager {
             }
 
             ExpressionEvaluator expressionEvaluator;
+            InternalSession sessionV4 = InternalSession.from(session.getSession());
             if (mojoDescriptor.isV4Api()) {
                 expressionEvaluator = new PluginParameterExpressionEvaluatorV4(
-                        session.getSession(),
+                        sessionV4,
-                        ((DefaultSession) session.getSession()).getProject(session.getCurrentProject()),
+                        sessionV4.getProject(session.getCurrentProject()),
-                        mojoExecution);
+                        new DefaultMojoExecution(sessionV4, mojoExecution));
             } else {
                 expressionEvaluator = new PluginParameterExpressionEvaluator(session, mojoExecution);
             }

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

@@ -39,7 +39,7 @@ 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.DefaultSession;
+import org.apache.maven.internal.impl.InternalSession;
 import org.apache.maven.model.Build;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.model.DependencyManagement;
@@ -860,7 +860,7 @@ public class DefaultProjectBuilder implements ProjectBuilder {
                 modelBuildingRequest.setModelCache(modelCacheFactory.createCache(session));
             }
             modelBuildingRequest.setTransformerContextBuilder(transformerContextBuilder);
-            DefaultSession session = (DefaultSession) this.session.getData().get(DefaultSession.class);
+            InternalSession session = (InternalSession) this.session.getData().get(InternalSession.class);
             if (session != null) {
                 try {
                     modelBuildingRequest.setRootDirectory(session.getRootDirectory());

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

@@ -110,10 +110,19 @@ public class SessionScope implements Scope {
             return method.invoke(getScopeState().scope(key, unscoped).get(), args);
         };
         Class<T> superType = (Class<T>) key.getTypeLiteral().getRawType();
+        Class<?>[] interfaces = getInterfaces(superType);
+        return (T) java.lang.reflect.Proxy.newProxyInstance(superType.getClassLoader(), interfaces, dispatcher);
+    }
+
+    private Class<?>[] getInterfaces(Class<?> superType) {
+        if (superType.isInterface()) {
+            return new Class<?>[] {superType};
+        } else {
             for (Annotation a : superType.getAnnotations()) {
                 Class<? extends Annotation> annotationType = a.annotationType();
                 if ("org.eclipse.sisu.Typed".equals(annotationType.getName())
-                    || "javax.enterprise.inject.Typed".equals(annotationType.getName())) {
+                        || "javax.enterprise.inject.Typed".equals(annotationType.getName())
+                        || "jakarta.enterprise.inject.Typed".equals(annotationType.getName())) {
                     try {
                         Class<?>[] value =
                                 (Class<?>[]) annotationType.getMethod("value").invoke(a);
@@ -127,7 +136,7 @@ public class SessionScope implements Scope {
                                     "The Typed annotation must contain only interfaces but the following types are not: "
                                             + nonInterfaces);
                         }
-                    return (T) java.lang.reflect.Proxy.newProxyInstance(superType.getClassLoader(), value, dispatcher);
+                        return value;
                     } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
                         throw new IllegalStateException(e);
                     }
@@ -136,6 +145,7 @@ public class SessionScope implements Scope {
             throw new IllegalArgumentException("The use of session scoped proxies require "
                     + "a org.eclipse.sisu.Typed or javax.enterprise.inject.Typed annotation");
         }
+    }
 
     /**
      * A provider wrapping an existing provider with a cache
@@ -170,4 +180,10 @@ public class SessionScope implements Scope {
     public static <T> Provider<T> seededKeyProvider() {
         return (Provider<T>) SEEDED_KEY_PROVIDER;
     }
+
+    public static <T> Provider<T> seededKeyProvider(Class<? extends T> clazz) {
+        return () -> {
+            throw new IllegalStateException("No instance of " + clazz.getName() + " is bound to the session scope.");
+        };
+    }
 }

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.DefaultSession;
+import org.apache.maven.internal.impl.InternalSession;
 import org.codehaus.plexus.PlexusContainer;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
 
@@ -52,10 +52,17 @@ public class SessionScopeModule extends AbstractModule {
     @Override
     protected void configure() {
         bindScope(SessionScoped.class, scope);
+        bindScope(org.apache.maven.api.di.SessionScoped.class, scope);
         bind(SessionScope.class).toInstance(scope);
 
-        bind(MavenSession.class).toProvider(SessionScope.seededKeyProvider()).in(scope);
+        bind(MavenSession.class)
-        bind(Session.class).toProvider(SessionScope.seededKeyProvider()).in(scope);
+                .toProvider(SessionScope.seededKeyProvider(MavenSession.class))
-        bind(DefaultSession.class).toProvider(SessionScope.seededKeyProvider()).in(scope);
+                .in(scope);
+        bind(Session.class)
+                .toProvider(SessionScope.seededKeyProvider(Session.class))
+                .in(scope);
+        bind(InternalSession.class)
+                .toProvider(SessionScope.seededKeyProvider(InternalSession.class))
+                .in(scope);
     }
 }

maven-core/src/main/resources/META-INF/maven/extension.xml

@@ -111,6 +111,9 @@ under the License.
     <exportedPackage>javax.annotation.*</exportedPackage>
     <exportedPackage>javax.annotation.security.*</exportedPackage>
 
+    <exportedPackage>jakarta.inject.*</exportedPackage>
+    <exportedPackage>jakarta.annotation.*</exportedPackage>
+
     <!--
       | We may potentially want to export these, but right now I'm not sure that anything Guice specific needs
       | to be made available to plugin authors. If we find people are getting fancy and want to take advantage of

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

@@ -98,7 +98,7 @@ class TestApi {
         RepositorySystemSession rss = MavenRepositorySystemUtils.newSession();
         DefaultMavenExecutionRequest mer = new DefaultMavenExecutionRequest();
         DefaultMavenExecutionResult meres = new DefaultMavenExecutionResult();
-        MavenSession ms = new MavenSession(() -> rss, mer, meres);
+        MavenSession ms = new MavenSession(rss, mer, meres);
         DefaultSession session = new DefaultSession(
                 ms,
                 repositorySystem,
@@ -114,7 +114,7 @@ class TestApi {
                 .withRemoteRepositories(Collections.singletonList(remoteRepository));
 
         sessionScope.enter();
-        sessionScope.seed(DefaultSession.class, (DefaultSession) this.session);
+        sessionScope.seed(InternalSession.class, InternalSession.from(this.session));
     }
 
     @Test

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

@@ -401,7 +401,7 @@ class PluginParameterExpressionEvaluatorTest extends AbstractCoreMavenComponentT
         mavenSession.getRequest().setTopDirectory(path);
         mavenSession.getRequest().setRootDirectory(path);
 
-        Object result = new PluginParameterExpressionEvaluatorV4(mavenSession.getSession(), null)
+        Object result = new PluginParameterExpressionEvaluator(mavenSession, new MojoExecution(null))
                 .evaluate("${session.rootDirectory.uri}");
         assertEquals(path.toUri(), result);
     }
@@ -414,7 +414,7 @@ class PluginParameterExpressionEvaluatorTest extends AbstractCoreMavenComponentT
         mavenSession.getRequest().setTopDirectory(path);
         mavenSession.getRequest().setRootDirectory(path);
 
-        Object result = new PluginParameterExpressionEvaluatorV4(mavenSession.getSession(), null)
+        Object result = new PluginParameterExpressionEvaluator(mavenSession, new MojoExecution(null))
                 .evaluate("${session.rootDirectory/target}");
         assertEquals(path.resolve("target"), result);
     }
@@ -428,8 +428,8 @@ class PluginParameterExpressionEvaluatorTest extends AbstractCoreMavenComponentT
         mavenSession.getRequest().setRootDirectory(path);
         DefaultModelBuildingRequest mbr = new DefaultModelBuildingRequest();
 
-        PluginParameterExpressionEvaluatorV4 evaluator =
+        PluginParameterExpressionEvaluator evaluator =
-                new PluginParameterExpressionEvaluatorV4(mavenSession.getSession(), null);
+                new PluginParameterExpressionEvaluator(mavenSession, new MojoExecution(null));
 
         DefaultPlexusConfiguration configuration = new DefaultPlexusConfiguration("config");
         configuration.addChild("uri", "${session.rootDirectory.uri}");
@@ -438,7 +438,7 @@ class PluginParameterExpressionEvaluatorTest extends AbstractCoreMavenComponentT
         configuration.addChild("uriAsciiString", "${session.rootDirectory.uri.ASCIIString}");
         configuration.addChild("pathString", "${session.rootDirectory.string}");
 
-        PluginParameterExpressionEvaluatorV4Test.Mojo mojo = new PluginParameterExpressionEvaluatorV4Test.Mojo();
+        Mojo mojo = new Mojo();
         new EnhancedComponentConfigurator().configureComponent(mojo, configuration, evaluator, null);
 
         assertEquals(

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

@@ -24,17 +24,19 @@ import java.io.File;
 import java.net.URI;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
-import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Properties;
 
 import org.apache.maven.AbstractCoreMavenComponentTestCase;
+import org.apache.maven.RepositoryUtils;
+import org.apache.maven.api.Artifact;
+import org.apache.maven.api.MojoExecution;
 import org.apache.maven.api.Session;
-import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.DefaultArtifact;
-import org.apache.maven.artifact.ArtifactUtils;
+import org.apache.maven.artifact.handler.DefaultArtifactHandler;
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.bridge.MavenRepositorySystem;
 import org.apache.maven.configuration.internal.EnhancedComponentConfigurator;
@@ -42,10 +44,11 @@ import org.apache.maven.execution.DefaultMavenExecutionRequest;
 import org.apache.maven.execution.DefaultMavenExecutionResult;
 import org.apache.maven.execution.MavenExecutionRequest;
 import org.apache.maven.execution.MavenSession;
+import org.apache.maven.internal.impl.AbstractSession;
+import org.apache.maven.internal.impl.DefaultMojoExecution;
 import org.apache.maven.internal.impl.DefaultProject;
 import org.apache.maven.internal.impl.DefaultSession;
 import org.apache.maven.model.Build;
-import org.apache.maven.model.Dependency;
 import org.apache.maven.model.Model;
 import org.apache.maven.model.building.DefaultModelBuildingRequest;
 import org.apache.maven.model.interpolation.reflection.IntrospectionException;
@@ -62,6 +65,7 @@ import org.codehaus.plexus.configuration.DefaultPlexusConfiguration;
 import org.codehaus.plexus.util.Os;
 import org.eclipse.aether.DefaultRepositorySystemSession;
 import org.eclipse.aether.RepositorySystem;
+import org.eclipse.aether.graph.DefaultDependencyNode;
 import org.eclipse.aether.internal.impl.SimpleLocalRepositoryManagerFactory;
 import org.eclipse.aether.repository.LocalRepository;
 import org.eclipse.aether.repository.NoLocalRepositoryManagerException;
@@ -82,6 +86,9 @@ import static org.mockito.Mockito.mock;
 public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenComponentTestCase {
     private static final String FS = File.separator;
 
+    @Inject
+    PlexusContainer container;
+
     @Inject
     private MavenRepositorySystem factory;
 
@@ -89,83 +96,74 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
     @Test
     public void testPluginDescriptorExpressionReference() throws Exception {
-        MojoExecution exec = newMojoExecution();
-
         Session session = newSession();
+        MojoExecution exec = newMojoExecution(session);
 
-        Object result = new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${plugin}");
+        Object result =
+                new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${mojo.plugin.descriptor}");
 
         System.out.println("Result: " + result);
 
         assertSame(
-                exec.getMojoDescriptor().getPluginDescriptor(),
+                exec.getPlugin().getDescriptor(),
                 result,
-                "${plugin} expression does not return plugin descriptor.");
+                "${mojo.plugin.descriptor} expression does not return plugin descriptor.");
     }
 
     @Test
     public void testPluginArtifactsExpressionReference() throws Exception {
-        MojoExecution exec = newMojoExecution();
-
-        Artifact depArtifact = createArtifact("group", "artifact", "1");
-
-        List<Artifact> deps = new ArrayList<>();
-        deps.add(depArtifact);
-
-        exec.getMojoDescriptor().getPluginDescriptor().setArtifacts(deps);
-
         Session session = newSession();
+        MojoExecution exec = newMojoExecution(session);
 
         @SuppressWarnings("unchecked")
-        List<Artifact> depResults = (List<Artifact>)
+        Collection<Artifact> depResults = (Collection<Artifact>)
-                new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${plugin.artifacts}");
+                new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${mojo.plugin.dependencies}");
 
         System.out.println("Result: " + depResults);
 
         assertNotNull(depResults);
         assertEquals(1, depResults.size());
-        assertSame(depArtifact, depResults.get(0), "dependency artifact is wrong.");
+        assertEquals(
+                exec.getPlugin().getArtifact().key(),
+                depResults.iterator().next().key(),
+                "dependency artifact is wrong.");
     }
 
     @Test
     public void testPluginArtifactMapExpressionReference() throws Exception {
-        MojoExecution exec = newMojoExecution();
-
-        Artifact depArtifact = createArtifact("group", "artifact", "1");
-
-        List<Artifact> deps = new ArrayList<>();
-        deps.add(depArtifact);
-
-        exec.getMojoDescriptor().getPluginDescriptor().setArtifacts(deps);
-
         Session session = newSession();
 
+        MojoExecution exec = newMojoExecution(session);
+
         @SuppressWarnings("unchecked")
-        Map<String, Artifact> depResults = (Map<String, Artifact>)
+        Map<String, org.apache.maven.api.Dependency> depResults = (Map<String, org.apache.maven.api.Dependency>)
-                new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${plugin.artifactMap}");
+                new PluginParameterExpressionEvaluatorV4(session, null, exec)
+                        .evaluate("${mojo.plugin.dependenciesMap}");
 
         System.out.println("Result: " + depResults);
 
         assertNotNull(depResults);
         assertEquals(1, depResults.size());
-        assertSame(
+        assertTrue(depResults.containsKey("org.myco.plugins:my-plugin"));
-                depArtifact,
+        assertEquals(
-                depResults.get(ArtifactUtils.versionlessKey(depArtifact)),
+                exec.getPlugin().getArtifact().key(),
+                depResults.get("org.myco.plugins:my-plugin").key(),
                 "dependency artifact is wrong.");
     }
 
     @Test
     public void testPluginArtifactIdExpressionReference() throws Exception {
-        MojoExecution exec = newMojoExecution();
-
         Session session = newSession();
 
-        Object result = new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${plugin.artifactId}");
+        MojoExecution exec = newMojoExecution(session);
+
+        Object result = new PluginParameterExpressionEvaluatorV4(session, null, exec)
+                .evaluate("${mojo.plugin.artifact.artifactId}");
 
         System.out.println("Result: " + result);
 
         assertSame(
-                exec.getMojoDescriptor().getPluginDescriptor().getArtifactId(),
+                exec.getPlugin().getArtifact().getArtifactId(),
                 result,
                 "${plugin.artifactId} expression does not return plugin descriptor's artifactId.");
     }
@@ -183,7 +181,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
         MavenProject project = new MavenProject(model);
         project.setFile(new File("pom.xml").getCanonicalFile());
 
-        ExpressionEvaluator expressionEvaluator = createExpressionEvaluator(project, null, new Properties());
+        ExpressionEvaluator expressionEvaluator = createExpressionEvaluator(project, new Properties());
 
         Object value = expressionEvaluator.evaluate("${project.build.directory}/classes");
         String actual = new File(value.toString()).getCanonicalPath();
@@ -200,7 +198,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
         MavenProject project = new MavenProject(model);
 
-        ExpressionEvaluator ee = createExpressionEvaluator(project, null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(project, new Properties());
 
         Object value = ee.evaluate("$" + var);
 
@@ -217,7 +215,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
         MavenProject project = new MavenProject(model);
 
-        ExpressionEvaluator ee = createExpressionEvaluator(project, null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(project, new Properties());
 
         Object value = ee.evaluate("$" + key);
 
@@ -234,7 +232,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
         MavenProject project = new MavenProject(model);
 
-        ExpressionEvaluator ee = createExpressionEvaluator(project, null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(project, new Properties());
 
         Object value = ee.evaluate(key);
 
@@ -247,7 +245,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
         MavenProject project = new MavenProject(new Model());
 
-        ExpressionEvaluator ee = createExpressionEvaluator(project, null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(project, new Properties());
 
         Object value = ee.evaluate(expr);
 
@@ -267,22 +265,13 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
         MavenProject project = new MavenProject(model);
 
-        ExpressionEvaluator ee = createExpressionEvaluator(project, null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(project, new Properties());
 
         Object value = ee.evaluate("${" + key + "}");
 
         assertEquals(checkValue, value);
     }
 
-    @Test
-    public void testBasedirExtractionWithMissingProject() throws Exception {
-        ExpressionEvaluator ee = createExpressionEvaluator(null, null, new Properties());
-
-        Object value = ee.evaluate("${basedir}");
-
-        assertEquals(System.getProperty("user.dir"), value);
-    }
-
     @Test
     public void testValueExtractionFromSystemPropertiesWithMissingProject() throws Exception {
         String sysprop = "PPEET_sysprop1";
@@ -293,7 +282,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
             executionProperties.setProperty(sysprop, "value");
         }
 
-        ExpressionEvaluator ee = createExpressionEvaluator(null, null, executionProperties);
+        ExpressionEvaluator ee = createExpressionEvaluator(null, executionProperties);
 
         Object value = ee.evaluate("${" + sysprop + "}");
 
@@ -310,7 +299,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
             executionProperties.setProperty(sysprop, "value");
         }
 
-        ExpressionEvaluator ee = createExpressionEvaluator(null, null, executionProperties);
+        ExpressionEvaluator ee = createExpressionEvaluator(null, executionProperties);
 
         Object value = ee.evaluate("${" + sysprop + "}");
 
@@ -335,15 +324,6 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
         return session;
     }
 
-    @Test
-    public void testLocalRepositoryExtraction() throws Exception {
-        ExpressionEvaluator expressionEvaluator =
-                createExpressionEvaluator(createDefaultProject(), null, new Properties());
-        Object value = expressionEvaluator.evaluate("${localRepository}");
-
-        assertEquals("local", ((org.apache.maven.api.LocalRepository) value).getId());
-    }
-
     @Test
     public void testTwoExpressions() throws Exception {
         Build build = new Build();
@@ -353,8 +333,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
         Model model = new Model();
         model.setBuild(build);
 
-        ExpressionEvaluator expressionEvaluator =
+        ExpressionEvaluator expressionEvaluator = createExpressionEvaluator(new MavenProject(model), new Properties());
-                createExpressionEvaluator(new MavenProject(model), null, new Properties());
 
         Object value = expressionEvaluator.evaluate("${project.build.directory}" + FS + "${project.build.finalName}");
 
@@ -363,37 +342,31 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
 
     @Test
     public void testShouldExtractPluginArtifacts() throws Exception {
-        PluginDescriptor pd = new PluginDescriptor();
+        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), new Properties());
 
-        Artifact artifact = createArtifact("testGroup", "testArtifact", "1.0");
+        Object value = ee.evaluate("${mojo.plugin.dependencies}");
 
-        pd.setArtifacts(Collections.singletonList(artifact));
+        assertTrue(value instanceof Collection);
-
-        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), pd, new Properties());
-
-        Object value = ee.evaluate("${plugin.artifacts}");
-
-        assertTrue(value instanceof List);
 
         @SuppressWarnings("unchecked")
-        List<Artifact> artifacts = (List<Artifact>) value;
+        Collection<Artifact> artifacts = (Collection<Artifact>) value;
 
         assertEquals(1, artifacts.size());
 
-        Artifact result = artifacts.get(0);
+        Artifact result = artifacts.iterator().next();
 
-        assertEquals("testGroup", result.getGroupId());
+        assertEquals("org.myco.plugins", result.getGroupId());
     }
 
     @Test
     void testRootDirectoryNotPrefixed() throws Exception {
-        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), new Properties());
         assertNull(ee.evaluate("${rootDirectory}"));
     }
 
     @Test
     void testRootDirectoryWithNull() throws Exception {
-        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), new Properties());
         Exception e = assertThrows(Exception.class, () -> ee.evaluate("${session.rootDirectory}"));
         e = assertInstanceOf(IntrospectionException.class, e.getCause());
         e = assertInstanceOf(IllegalStateException.class, e.getCause());
@@ -403,7 +376,7 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
     @Test
     void testRootDirectory() throws Exception {
         this.rootDirectory = Paths.get("myRootDirectory");
-        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), null, new Properties());
+        ExpressionEvaluator ee = createExpressionEvaluator(createDefaultProject(), new Properties());
         assertInstanceOf(Path.class, ee.evaluate("${session.rootDirectory}"));
     }
 
@@ -411,54 +384,59 @@ public class PluginParameterExpressionEvaluatorV4Test extends AbstractCoreMavenC
         return new MavenProject(new Model());
     }
 
-    private ExpressionEvaluator createExpressionEvaluator(
+    private ExpressionEvaluator createExpressionEvaluator(MavenProject project, Properties executionProperties)
-            MavenProject project, PluginDescriptor pluginDescriptor, Properties executionProperties) throws Exception {
+            throws Exception {
         ArtifactRepository repo = getLocalRepository();
 
         MutablePlexusContainer container = (MutablePlexusContainer) getContainer();
         MavenSession mavenSession = createSession(container, repo, executionProperties);
         mavenSession.setCurrentProject(project);
         mavenSession.getRequest().setRootDirectory(rootDirectory);
+        mavenSession.getRequest().setTopDirectory(rootDirectory);
 
-        DefaultSession session = new DefaultSession(mavenSession, mock(RepositorySystem.class), null, null, null, null);
+        DefaultSession session =
+                new DefaultSession(mavenSession, mock(RepositorySystem.class), null, null, container, null);
 
-        MojoDescriptor mojo = new MojoDescriptor();
+        MojoExecution mojoExecution = newMojoExecution(session);
-        mojo.setPluginDescriptor(pluginDescriptor);
-        mojo.setGoal("goal");
-
-        MojoExecution mojoExecution = new MojoExecution(mojo);
 
         return new PluginParameterExpressionEvaluatorV4(
                 session, project != null ? new DefaultProject(session, project) : null, mojoExecution);
     }
 
-    protected Artifact createArtifact(String groupId, String artifactId, String version) throws Exception {
+    private MojoExecution newMojoExecution(Session session) {
-        Dependency dependency = new Dependency();
-        dependency.setGroupId(groupId);
-        dependency.setArtifactId(artifactId);
-        dependency.setVersion(version);
-        dependency.setType("jar");
-        dependency.setScope("compile");
-
-        return factory.createDependencyArtifact(dependency);
-    }
-
-    private MojoExecution newMojoExecution() {
         PluginDescriptor pd = new PluginDescriptor();
         pd.setArtifactId("my-plugin");
         pd.setGroupId("org.myco.plugins");
         pd.setVersion("1");
 
+        DefaultArtifact artifact = new DefaultArtifact(
+                pd.getGroupId(),
+                pd.getArtifactId(),
+                pd.getVersion(),
+                "compile",
+                "maven-plugin",
+                "",
+                new DefaultArtifactHandler("maven-plugin"));
+        pd.setPluginArtifact(artifact);
+
+        pd.setArtifacts(Collections.singletonList(artifact));
+        DefaultDependencyNode node = new DefaultDependencyNode(
+                new org.eclipse.aether.graph.Dependency(RepositoryUtils.toArtifact(artifact), "compile"));
+        pd.setDependencyNode(node);
+
         MojoDescriptor md = new MojoDescriptor();
+        md.setGoal("my-goal");
         md.setPluginDescriptor(pd);
 
         pd.addComponentDescriptor(md);
 
-        return new MojoExecution(md);
+        return new DefaultMojoExecution((AbstractSession) session, new org.apache.maven.plugin.MojoExecution(md));
     }
 
     private DefaultSession newSession() throws Exception {
-        return new DefaultSession(newMavenSession(), mock(RepositorySystem.class), null, null, null, null);
+        DefaultSession session =
+                new DefaultSession(newMavenSession(), mock(RepositorySystem.class), null, null, container, null);
+        return session;
     }
 
     private MavenSession newMavenSession() throws Exception {

maven-core/src/test/java/org/apache/maven/session/scope/SessionScopeProxyTest.java

@@ -23,8 +23,8 @@ import javax.inject.Named;
 import javax.inject.Singleton;
 
 import com.google.inject.OutOfScopeException;
-import org.apache.maven.SessionScoped;
 import org.apache.maven.api.Session;
+import org.apache.maven.api.di.SessionScoped;
 import org.apache.maven.session.scope.internal.SessionScope;
 import org.codehaus.plexus.PlexusContainer;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;

maven-model-builder/src/main/java/org/apache/maven/model/interpolation/reflection/ReflectionValueExtractor.java

@@ -26,6 +26,7 @@ import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.WeakHashMap;
 
 import org.apache.maven.api.annotations.Nonnull;
@@ -213,6 +214,9 @@ public class ReflectionValueExtractor {
             }
         }
 
+        if (value instanceof Optional) {
+            value = ((Optional<?>) value).orElse(null);
+        }
         return value;
     }
 

maven-plugin-api/pom.xml

@@ -32,6 +32,10 @@ under the License.
   <description>The API for plugins - Mojos - development.</description>
 
   <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-api-plugin</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-model</artifactId>
@@ -54,6 +58,10 @@ under the License.
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-classworlds</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.apache.maven.resolver</groupId>
+      <artifactId>maven-resolver-api</artifactId>
+    </dependency>
   </dependencies>
 
   <build>
@@ -63,44 +71,55 @@ under the License.
         <artifactId>modello-maven-plugin</artifactId>
         <configuration>
           <velocityBasedir>${project.basedir}/../src/mdo</velocityBasedir>
-          <models>
-            <model>src/main/mdo/lifecycle.mdo</model>
-          </models>
-          <version>1.0.0</version>
         </configuration>
         <executions>
           <execution>
-            <id>velocity</id>
+            <id>velocity-lifecycle</id>
             <goals>
               <goal>velocity</goal>
             </goals>
             <phase>generate-sources</phase>
             <configuration>
               <templates>
-                <template>model.vm</template>
                 <template>reader-stax.vm</template>
                 <template>writer-stax.vm</template>
               </templates>
               <params>
-                <param>packageModelV3=org.apache.maven.plugin.lifecycle</param>
+                <param>packageModelV4=org.apache.maven.api.plugin.descriptor.lifecycle</param>
-                <param>packageModelV4=org.apache.maven.plugin.lifecycle</param>
                 <param>packageToolV4=org.apache.maven.plugin.lifecycle.io</param>
               </params>
+              <models>
+                <model>../api/maven-api-plugin/src/main/mdo/lifecycle.mdo</model>
+              </models>
+              <version>1.0.0</version>
             </configuration>
           </execution>
           <execution>
-            <id>modello-site-docs2</id>
+            <id>velocity-plugin</id>
             <goals>
-              <goal>xdoc</goal>
+              <goal>velocity</goal>
             </goals>
-            <phase>pre-site</phase>
+            <phase>generate-sources</phase>
             <configuration>
+              <templates>
+                <template>reader-stax.vm</template>
+                <template>writer-stax.vm</template>
+              </templates>
+              <params>
+                <param>packageModelV3=org.apache.maven.plugin.descriptor</param>
+                <param>packageModelV4=org.apache.maven.api.plugin.descriptor</param>
+                <param>packageToolV4=org.apache.maven.plugin.descriptor.io</param>
+              </params>
               <models>
-                <model>src/main/mdo/plugin.mdo</model>
+                <model>../api/maven-api-plugin/src/main/mdo/plugin.mdo</model>
               </models>
-              <version>1.1.0</version>
+              <version>2.0.0</version>
             </configuration>
           </execution>
+          <execution>
+            <id>modello-site-docs</id>
+            <phase>none</phase>
+          </execution>
         </executions>
       </plugin>
       <plugin>
@@ -110,32 +129,8 @@ under the License.
           <parameter>
             <excludes>
               <exclude>org.apache.maven.monitor.logging.DefaultLog</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Execution#addGoal(java.lang.String):METHOD_REMOVED</exclude>
+              <exclude>org.apache.maven.plugin.lifecycle</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Execution#getConfiguration():METHOD_RETURN_TYPE_CHANGED</exclude>
+              <exclude>org.apache.maven.plugin.descriptor.PluginDescriptor#getLifecycleMapping(java.lang.String)</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Execution#removeGoal(java.lang.String):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Execution#setConfiguration(java.lang.Object):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Execution#setGoals(java.util.List):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Execution#Execution():CONSTRUCTOR_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.io.xpp3.LifecycleMappingsXpp3Reader#contentTransformer</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Lifecycle#addPhase(org.apache.maven.plugin.lifecycle.Phase):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Lifecycle#removePhase(org.apache.maven.plugin.lifecycle.Phase):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Lifecycle#setId(java.lang.String):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Lifecycle#setPhases(java.util.List):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Lifecycle#Lifecycle():CONSTRUCTOR_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.LifecycleConfiguration#addLifecycle(org.apache.maven.plugin.lifecycle.Lifecycle):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.LifecycleConfiguration#removeLifecycle(org.apache.maven.plugin.lifecycle.Lifecycle):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.LifecycleConfiguration#setLifecycles(java.util.List):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.LifecycleConfiguration#setModelEncoding(java.lang.String):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.LifecycleConfiguration#LifecycleConfiguration():CONSTRUCTOR_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#addExecution(org.apache.maven.plugin.lifecycle.Execution):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#getConfiguration():METHOD_RETURN_TYPE_CHANGED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#removeExecution(org.apache.maven.plugin.lifecycle.Execution):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#setConfiguration(java.lang.Object):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#setExecutions(java.util.List):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#setId(java.lang.String):METHOD_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.Phase#Phase():CONSTRUCTOR_REMOVED</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.io.xpp3.LifecycleMappingsXpp3Reader</exclude>
-              <exclude>org.apache.maven.plugin.lifecycle.io.xpp3.LifecycleMappingsXpp3Writer</exclude>
             </excludes>
           </parameter>
         </configuration>

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

@@ -23,6 +23,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 import org.apache.maven.plugin.Mojo;
 import org.codehaus.plexus.component.repository.ComponentDescriptor;
@@ -146,6 +147,34 @@ public class MojoDescriptor extends ComponentDescriptor<Mojo> implements Cloneab
         setComponentFactory(DEFAULT_LANGUAGE);
     }
 
+    public MojoDescriptor(PluginDescriptor pd, org.apache.maven.api.plugin.descriptor.MojoDescriptor md) {
+        this();
+        this.setPluginDescriptor(pd);
+        this.setGoal(md.getGoal());
+        this.setExecuteGoal(md.getExecuteGoal());
+        this.setExecuteLifecycle(md.getExecuteLifecycle());
+        this.setExecutePhase(md.getExecutePhase());
+        this.setDeprecated(md.getDeprecated());
+        this.setLanguage(md.getLanguage());
+        this.setAggregator(md.isAggregator());
+        this.setDependencyCollectionRequired(md.getDependencyCollection());
+        this.setDependencyResolutionRequired(md.getDependencyResolution());
+        this.setComponentConfigurator(md.getConfigurator());
+        this.setInheritedByDefault(md.isInheritedByDefault());
+        this.setPhase(md.getPhase());
+        this.setOnlineRequired(md.isOnlineRequired());
+        this.setProjectRequired(md.isProjectRequired());
+        this.setSince(md.getSince());
+        this.setThreadSafe(true);
+        this.setV4Api(true);
+        this.setImplementation(md.getImplementation());
+        try {
+            this.setParameters(md.getParameters().stream().map(Parameter::new).collect(Collectors.toList()));
+        } catch (DuplicateParameterException e) {
+            throw new IllegalArgumentException(e);
+        }
+        this.mojoDescriptorV4 = md;
+    }
     // ----------------------------------------------------------------------
     //
     // ----------------------------------------------------------------------
@@ -608,4 +637,41 @@ public class MojoDescriptor extends ComponentDescriptor<Mojo> implements Cloneab
             throw new UnsupportedOperationException(e);
         }
     }
+
+    private volatile org.apache.maven.api.plugin.descriptor.MojoDescriptor mojoDescriptorV4;
+
+    public org.apache.maven.api.plugin.descriptor.MojoDescriptor getMojoDescriptorV4() {
+        if (mojoDescriptorV4 == null) {
+            synchronized (this) {
+                if (mojoDescriptorV4 == null) {
+                    mojoDescriptorV4 = org.apache.maven.api.plugin.descriptor.MojoDescriptor.newBuilder()
+                            .goal(goal)
+                            .description(getDescription())
+                            .implementation(getImplementation())
+                            .language(getLanguage())
+                            .phase(phase)
+                            .executeGoal(executeGoal)
+                            .executeLifecycle(executeLifecycle)
+                            .executePhase(executePhase)
+                            .aggregator(aggregator)
+                            .dependencyResolution(dependencyResolutionRequired)
+                            .dependencyCollection(dependencyCollectionRequired)
+                            .projectRequired(projectRequired)
+                            .onlineRequired(onlineRequired)
+                            .inheritedByDefault(inheritedByDefault)
+                            .since(since)
+                            .deprecated(deprecated)
+                            .configurator(getComponentConfigurator())
+                            .parameters(getParameters().stream()
+                                    .filter(p -> p.getRequirement() == null)
+                                    .map(Parameter::getParameterV4)
+                                    .collect(Collectors.toList()))
+                            .id(getId())
+                            .fullGoalName(getFullGoalName())
+                            .build();
+                }
+            }
+        }
+        return mojoDescriptorV4;
+    }
 }

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

@@ -49,6 +49,25 @@ public class Parameter implements Cloneable {
     //
     // ----------------------------------------------------------------------
 
+    public Parameter() {}
+
+    public Parameter(org.apache.maven.api.plugin.descriptor.Parameter p) {
+        this.setAlias(p.getAlias());
+        this.setName(p.getName());
+        this.setRequired(p.isRequired());
+        this.setEditable(p.isEditable());
+        this.setDescription(p.getDescription());
+        this.setExpression(p.getExpression());
+        this.setDeprecated(p.getDeprecated());
+        this.setDefaultValue(p.getDefaultValue());
+        this.setType(p.getType());
+        this.setSince(p.getSince());
+    }
+
+    // ----------------------------------------------------------------------
+    //
+    // ----------------------------------------------------------------------
+
     public String getName() {
         return name;
     }
@@ -168,4 +187,19 @@ public class Parameter implements Cloneable {
             throw new UnsupportedOperationException(e);
         }
     }
+
+    public org.apache.maven.api.plugin.descriptor.Parameter getParameterV4() {
+        return org.apache.maven.api.plugin.descriptor.Parameter.newBuilder()
+                .alias(alias)
+                .name(name)
+                .type(type)
+                .required(required)
+                .editable(editable)
+                .description(description)
+                .expression(expression)
+                .deprecated(deprecated)
+                .defaultValue(defaultValue)
+                .since(since)
+                .build();
+    }
 }

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

@@ -26,21 +26,25 @@ import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.nio.file.Files;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
+import org.apache.maven.api.plugin.descriptor.lifecycle.Lifecycle;
+import org.apache.maven.api.plugin.descriptor.lifecycle.LifecycleConfiguration;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.artifact.ArtifactUtils;
 import org.apache.maven.model.Plugin;
-import org.apache.maven.plugin.lifecycle.Lifecycle;
+import org.apache.maven.plugin.lifecycle.io.LifecycleStaxReader;
-import org.apache.maven.plugin.lifecycle.LifecycleConfiguration;
-import org.apache.maven.plugin.lifecycle.io.LifecycleMappingsStaxReader;
 import org.codehaus.plexus.classworlds.realm.ClassRealm;
+import org.codehaus.plexus.component.repository.ComponentDescriptor;
 import org.codehaus.plexus.component.repository.ComponentSetDescriptor;
+import org.eclipse.aether.graph.DependencyNode;
 
 /**
  */
@@ -64,6 +68,8 @@ public class PluginDescriptor extends ComponentSetDescriptor implements Cloneabl
 
     private List<Artifact> artifacts;
 
+    private DependencyNode dependencyNode;
+
     private ClassRealm classRealm;
 
     // calculated on-demand.
@@ -89,6 +95,67 @@ public class PluginDescriptor extends ComponentSetDescriptor implements Cloneabl
     //
     // ----------------------------------------------------------------------
 
+    public PluginDescriptor() {}
+
+    public PluginDescriptor(PluginDescriptor original) {
+        this.setGroupId(original.getGroupId());
+        this.setArtifactId(original.getArtifactId());
+        this.setVersion(original.getVersion());
+        this.setGoalPrefix(original.getGoalPrefix());
+        this.setInheritedByDefault(original.isInheritedByDefault());
+        this.setName(original.getName());
+        this.setDescription(original.getDescription());
+        this.setRequiredMavenVersion(original.getRequiredMavenVersion());
+        this.setRequiredJavaVersion(original.getRequiredJavaVersion());
+        this.setPluginArtifact(ArtifactUtils.copyArtifactSafe(original.getPluginArtifact()));
+        this.setComponents(clone(original.getMojos(), this));
+        this.setId(original.getId());
+        this.setIsolatedRealm(original.isIsolatedRealm());
+        this.setSource(original.getSource());
+        this.setDependencies(original.getDependencies());
+        this.setDependencyNode(original.getDependencyNode());
+    }
+
+    private static List<ComponentDescriptor<?>> clone(List<MojoDescriptor> mojos, PluginDescriptor pluginDescriptor) {
+        List<ComponentDescriptor<?>> clones = null;
+        if (mojos != null) {
+            clones = new ArrayList<>(mojos.size());
+            for (MojoDescriptor mojo : mojos) {
+                MojoDescriptor clone = mojo.clone();
+                clone.setPluginDescriptor(pluginDescriptor);
+                clones.add(clone);
+            }
+        }
+        return clones;
+    }
+
+    public PluginDescriptor(org.apache.maven.api.plugin.descriptor.PluginDescriptor original) {
+        this.setGroupId(original.getGroupId());
+        this.setArtifactId(original.getArtifactId());
+        this.setVersion(original.getVersion());
+        this.setGoalPrefix(original.getGoalPrefix());
+        this.setInheritedByDefault(original.isInheritedByDefault());
+        this.setName(original.getName());
+        this.setDescription(original.getDescription());
+        this.setRequiredMavenVersion(original.getRequiredMavenVersion());
+        this.setRequiredJavaVersion(original.getRequiredJavaVersion());
+        this.setPluginArtifact(null); // TODO: v4
+        this.setComponents(Collections.emptyList()); // TODO: v4
+        this.setComponents(original.getMojos().stream()
+                .map(m -> new MojoDescriptor(this, m))
+                .collect(Collectors.toList()));
+        this.setId(original.getId());
+        this.setIsolatedRealm(original.isIsolatedRealm());
+        this.setSource(null);
+        this.setDependencies(Collections.emptyList()); // TODO: v4
+        this.setDependencyNode(null); // TODO: v4
+        this.pluginDescriptorV4 = original;
+    }
+
+    // ----------------------------------------------------------------------
+    //
+    // ----------------------------------------------------------------------
+
     @SuppressWarnings({"unchecked", "rawtypes"})
     public List<MojoDescriptor> getMojos() {
         return (List) getComponents();
@@ -220,6 +287,14 @@ public class PluginDescriptor extends ComponentSetDescriptor implements Cloneabl
         artifactMap = null;
     }
 
+    public DependencyNode getDependencyNode() {
+        return dependencyNode;
+    }
+
+    public void setDependencyNode(DependencyNode dependencyNode) {
+        this.dependencyNode = dependencyNode;
+    }
+
     /**
      * The map of artifacts accessible by the versionlessKey, i.e. groupId:artifactId
      *
@@ -326,11 +401,15 @@ public class PluginDescriptor extends ComponentSetDescriptor implements Cloneabl
     }
 
     public Lifecycle getLifecycleMapping(String lifecycleId) throws IOException, XMLStreamException {
+        return getLifecycleMappings().get(lifecycleId);
+    }
+
+    public Map<String, Lifecycle> getLifecycleMappings() throws IOException, XMLStreamException {
         if (lifecycleMappings == null) {
             LifecycleConfiguration lifecycleConfiguration;
 
             try (InputStream input = getDescriptorStream(LIFECYCLE_DESCRIPTOR)) {
-                lifecycleConfiguration = new LifecycleMappingsStaxReader().read(input);
+                lifecycleConfiguration = new LifecycleStaxReader().read(input);
             }
 
             lifecycleMappings = new HashMap<>();
@@ -339,8 +418,7 @@ public class PluginDescriptor extends ComponentSetDescriptor implements Cloneabl
                 lifecycleMappings.put(lifecycle.getId(), lifecycle);
             }
         }
-
+        return lifecycleMappings;
-        return lifecycleMappings.get(lifecycleId);
     }
 
     private InputStream getDescriptorStream(String descriptor) throws IOException {
@@ -377,4 +455,33 @@ public class PluginDescriptor extends ComponentSetDescriptor implements Cloneabl
             addMojo(mojoDescriptor);
         }
     }
+
+    private volatile org.apache.maven.api.plugin.descriptor.PluginDescriptor pluginDescriptorV4;
+
+    public org.apache.maven.api.plugin.descriptor.PluginDescriptor getPluginDescriptorV4() {
+        if (pluginDescriptorV4 == null) {
+            synchronized (this) {
+                if (pluginDescriptorV4 == null) {
+                    pluginDescriptorV4 = org.apache.maven.api.plugin.descriptor.PluginDescriptor.newBuilder()
+                            .namespaceUri(null)
+                            .modelEncoding(null)
+                            .name(name)
+                            .description(description)
+                            .groupId(groupId)
+                            .artifactId(artifactId)
+                            .version(version)
+                            .goalPrefix(goalPrefix)
+                            .isolatedRealm(isIsolatedRealm())
+                            .inheritedByDefault(inheritedByDefault)
+                            .requiredJavaVersion(requiredJavaVersion)
+                            .requiredMavenVersion(requiredMavenVersion)
+                            .mojos(getMojos().stream()
+                                    .map(MojoDescriptor::getMojoDescriptorV4)
+                                    .collect(Collectors.toList()))
+                            .build();
+                }
+            }
+        }
+        return pluginDescriptorV4;
+    }
 }

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

@@ -21,6 +21,9 @@ package org.apache.maven.plugin.descriptor;
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamReader;
 
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
 import java.util.ArrayList;
@@ -28,8 +31,10 @@ import java.util.List;
 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.XmlPlexusConfiguration;
+import org.apache.maven.plugin.descriptor.io.PluginDescriptorStaxReader;
 import org.codehaus.plexus.component.repository.ComponentDependency;
 import org.codehaus.plexus.component.repository.ComponentRequirement;
 import org.codehaus.plexus.configuration.PlexusConfiguration;
@@ -38,16 +43,109 @@ import org.codehaus.plexus.configuration.PlexusConfigurationException;
 /**
  */
 public class PluginDescriptorBuilder {
+
+    public static final String PLUGIN_2_0_0 = "http://maven.apache.org/PLUGIN/2.0.0";
+    private static final int BUFFER_SIZE = 8192;
+
+    public interface StreamSupplier {
+        InputStream open() throws IOException;
+    }
+
+    public interface ReaderSupplier {
+        Reader open() throws IOException;
+    }
+
+    /**
+     * @deprecated use {@link #build(ReaderSupplier)}
+     */
+    @Deprecated
     public PluginDescriptor build(Reader reader) throws PlexusConfigurationException {
         return build(reader, null);
     }
 
+    /**
+     * @deprecated use {@link #build(ReaderSupplier, String)}
+     */
+    @Deprecated
     public PluginDescriptor build(Reader reader, String source) throws PlexusConfigurationException {
-        return build(source, buildConfiguration(reader));
+        return build(() -> reader, source);
     }
 
+    public PluginDescriptor build(ReaderSupplier readerSupplier) throws PlexusConfigurationException {
+        return build(readerSupplier, null);
+    }
+
+    public PluginDescriptor build(ReaderSupplier readerSupplier, String source) throws PlexusConfigurationException {
+        try (BufferedReader br = new BufferedReader(readerSupplier.open(), BUFFER_SIZE)) {
+            br.mark(BUFFER_SIZE);
+            XMLStreamReader xsr = WstxInputFactory.newFactory().createXMLStreamReader(br);
+            xsr.nextTag();
+            String nsUri = xsr.getNamespaceURI();
+            try (BufferedReader br2 = reset(readerSupplier, br)) {
+                xsr = WstxInputFactory.newFactory().createXMLStreamReader(br2);
+                return build(source, nsUri, xsr);
+            }
+        } catch (XMLStreamException | IOException e) {
+            throw new PlexusConfigurationException(e.getMessage(), e);
+        }
+    }
+
+    /**
+     * @deprecated use {@link #build(StreamSupplier, String)}
+     */
+    @Deprecated
     public PluginDescriptor build(InputStream input, String source) throws PlexusConfigurationException {
-        return build(source, buildConfiguration(input));
+        return build(() -> input, source);
+    }
+
+    public PluginDescriptor build(StreamSupplier inputSupplier) throws PlexusConfigurationException {
+        return build(inputSupplier, null);
+    }
+
+    public PluginDescriptor build(StreamSupplier inputSupplier, String source) throws PlexusConfigurationException {
+        try (BufferedInputStream bis = new BufferedInputStream(inputSupplier.open(), BUFFER_SIZE)) {
+            bis.mark(BUFFER_SIZE);
+            XMLStreamReader xsr = WstxInputFactory.newFactory().createXMLStreamReader(bis);
+            xsr.nextTag();
+            String nsUri = xsr.getNamespaceURI();
+            try (BufferedInputStream bis2 = reset(inputSupplier, bis)) {
+                xsr = WstxInputFactory.newFactory().createXMLStreamReader(bis2);
+                return build(source, nsUri, xsr);
+            }
+        } catch (XMLStreamException | IOException e) {
+            throw new PlexusConfigurationException(e.getMessage(), e);
+        }
+    }
+
+    private static BufferedInputStream reset(StreamSupplier inputSupplier, BufferedInputStream bis) throws IOException {
+        try {
+            bis.reset();
+            return bis;
+        } catch (IOException e) {
+            return new BufferedInputStream(inputSupplier.open(), BUFFER_SIZE);
+        }
+    }
+
+    private static BufferedReader reset(ReaderSupplier readerSupplier, BufferedReader br) throws IOException {
+        try {
+            br.reset();
+            return br;
+        } catch (IOException e) {
+            return new BufferedReader(readerSupplier.open(), BUFFER_SIZE);
+        }
+    }
+
+    private PluginDescriptor build(String source, String nsUri, XMLStreamReader xsr)
+            throws XMLStreamException, PlexusConfigurationException {
+        if (PLUGIN_2_0_0.equals(nsUri)) {
+            org.apache.maven.api.plugin.descriptor.PluginDescriptor pd =
+                    new PluginDescriptorStaxReader().read(xsr, true);
+            return new PluginDescriptor(pd);
+        } else {
+            XmlNode node = XmlNodeBuilder.build(xsr, true, null);
+            PlexusConfiguration cfg = XmlPlexusConfiguration.toPlexusConfiguration(node);
+            return build(source, cfg);
+        }
     }
 
     private PluginDescriptor build(String source, PlexusConfiguration c) throws PlexusConfigurationException {

pom.xml

@@ -162,10 +162,11 @@ under the License.
     <classWorldsVersion>2.6.0</classWorldsVersion>
     <commonsCliVersion>1.5.0</commonsCliVersion>
     <commonsIoVersion>2.11.0</commonsIoVersion>
-    <guiceVersion>5.1.0</guiceVersion>
+    <guiceVersion>6.0.0</guiceVersion>
     <guavaVersion>32.0.1-jre</guavaVersion>
     <guavafailureaccessVersion>1.0.1</guavafailureaccessVersion>
     <hamcrestVersion>2.2</hamcrestVersion>
+    <jakartaInjectApiVersion>2.0.1</jakartaInjectApiVersion>
     <jansiVersion>2.4.1</jansiVersion>
     <javaxAnnotationApiVersion>1.3.2</javaxAnnotationApiVersion>
     <junitVersion>5.10.1</junitVersion>
@@ -287,6 +288,11 @@ under the License.
         <version>${sisuVersion}</version>
         <classifier>no_asm</classifier>
       </dependency>
+      <dependency>
+        <groupId>jakarta.inject</groupId>
+        <artifactId>jakarta.inject-api</artifactId>
+        <version>${jakartaInjectApiVersion}</version>
+      </dependency>
       <dependency>
         <groupId>org.ow2.asm</groupId>
         <artifactId>asm</artifactId>

src/mdo/reader-stax.vm

@@ -27,6 +27,16 @@
 #set ( $rootUcapName = $Helper.capitalise( $root.name ) )
 #set ( $rootLcapName = $Helper.uncapitalise( $root.name ) )
 #
+#set ( $needXmlContext = false )
+#foreach ( $class in $model.allClasses )
+  #set ( $allFields = $Helper.xmlFields( $class ) )
+  #foreach ( $field in $allFields )
+    #if ( $Helper.xmlFieldMetadata( $field ).format )
+      #set ( $needXmlContext = true )
+    #end
+  #end
+#end
+#
 #MODELLO-VELOCITY#SAVE-OUTPUT-TO ${package.replace('.','/')}/${className}.java
 // =================== DO NOT EDIT THIS FILE ====================
 //  Generated by Modello Velocity from ${template}
@@ -38,9 +48,15 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
 import java.text.DateFormat;
+#if ( $needXmlContext )
+import java.util.ArrayDeque;
+#end
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
+#if ( $needXmlContext )
+import java.util.Deque;
+#end
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -470,6 +486,9 @@ public class ${className} {
     public ${root.name} read(XMLStreamReader parser, boolean strict, InputSource source) throws XMLStreamException {
 #else
     public ${root.name} read(XMLStreamReader parser, boolean strict) throws XMLStreamException {
+#end
+#if ( $needXmlContext )
+        Deque<Object> context = new ArrayDeque<>();
 #end
         $rootUcapName $rootLcapName = null;
         int eventType = parser.getEventType();
@@ -484,6 +503,8 @@ public class ${className} {
                 }
 #if ( $locationTracking )
                 $rootLcapName = parse${rootUcapName}(parser, strict, source);
+#elseif ( $needXmlContext )
+                $rootLcapName = parse${rootUcapName}(parser, strict, context);
 #else
                 $rootLcapName = parse${rootUcapName}(parser, strict);
 #end
@@ -505,6 +526,8 @@ public class ${className} {
   #set ( $allFields = $Helper.xmlFields( $class ) )
   #if ( $locationTracking )
     private ${classUcapName} parse${classUcapName}(XMLStreamReader parser, boolean strict, InputSource source) throws XMLStreamException {
+  #elseif ( $needXmlContext )
+    private ${classUcapName} parse${classUcapName}(XMLStreamReader parser, boolean strict, Deque<Object> context) throws XMLStreamException {
   #else
     private ${classUcapName} parse${classUcapName}(XMLStreamReader parser, boolean strict) throws XMLStreamException {
   #end
@@ -553,6 +576,9 @@ public class ${className} {
     #if ( $Helper.isFlatItems( $field ) )
         List<$field.to> ${field.name} = new ArrayList<>();
     #end
+  #end
+  #if ( $needXmlContext )
+        context.addLast( ${classLcapName} );
   #end
         while ((strict ? parser.nextTag() : nextTag(parser)) == XMLStreamReader.START_ELEMENT) {
             String childName = checkDuplicate(parser.getLocalName(), parser, parsed);
@@ -564,7 +590,7 @@ public class ${className} {
             switch (childName) {
   #set( $ift = "if" )
   #foreach ( $field in $allFields )
-    #if ( ! $Helper.xmlFieldMetadata( $field ).attribute && ! $Helper.xmlFieldMetadata( $field ).transient )
+    #if ( ! $Helper.xmlFieldMetadata( $field ).attribute && ! $Helper.xmlFieldMetadata( $field ).transient && ! $Helper.xmlFieldMetadata( $field ).format )
       #set ( $fieldTagName = $Helper.xmlFieldMetadata( $field ).tagName )
       #if ( ! $fieldTagName )
         #set ( $fieldTagName = $field.name )
@@ -629,6 +655,8 @@ public class ${className} {
       #elseif ( $field.to && $field.multiplicity == "1" )
         #if ( $locationTracking )
                     ${classLcapName}.${field.name}(parse${field.toClass.name}(parser, strict, source));
+        #elseif ( $needXmlContext )
+                    ${classLcapName}.${field.name}(parse${field.toClass.name}(parser, strict, context));
         #else
                     ${classLcapName}.${field.name}(parse${field.toClass.name}(parser, strict));
         #end
@@ -642,6 +670,8 @@ public class ${className} {
                         if ("${Helper.singular($fieldTagName)}".equals(parser.getLocalName())) {
         #if ( $locationTracking )
                             ${field.name}.add(parse${field.toClass.name}(parser, strict, source));
+        #elseif ( $needXmlContext )
+                            ${field.name}.add(parse${field.toClass.name}(parser, strict, context));
         #else
                             ${field.name}.add(parse${field.toClass.name}(parser, strict));
         #end
@@ -670,11 +700,19 @@ public class ${className} {
             }
   #end
         }
+  #if ( $needXmlContext )
+        context.removeLast();
+  #end
   #foreach ( $field in $allFields )
     #if ( $Helper.isFlatItems( $field ) )
         ${classLcapName}.${field.name}(${field.name});
     #end
   #end
+  #foreach ( $field in $allFields )
+    #if ( $Helper.xmlFieldMetadata( $field ).format )
+        ${classLcapName}.${field.name}($Helper.xmlFieldMetadata( $field ).format);
+    #end
+  #end
   #if ( $class == $root )
         ${classLcapName}.namespaceUri(parser.getNamespaceURI());
         ${classLcapName}.modelEncoding(parser.getEncoding());

src/mdo/writer-stax.vm

@@ -224,7 +224,7 @@ public class ${className} {
             serializer.writeStartElement(namespace, tagName);
   #end
   #foreach ( $field in $allFields )
-    #if ( $Helper.xmlFieldMetadata( $field ).attribute )
+    #if ( $Helper.xmlFieldMetadata( $field ).attribute && ! $Helper.xmlFieldMetadata( $field ).format )
       #set ( $fieldTagName = $Helper.xmlFieldMetadata( $field ).tagName )
       #set ( $fieldCapName = $Helper.capitalise( $field.name ) )
       #if ( $field.type == "String" )
@@ -242,7 +242,8 @@ public class ${className} {
     #end
   #end
   #foreach ( $field in $allFields )
-    #if ( ! $Helper.xmlFieldMetadata( $field ).attribute && ! $Helper.xmlFieldMetadata( $field ).transient )
+    #if ( ! $Helper.xmlFieldMetadata( $field ).attribute && ! $Helper.xmlFieldMetadata( $field ).transient
+                 && ! $Helper.xmlFieldMetadata( $field ).format )
       #set ( $fieldTagName = $Helper.xmlFieldMetadata( $field ).tagName )
       #if ( ! $fieldTagName )
         #set ( $fieldTagName = $field.name )