PR: MNG-2293

Submitted by: Jerome Lacoste
Reviewed by: Kenney Westerhof
Modifications: minor cosmetic changes.

Add an 'implementation' parameter to @parameter annotation, so
a default implementation can be specified in Mojo's in case the Mojo parameter
is an interface.



git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@413054 13f79535-47bb-0310-9956-ffa450edef68

integration-tests/maven-core-it-plugin/src/main/java/org/apache/maven/plugin/coreit/Bla.java

@@ -0,0 +1,7 @@
+package org.apache.maven.plugin.coreit;
+
+/**
+ */
+public interface Bla
+{
+}

integration-tests/maven-core-it-plugin/src/main/java/org/apache/maven/plugin/coreit/ParameterImplementationMojo.java

@@ -0,0 +1,42 @@
+package org.apache.maven.plugin.coreit;
+
+import org.apache.maven.plugin.AbstractMojo;
+import org.apache.maven.plugin.MojoExecutionException;
+
+/**
+ * Check that we correctly use the implementation parameter. See MNG-2293
+ *
+ * @goal param-implementation
+ * @description Prints out the name of the implementation of the bla field.
+ */
+public class ParameterImplementationMojo
+    extends AbstractMojo
+{
+
+    /**
+     * @parameter implementation="org.apache.maven.plugin.coreit.sub.MyBla"
+     * @required
+     */
+    private Bla bla;
+
+    /**
+     * The expected value of bla.toString().
+     *
+     * @parameter
+     * @required
+     */
+    private String expected;
+
+    public void execute()
+        throws MojoExecutionException
+    {
+
+        getLog().info( "bla: " + bla );
+
+        if ( ! expected.equals( bla.toString() ) )
+        {
+            throw new MojoExecutionException( "Expected '" + expected + "'; found '" + bla + "'" );
+        }
+    }
+
+}

integration-tests/maven-core-it-plugin/src/main/java/org/apache/maven/plugin/coreit/sub/MyBla.java

@@ -0,0 +1,26 @@
+package org.apache.maven.plugin.coreit.sub;
+
+import org.apache.maven.plugin.coreit.Bla;
+
+/**
+ */
+public class MyBla
+    implements Bla
+{
+    private String field;
+
+    public String getField()
+    {
+        return field; 
+    }
+
+    public void setField( String field )
+    {
+        this.field = field; 
+    }
+
+    public String toString()
+    {
+        return getClass() + "-" + field;
+    }
+}

maven-core-it/README.txt

@@ -1,3 +1,11 @@
+Notes:
+- today, 3 sets of integration tests, categorized by their ids (it0xxx, it1xxx, it2xxx). 
+  see below for what these groups represent
+- creating a new test:
+ - you can add mojos to the integration-tests plugins/maven-core-it-plugin
+ - add log.txt and target to your it test svn ignore list
+
+Details:
 -------------------------------------------------------------------------------
 it0000: The simplest of builds. We have one application class and one test
         class. There are no resources, no source generation, no resource
@@ -285,6 +293,8 @@ it0104: Verify that plugin configurations are resolved correctly, particularly
         when they contain ${project.build.directory} in the string value of a 
         Map.Entry.
 
+it0107: Verify that default implementation of an implementation for a complex object works as 
+        expected [MNG-2293]
 -------------------------------------------------------------------------------
 
 - generated sources

maven-core-it/integration-tests.txt

@@ -1,3 +1,4 @@
+it0107
 #it0104 Commenting out, not fixed until post-2.0.4, due to dependency on new plexus-container-default version.
 it0103
 it0102

maven-core-it/it0107/cli-options.txt

@@ -0,0 +1 @@
+-X

maven-core-it/it0107/goals.txt

@@ -0,0 +1 @@
+core-it:param-implementation

maven-core-it/it0107/pom.xml

@@ -0,0 +1,22 @@
+<model>
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.apache.maven</groupId>
+  <artifactId>maven-core-it0107</artifactId>
+  <packaging>pom</packaging>
+  <version>3.8.1</version>
+  <build>
+    <plugins>
+      <plugin>
+        <artifactId>maven-core-it-plugin</artifactId>
+        <version>1.1-SNAPSHOT</version>
+        <goals>
+          <goal>param-implementation</goal>
+        </goals>
+        <configuration>
+          <bla><field>foobar</field></bla>
+          <expected>class org.apache.maven.plugin.coreit.sub.MyBla-foobar</expected>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</model>

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

@@ -872,6 +872,7 @@ public class DefaultPluginManager
 
                 String paramName = parameter.getName();
                 String alias = parameter.getAlias();
+                String implementation = parameter.getImplementation();
 
                 PlexusConfiguration pomConfig = fromPom.getChild( paramName );
                 PlexusConfiguration aliased = null;
@@ -895,7 +896,7 @@ public class DefaultPluginManager
                     pomConfig = buildTopDownMergedConfiguration( pomConfig, aliased );
                 }
 
-                boolean addedPomConfig = false;
+                PlexusConfiguration toAdd = null;
 
                 if ( pomConfig != null )
                 {
@@ -903,15 +904,29 @@ public class DefaultPluginManager
 
                     if ( StringUtils.isNotEmpty( pomConfig.getValue( null ) ) || pomConfig.getChildCount() > 0 )
                     {
-                        result.addChild( pomConfig );
+                        toAdd = pomConfig;
-
-                        addedPomConfig = true;
                     }
                 }
 
-                if ( !addedPomConfig && mojoConfig != null )
+                if ( toAdd == null && mojoConfig != null )
                 {
-                    result.addChild( copyConfiguration( mojoConfig ) );
+                    toAdd = copyConfiguration( mojoConfig );
+                }
+
+                if ( toAdd != null )
+                {
+                    if ( implementation != null
+                        && toAdd.getAttribute( "implementation", null ) == null )
+                    {
+
+                        XmlPlexusConfiguration implementationConf = new XmlPlexusConfiguration( paramName );
+
+                        implementationConf.setAttribute( "implementation", parameter.getImplementation() );
+
+                        toAdd = buildTopDownMergedConfiguration( toAdd, implementationConf  );
+                    }
+
+                    result.addChild( toAdd );
                 }
             }
         }

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

@@ -40,6 +40,8 @@ public class Parameter
 
     private String defaultValue;
 
+    private String implementation;
+
     private Requirement requirement;
 
     // ----------------------------------------------------------------------
@@ -160,4 +162,14 @@ public class Parameter
     {
         this.requirement = requirement;
     }
+
+    public String getImplementation()
+    {
+        return implementation;
+    }
+
+    public void setImplementation( String implementation )
+    {
+        this.implementation = implementation;
+    }
 }

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

@@ -250,6 +250,8 @@ public class PluginDescriptorBuilder
 
             parameter.setDeprecated( d.getChild( "deprecated" ).getValue() );
 
+            parameter.setImplementation( d.getChild( "implementation" ).getValue() );
+
             parameters.add( parameter );
         }
 

maven-plugin-tools/maven-plugin-tools-api/src/main/java/org/apache/maven/tools/plugin/generator/PluginDescriptorGenerator.java

@@ -335,6 +335,11 @@ public class PluginDescriptorGenerator
                         element( w, "deprecated", parameter.getDeprecated() );
                     }
 
+                    if ( parameter.getImplementation() != null )
+                    {
+                        element( w, "implementation", parameter.getImplementation() );
+                    }
+
                     element( w, "required", Boolean.toString( parameter.isRequired() ) );
 
                     element( w, "editable", Boolean.toString( parameter.isEditable() ) );

maven-plugin-tools/maven-plugin-tools-java/src/main/java/org/apache/maven/tools/plugin/extractor/java/JavaMojoDescriptorExtractor.java

@@ -59,6 +59,11 @@ public class JavaMojoDescriptorExtractor
 
     public static final String PARAMETER_DEFAULT_VALUE = "default-value";
 
+    /**
+     * This defines the default implementation in the case the parameter type is an interface.
+     */
+    public static final String PARAMETER_IMPLEMENTATION = "implementation";
+
     /**
      * This indicates the base name of the bean properties used to read/write this parameter's value.
      * So:
@@ -422,6 +427,9 @@ public class JavaMojoDescriptorExtractor
                 }
 
                 pd.setDefaultValue( parameter.getNamedParameter( PARAMETER_DEFAULT_VALUE ) );
+
+                pd.setImplementation( parameter.getNamedParameter( PARAMETER_IMPLEMENTATION ) );
+                
             }
 
             mojoDescriptor.addParameter( pd );

maven-plugin-tools/maven-plugin-tools-java/src/test/java/org/apache/maven/tools/plugin/extractor/java/JavaMojoDescriptorExtractorTest.java

@@ -19,12 +19,16 @@ package org.apache.maven.tools.plugin.extractor.java;
 import junit.framework.TestCase;
 import org.apache.maven.model.Model;
 import org.apache.maven.project.MavenProject;
+import org.apache.maven.plugin.descriptor.MojoDescriptor;
+import org.apache.maven.plugin.descriptor.Parameter;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
 
 import java.io.File;
 import java.net.URL;
 import java.util.List;
 
+import source2.sub.MyBla;
+
 /**
  * @author jdcasey
  */
@@ -56,6 +60,40 @@ public class JavaMojoDescriptorExtractorTest
         assertEquals( 2, results.size() );
     }
 
+    public void testShouldPropagateImplementationParameter()
+        throws Exception
+    {
+        JavaMojoDescriptorExtractor extractor = new JavaMojoDescriptorExtractor();
+
+        File sourceFile = fileOf( "dir-flag.txt" );
+        System.out.println( "found source file: " + sourceFile );
+
+        File dir = sourceFile.getParentFile();
+
+        Model model = new Model();
+        model.setArtifactId( "maven-unitTesting-plugin" );
+
+        MavenProject project = new MavenProject( model );
+
+        project.setFile( new File( dir, "pom.xml" ) );
+        project.addCompileSourceRoot( new File( dir, "source2" ).getPath() );
+
+        PluginDescriptor pluginDescriptor = new PluginDescriptor();
+        pluginDescriptor.setGoalPrefix( "test" );
+        List results = extractor.execute( project, pluginDescriptor );
+        assertEquals( 1, results.size() );
+
+        MojoDescriptor mojoDescriptor = (MojoDescriptor) results.get( 0 );
+
+        List parameters = mojoDescriptor.getParameters();
+
+        assertEquals( 1, parameters.size() );
+
+        Parameter parameter = (Parameter) parameters.get( 0 );
+
+        assertEquals( MyBla.class.getName(), parameter.getImplementation() );
+    }
+
     private File fileOf( String classpathResource )
     {
         ClassLoader cl = Thread.currentThread().getContextClassLoader();

maven-plugin-tools/maven-plugin-tools-java/src/test/resources/source2/Bla.java

@@ -0,0 +1,5 @@
+package source2;
+
+public interface Bla
+{
+}

maven-plugin-tools/maven-plugin-tools-java/src/test/resources/source2/JavaExtractorTestThree.java

@@ -0,0 +1,31 @@
+package source2;
+
+import org.apache.maven.plugin.AbstractMojo;
+
+/**
+ * Tests the implementation argument of the parameter annotation.
+ *
+ * @goal ideaThree
+ * @requiresDependencyResolution compile
+ */
+public class JavaExtractorTestThree
+    extends AbstractMojo
+{
+    /**
+     * @parameter implementation=source2.sub.MyBla
+     * @required
+     */
+    private Bla bla;
+
+    public JavaExtractorTestThree()
+    {
+    }
+
+    public void execute()
+    {
+        if ( getLog() != null )
+        {
+            getLog().info( "bla: " + bla );
+        }
+    }
+}

maven-plugin-tools/maven-plugin-tools-java/src/test/resources/source2/sub/MyBla.java

@@ -0,0 +1,8 @@
+package source2.sub;
+
+import source2.Bla;
+
+public class MyBla
+    implements Bla
+{
+}

maven-project/src/test/java/org/apache/maven/project/validation/DefaultModelValidatorTest.java

@@ -216,7 +216,7 @@ public class DefaultModelValidatorTest
     private ModelValidationResult validate( String testName )
         throws Exception
     {
-        Reader input = new FileReader( getFileForClasspathResource( "/validation/" + testName ) );
+        Reader input = new FileReader( getFileForClasspathResource( "validation/" + testName ) );
 
         MavenXpp3Reader reader = new MavenXpp3Reader();