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

package org.apache.maven.plugin;

/*
 * 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.
 */

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.util.List;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.execution.MojoExecutionEvent;
import org.apache.maven.execution.MojoExecutionListener;
import org.apache.maven.execution.scope.internal.MojoExecutionScope;
import org.apache.maven.model.Plugin;
import org.apache.maven.plugin.descriptor.MojoDescriptor;
import org.apache.maven.plugin.descriptor.PluginDescriptor;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.classworlds.realm.ClassRealm;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.repository.RemoteRepository;

// TODO the antrun plugin has its own configurator, the only plugin that does. might need to think about how that works
// TODO remove the coreArtifactFilterManager

@Component( role = BuildPluginManager.class )
public class DefaultBuildPluginManager
    implements BuildPluginManager
{

    @Requirement
    private MavenPluginManager mavenPluginManager;

    @Requirement
    private LegacySupport legacySupport;

    @Requirement
    private MojoExecutionScope scope;

    private MojoExecutionListener mojoExecutionListener;

    // this tricks plexus-component-metadata generate required metadata
    @Requirement( role = MojoExecutionListener.class )
    private List<MojoExecutionListener> mojoExecutionListeners;

    public void setMojoExecutionListeners( final List<MojoExecutionListener> listeners )
    {
        this.mojoExecutionListeners = listeners;
        this.mojoExecutionListener = new CompoundMojoExecutionListener( listeners );
    }

    /**
     * @param plugin
     * @param repositories
     * @param session
     * @return PluginDescriptor The component descriptor for the Maven plugin.
     * @throws PluginNotFoundException The plugin could not be found in any repositories.
     * @throws PluginResolutionException The plugin could be found but could not be resolved.
     * @throws InvalidPluginDescriptorException
     */
    public PluginDescriptor loadPlugin( Plugin plugin, List<RemoteRepository> repositories,
                                        RepositorySystemSession session )
        throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException,
        InvalidPluginDescriptorException
    {
        return mavenPluginManager.getPluginDescriptor( plugin, repositories, session );
    }

    // ----------------------------------------------------------------------
    // Mojo execution
    // ----------------------------------------------------------------------

    public void executeMojo( MavenSession session, MojoExecution mojoExecution )
        throws MojoFailureException, MojoExecutionException, PluginConfigurationException, PluginManagerException
    {
        MavenProject project = session.getCurrentProject();

        MojoDescriptor mojoDescriptor = mojoExecution.getMojoDescriptor();

        Mojo mojo = null;

        ClassRealm pluginRealm;
        try
        {
            pluginRealm = getPluginRealm( session, mojoDescriptor.getPluginDescriptor() );
        }
        catch ( PluginResolutionException e )
        {
            throw new PluginExecutionException( mojoExecution, project, e );
        }

        ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader( pluginRealm );

        MavenSession oldSession = legacySupport.getSession();

        scope.enter();

        try
        {
            scope.seed( MavenProject.class, project );
            scope.seed( MojoExecution.class, mojoExecution );

            mojo = mavenPluginManager.getConfiguredMojo( Mojo.class, session, mojoExecution );

            legacySupport.setSession( session );

            // NOTE: DuplicateArtifactAttachmentException is currently unchecked, so be careful removing this try/catch!
            // This is necessary to avoid creating compatibility problems for existing plugins that use
            // MavenProjectHelper.attachArtifact(..).
            try
            {
                MojoExecutionEvent mojoExecutionEvent = new MojoExecutionEvent( session, project, mojoExecution, mojo );

                mojoExecutionListener.beforeMojoExecution( mojoExecutionEvent );

                mojo.execute();

                mojoExecutionListener.afterMojoExecutionSuccess( mojoExecutionEvent );
            }
            catch ( ClassCastException e )
            {
                // to be processed in the outer catch block
                throw e;
            }
            catch ( RuntimeException e )
            {
                throw new PluginExecutionException( mojoExecution, project, e );
            }
        }
        catch ( PluginContainerException e )
        {
            mojoExecutionListener.afterExecutionFailure( new MojoExecutionEvent( session, project, mojoExecution, mojo,
                                                                                 e ) );

            throw new PluginExecutionException( mojoExecution, project, e );
        }
        catch ( NoClassDefFoundError e )
        {
            mojoExecutionListener.afterExecutionFailure( new MojoExecutionEvent( session, project, mojoExecution, mojo,
                                                                                 e ) );

            ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
            PrintStream ps = new PrintStream( os );
            ps.println( "A required class was missing while executing " + mojoDescriptor.getId() + ": "
                + e.getMessage() );
            pluginRealm.display( ps );

            Exception wrapper = new PluginContainerException( mojoDescriptor, pluginRealm, os.toString(), e );

            throw new PluginExecutionException( mojoExecution, project, wrapper );
        }
        catch ( LinkageError e )
        {
            mojoExecutionListener.afterExecutionFailure( new MojoExecutionEvent( session, project, mojoExecution, mojo,
                                                                                 e ) );

            ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
            PrintStream ps = new PrintStream( os );
            ps.println( "An API incompatibility was encountered while executing " + mojoDescriptor.getId() + ": "
                + e.getClass().getName() + ": " + e.getMessage() );
            pluginRealm.display( ps );

            Exception wrapper = new PluginContainerException( mojoDescriptor, pluginRealm, os.toString(), e );

            throw new PluginExecutionException( mojoExecution, project, wrapper );
        }
        catch ( ClassCastException e )
        {
            mojoExecutionListener.afterExecutionFailure( new MojoExecutionEvent( session, project, mojoExecution, mojo,
                                                                                 e ) );

            ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
            PrintStream ps = new PrintStream( os );
            ps.println( "A type incompatibility occurred while executing " + mojoDescriptor.getId() + ": "
                + e.getMessage() );
            pluginRealm.display( ps );

            throw new PluginExecutionException( mojoExecution, project, os.toString(), e );
        }
        catch ( RuntimeException e )
        {
            mojoExecutionListener.afterExecutionFailure( new MojoExecutionEvent( session, project, mojoExecution, mojo,
                                                                                 e ) );

            throw e;
        }
        finally
        {
            mavenPluginManager.releaseMojo( mojo, mojoExecution );

            scope.exit();

            Thread.currentThread().setContextClassLoader( oldClassLoader );

            legacySupport.setSession( oldSession );
        }
    }

    /**
     * TODO pluginDescriptor classRealm and artifacts are set as a side effect of this
     *      call, which is not nice.
     * @throws PluginResolutionException
     */
    public ClassRealm getPluginRealm( MavenSession session, PluginDescriptor pluginDescriptor )
        throws PluginResolutionException, PluginManagerException
    {
        ClassRealm pluginRealm = pluginDescriptor.getClassRealm();
        if ( pluginRealm != null )
        {
            return pluginRealm;
        }

        mavenPluginManager.setupPluginRealm( pluginDescriptor, session, null, null, null );

        return pluginDescriptor.getClassRealm();
    }

    public MojoDescriptor getMojoDescriptor( Plugin plugin, String goal, List<RemoteRepository> repositories,
                                             RepositorySystemSession session )
        throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException,
        MojoNotFoundException, InvalidPluginDescriptorException
    {
        return mavenPluginManager.getMojoDescriptor( plugin, goal, repositories, session );
    }

}