package org.apache.maven.plugins.shade.mojo;

 /*

  * 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.File;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.Writer;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.LinkedHashSet;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import org.apache.maven.artifact.Artifact;

 import org.apache.maven.artifact.factory.ArtifactFactory;

 import org.apache.maven.artifact.metadata.ArtifactMetadataSource;

 import org.apache.maven.artifact.repository.ArtifactRepository;

 import org.apache.maven.artifact.resolver.ArtifactCollector;

 import org.apache.maven.artifact.resolver.ArtifactNotFoundException;

 import org.apache.maven.artifact.resolver.ArtifactResolutionException;

 import org.apache.maven.artifact.resolver.ArtifactResolver;

 import org.apache.maven.model.Dependency;

 import org.apache.maven.model.Exclusion;

 import org.apache.maven.model.Model;

 import org.apache.maven.plugin.AbstractMojo;

 import org.apache.maven.plugin.MojoExecutionException;

 import org.apache.maven.plugins.shade.Shader;

 import org.apache.maven.plugins.shade.filter.SimpleFilter;

 import org.apache.maven.plugins.shade.pom.PomWriter;

 import org.apache.maven.plugins.shade.relocation.SimpleRelocator;

 import org.apache.maven.plugins.shade.resource.ResourceTransformer;

 import org.apache.maven.project.MavenProject;

 import org.apache.maven.project.MavenProjectBuilder;

 import org.apache.maven.project.MavenProjectHelper;

 import org.apache.maven.project.ProjectBuildingException;

 import org.apache.maven.shared.dependency.tree.DependencyNode;

 import org.apache.maven.shared.dependency.tree.DependencyTreeBuilder;

 import org.apache.maven.shared.dependency.tree.DependencyTreeBuilderException;

 import org.codehaus.plexus.util.FileUtils;

 import org.codehaus.plexus.util.IOUtil;

 import org.codehaus.plexus.util.WriterFactory;

 /**

  * Mojo that performs shading delegating to the Shader component.

  *

  * @author Jason van Zyl

  * @author Mauro Talevi

  * @author David Blevins

  * @author Hiram Chirino

  * @goal shade

  * @phase package

  * @requiresDependencyResolution runtime

  */

 public class ShadeMojo

     extends AbstractMojo

 {

     /**

      * @parameter default-value="${project}"

      * @readonly

      * @required

      */

     private MavenProject project;

     /**

      * @component

      * @required

      * @readonly

      */

     private MavenProjectHelper projectHelper;

     /**

      * @component

      * @required

      * @readonly

      */

     private Shader shader;

     /**

      * The dependency tree builder to use.

      *

      * @component

      * @required

      * @readonly

      */

     private DependencyTreeBuilder dependencyTreeBuilder;

     /**

      * ProjectBuilder, needed to create projects from the artifacts.

      *

      * @component

      * @required

      * @readonly

      */

     private MavenProjectBuilder mavenProjectBuilder;

     /**

      * The artifact metadata source to use.

      *

      * @component

      * @required

      * @readonly

      */

     private ArtifactMetadataSource artifactMetadataSource;

     /**

      * The artifact collector to use.

      *

      * @component

      * @required

      * @readonly

      */

     private ArtifactCollector artifactCollector;

     /**

      * Remote repositories which will be searched for source attachments.

      *

      * @parameter default-value="${project.remoteArtifactRepositories}"

      * @required

      * @readonly

      */

     protected List remoteArtifactRepositories;

     /**

      * Local maven repository.

      *

      * @parameter default-value="${localRepository}"

      * @required

      * @readonly

      */

     protected ArtifactRepository localRepository;

     /**

      * Artifact factory, needed to download source jars for inclusion in classpath.

      *

      * @component

      * @required

      * @readonly

      */

     protected ArtifactFactory artifactFactory;

     /**

      * Artifact resolver, needed to download source jars for inclusion in classpath.

      *

      * @component

      * @required

      * @readonly

      */

     protected ArtifactResolver artifactResolver;

     /**

      * Artifacts to include/exclude from the final artifact. Artifacts are denoted by composite identifiers of the

      * general form <code>groupId:artifactId:type:classifier</code>. Since version 1.3, the wildcard characters '*' and '?' can be used

      * within the sub parts of those composite identifiers to do pattern matching. For convenience, the syntax

      * <code>groupId</code> is equivalent to <code>groupId:*:*:*</code>, <code>groupId:artifactId</code> is equivalent

      * to <code>groupId:artifactId:*:*</code> and <code>groupId:artifactId:classifier</code> is equivalent to

      * <code>groupId:artifactId:*:classifier</code>.

      * 

      * @parameter

      */

     private ArtifactSet artifactSet;

     /**

      * Packages to be relocated.

      *

      * @parameter

      */

     private PackageRelocation[] relocations;

     /**

      * Resource transformers to be used.

      *

      * @parameter

      */

     private ResourceTransformer[] transformers;

     /**

      * Archive Filters to be used. Allows you to specify an artifact in the form of a composite identifier as used by

      * {@link #artifactSet} and a set of include/exclude file patterns for filtering which contents of the archive are

      * added to the shaded jar. From a logical perspective, includes are processed before excludes, thus it's possible

      * to use an include to collect a set of files from the archive then use excludes to further reduce the set. By

      * default, all files are included and no files are excluded. If multiple filters apply to an artifact, the

      * intersection of the matched files will be included in the final JAR.

      * 

      * @parameter

      */

     private ArchiveFilter[] filters;

     /**

      * The destination directory for the shaded artifact.

      *

      * @parameter default-value="${project.build.directory}"

      */

     private File outputDirectory;

     /**

      * The name of the shaded artifactId.

      * 

      * If you like to change the name of the native artifact, you may use the <build><finalName> setting.

      * If this is set to something different than <build><finalName>, no file replacement

      * will be performed, even if shadedArtifactAttached is being used.

      *

      * @parameter expression="${finalName}"

      */

     private String finalName;

     /**

      * The name of the shaded artifactId. So you may want to use a different artifactId and keep

      * the standard version. If the original artifactId was "foo" then the final artifact would

      * be something like foo-1.0.jar. So if you change the artifactId you might have something

      * like foo-special-1.0.jar.

      *

      * @parameter expression="${shadedArtifactId}" default-value="${project.artifactId}"

      */

     private String shadedArtifactId;

     /**

      * If specified, this will include only artifacts which have groupIds which

      * start with this.

      *

      * @parameter expression="${shadedGroupFilter}"

      */

     private String shadedGroupFilter;

     /**

      * Defines whether the shaded artifact should be attached as classifier to

      * the original artifact.  If false, the shaded jar will be the main artifact

      * of the project

      *

      * @parameter expression="${shadedArtifactAttached}" default-value="false"

      */

     private boolean shadedArtifactAttached;

     /**

      * Flag whether to generate a simplified POM for the shaded artifact. If set to <code>true</code>, dependencies that

      * have been included into the uber JAR will be removed from the <code>&lt;dependencies&gt;</code> section of the

      * generated POM. The reduced POM will be named <code>dependency-reduced-pom.xml</code> and is stored into the same

      * directory as the shaded artifact.

      *

      * @parameter expression="${createDependencyReducedPom}" default-value="true"

      */

     private boolean createDependencyReducedPom;

     /**

      * When true, dependencies are kept in the pom but with scope 'provided'; when false,

      * the dependency is removed.

      *

      * @parameter expression="${keepDependenciesWithProvidedScope}" default-value="false"

      */

     private boolean keepDependenciesWithProvidedScope;

     /**

      * When true, transitive deps of removed dependencies are promoted to direct dependencies.

      * This should allow the drop in replacement of the removed deps with the new shaded

      * jar and everything should still work.

      *

      * @parameter expression="${promoteTransitiveDependencies}" default-value="false"

      */

     private boolean promoteTransitiveDependencies;

     /**

      * The name of the classifier used in case the shaded artifact is attached.

      *

      * @parameter expression="${shadedClassifierName}" default-value="shaded"

      */

     private String shadedClassifierName;

     /**

      * When true, it will attempt to create a sources jar as well

      *

      * @parameter expression="${createSourcesJar}" default-value="false"

      */

     private boolean createSourcesJar;

     /**

      * The path to the output file for the shaded artifact. When this parameter is set, the created archive will neither

      * replace the project's main artifact nor will it be attached. Hence, this parameter causes the parameters

      * {@link #finalName}, {@link #shadedArtifactAttached}, {@link #shadedClassifierName} and

      * {@link #createDependencyReducedPom} to be ignored when used.

      * 

      * @parameter

      * @since 1.3

      */

     private File outputFile;

     /** @throws MojoExecutionException  */

     public void execute()

         throws MojoExecutionException

     {

         Set artifacts = new LinkedHashSet();

         Set artifactIds = new LinkedHashSet();

         Set sourceArtifacts = new LinkedHashSet();

         ArtifactSelector artifactSelector = new ArtifactSelector( artifactSet, shadedGroupFilter );

         if ( artifactSelector.isSelected( project.getArtifact() ) && !"pom".equals( project.getArtifact().getType() ) )

         {

             if ( project.getArtifact().getFile() == null )

             {

                 getLog().error( "The project main artifact does not exist. This could have the following" );

                 getLog().error( "reasons:" );

                 getLog().error( "- You have invoked the goal directly from the command line. This is not" );

                 getLog().error( "  supported. Please add the goal to the default lifecycle via an" );

                 getLog().error( "  <execution> element in your POM and use \"mvn package\" to have it run." );

                 getLog().error( "- You have bound the goal to a lifecycle phase before \"package\". Please" );

                 getLog().error( "  remove this binding from your POM such that the goal will be run in" );

                 getLog().error( "  the proper phase." );

                 throw new MojoExecutionException( "Failed to create shaded artifact.",

                                                   new IllegalStateException( "Project main artifact does not exist." ) );

             }

             artifacts.add( project.getArtifact().getFile() );

             if ( createSourcesJar )

             {

                 File file = shadedSourcesArtifactFile();

                 if ( file.isFile() )

                 {

                     sourceArtifacts.add( file );

                 }

             }

         }

         for ( Iterator it = project.getArtifacts().iterator(); it.hasNext(); )

         {

             Artifact artifact = (Artifact) it.next();

             if ( !artifactSelector.isSelected( artifact ) )

             {

                 getLog().info( "Excluding " + artifact.getId() + " from the shaded jar." );

                 continue;

             }

             if ( "pom".equals( artifact.getType() ) )

             {

                 getLog().info( "Skipping pom dependency " + artifact.getId() + " in the shaded jar." );

                 continue;

             }

             getLog().info( "Including " + artifact.getId() + " in the shaded jar." );

             artifacts.add( artifact.getFile() );

             artifactIds.add( getId( artifact ) );

             if ( createSourcesJar )

             {

                 File file = resolveArtifactSources( artifact );

                 if ( file != null )

                 {

                     sourceArtifacts.add( file );

                 }

             }

         }

         File outputJar = ( outputFile != null ) ? outputFile : shadedArtifactFileWithClassifier();

         File sourcesJar = shadedSourceArtifactFileWithClassifier();

         // Now add our extra resources

         try

         {

             List filters = getFilters();

             List relocators = getRelocators();

             List resourceTransformers = getResourceTransformers();

             shader.shade( artifacts, outputJar, filters, relocators, resourceTransformers );

             if ( createSourcesJar )

             {

                 shader.shade( sourceArtifacts, sourcesJar, filters, relocators, resourceTransformers );

             }

             if ( outputFile == null )

             {

                 boolean renamed = false;

                 // rename the output file if a specific finalName is set

                 // but don't rename if the finalName is the <build><finalName>

                 // because this will be handled implicitely later

                 if ( finalName != null && finalName.length() > 0 && !finalName.equals( project.getBuild().getFinalName() ) )

                 {

                     String finalFileName = finalName + "." + project.getArtifact().getArtifactHandler().getExtension();

                     File finalFile = new File( outputDirectory, finalFileName );

                     replaceFile( finalFile, outputJar );

                     outputJar = finalFile;

                     renamed = true;

                 }

                 if ( shadedArtifactAttached )

                 {

                     getLog().info( "Attaching shaded artifact." );

                     projectHelper.attachArtifact( project, project.getArtifact().getType(), shadedClassifierName,

                                                   outputJar );

                     if ( createSourcesJar )

                     {

                         projectHelper.attachArtifact( project, "jar", shadedClassifierName + "-sources", sourcesJar );

                     }

                 }

                 else if ( !renamed )

                 {

                     getLog().info( "Replacing original artifact with shaded artifact." );

                     File originalArtifact = project.getArtifact().getFile();

                     replaceFile( originalArtifact, outputJar );

                     if ( createSourcesJar )

                     {

                         File shadedSources = shadedSourcesArtifactFile();

                         replaceFile( shadedSources, sourcesJar );

                         projectHelper.attachArtifact( project, "jar", "sources", shadedSources );

                     }

                     if ( createDependencyReducedPom )

                     {

                         createDependencyReducedPom( artifactIds );

                     }

                 }

             }

         }

         catch ( Exception e )

         {

             throw new MojoExecutionException( "Error creating shaded jar: " + e.getMessage(), e );

         }

     }

     private void replaceFile( File oldFile, File newFile ) throws MojoExecutionException

     {

         getLog().info( "Replacing " + oldFile + " with " + newFile );

         File origFile = new File( outputDirectory, "original-" + oldFile.getName() );

         if ( oldFile.exists() && !oldFile.renameTo( origFile ) )

         {

             //try a gc to see if an unclosed stream needs garbage collecting

             System.gc();

             System.gc();

             if ( !oldFile.renameTo( origFile ) )

             {

                 // Still didn't work.   We'll do a copy

                 try

                 {

                     FileOutputStream fout = new FileOutputStream( origFile );

                     FileInputStream fin = new FileInputStream( oldFile );

                     try

                     {

                         IOUtil.copy( fin, fout );

                     }

                     finally

                     {

                         IOUtil.close( fin );

                         IOUtil.close( fout );

                     }

                 }

                 catch ( IOException ex )

                 {

                     //kind of ignorable here.   We're just trying to save the original

                     getLog().warn( ex );

                 }

             }

         }

         if ( !newFile.renameTo( oldFile ) )

         {

             //try a gc to see if an unclosed stream needs garbage collecting

             System.gc();

             System.gc();

             if ( !newFile.renameTo( oldFile ) )

             {

                 // Still didn't work.   We'll do a copy

                 try

                 {

                     FileOutputStream fout = new FileOutputStream( oldFile );

                     FileInputStream fin = new FileInputStream( newFile );

                     try

                     {

                         IOUtil.copy( fin, fout );

                     }

                     finally

                     {

                         IOUtil.close( fin );

                         IOUtil.close( fout );

                     }

                 }

                 catch ( IOException ex )

                 {

                     throw new MojoExecutionException( "Could not replace original artifact with shaded artifact!", ex );

                 }

             }

         }

     }

     private File resolveArtifactSources( Artifact artifact )

     {

         Artifact resolvedArtifact =

             artifactFactory.createArtifactWithClassifier( artifact.getGroupId(),

                                                           artifact.getArtifactId(),

                                                           artifact.getVersion(),

                                                           "java-source",

                                                           "sources" );

         try

         {

             artifactResolver.resolve( resolvedArtifact, remoteArtifactRepositories, localRepository );

         }

         catch ( ArtifactNotFoundException e )

         {

             // ignore, the jar has not been found

         }

         catch ( ArtifactResolutionException e )

         {

             getLog().warn( "Could not get sources for " + artifact );

         }

         if ( resolvedArtifact.isResolved() )

         {

             return resolvedArtifact.getFile();

         }

         return null;

     }

     private List getRelocators()

     {

         List relocators = new ArrayList();

         if ( relocations == null )

         {

             return relocators;

         }

         for ( int i = 0; i < relocations.length; i++ )

         {

             PackageRelocation r = relocations[i];

             relocators.add( new SimpleRelocator( r.getPattern(), r.getShadedPattern(), r.getExcludes() ) );

         }

         return relocators;

     }

     private List getResourceTransformers()

     {

         if ( transformers == null )

         {

             return Collections.EMPTY_LIST;

         }

         return Arrays.asList( transformers );

     }

     private List getFilters()

     {

         List filters = new ArrayList();

         if ( this.filters == null || this.filters.length <= 0 )

         {

             return filters;

         }

         Map artifacts = new HashMap();

         artifacts.put( project.getArtifact(), new ArtifactId( project.getArtifact() ) );

         for ( Iterator it = project.getArtifacts().iterator(); it.hasNext(); )

         {

             Artifact artifact = (Artifact) it.next();

             artifacts.put( artifact, new ArtifactId( artifact ) );

         }

         for ( int i = 0; i < this.filters.length; i++ )

         {

             ArchiveFilter filter = this.filters[i];

             ArtifactId pattern = new ArtifactId( filter.getArtifact() );

             Set jars = new HashSet();

             for ( Iterator it = artifacts.entrySet().iterator(); it.hasNext(); )

             {

                 Map.Entry entry = (Map.Entry) it.next();

                 if ( ( (ArtifactId) entry.getValue() ).matches( pattern ) )

                 {

                     jars.add( ( (Artifact) entry.getKey() ).getFile() );

                 }

             }

             if ( jars.isEmpty() )

             {

                 getLog().info( "No artifact matching filter " + filter.getArtifact() );

                 continue;

             }

             filters.add( new SimpleFilter( jars, filter.getIncludes(), filter.getExcludes() ) );

         }

         return filters;

     }

     private File shadedArtifactFileWithClassifier()

     {

         Artifact artifact = project.getArtifact();

         final String shadedName =

             shadedArtifactId + "-" + artifact.getVersion() + "-" + shadedClassifierName + "."

                 + artifact.getArtifactHandler().getExtension();

         return new File( outputDirectory, shadedName );

     }

     private File shadedSourceArtifactFileWithClassifier()

     {

         Artifact artifact = project.getArtifact();

         final String shadedName =

             shadedArtifactId + "-" + artifact.getVersion() + "-" + shadedClassifierName + "-sources."

                 + artifact.getArtifactHandler().getExtension();

         return new File( outputDirectory, shadedName );

     }

     private File shadedSourcesArtifactFile()

     {

         Artifact artifact = project.getArtifact();

         String shadedName;

         if ( project.getBuild().getFinalName() != null )

         {

             shadedName = project.getBuild().getFinalName() + "-sources." + artifact.getArtifactHandler().getExtension();

         }

         else

         {

             shadedName = shadedArtifactId + "-" + artifact.getVersion() + "-sources."

                 + artifact.getArtifactHandler().getExtension();

         }

         return new File( outputDirectory, shadedName );

     }

     // We need to find the direct dependencies that have been included in the uber JAR so that we can modify the

     // POM accordingly.

     private void createDependencyReducedPom( Set artifactsToRemove )

         throws IOException, DependencyTreeBuilderException, ProjectBuildingException

     {

         Model model = project.getOriginalModel();

         List dependencies = new ArrayList();

         boolean modified = false;

         List transitiveDeps = new ArrayList();

         for ( Iterator it = project.getArtifacts().iterator(); it.hasNext(); )

         {

             Artifact artifact = (Artifact) it.next();

             //promote

             Dependency dep = new Dependency();

             dep.setArtifactId( artifact.getArtifactId() );

             if ( artifact.hasClassifier() )

             {

                 dep.setClassifier( artifact.getClassifier() );

             }

             dep.setGroupId( artifact.getGroupId() );

             dep.setOptional( artifact.isOptional() );

             dep.setScope( artifact.getScope() );

             dep.setType( artifact.getType() );

             dep.setVersion( artifact.getVersion() );

             //we'll figure out the exclusions in a bit.

             transitiveDeps.add( dep );

         }

         List origDeps = project.getDependencies();

         if ( promoteTransitiveDependencies )

         {

             origDeps = transitiveDeps;

         }

         for ( Iterator i = origDeps.iterator(); i.hasNext(); )

         {

             Dependency d = (Dependency) i.next();

             dependencies.add( d );

             String id = getId( d );

             if ( artifactsToRemove.contains( id ) )

             {

                 modified = true;

                 if ( keepDependenciesWithProvidedScope )

                 {

                     d.setScope( "provided" );

                 }

                 else

                 {

                     dependencies.remove( d );

                 }

             }

         }

         // Check to see if we have a reduction and if so rewrite the POM.

         if ( modified )

         {

             while ( modified )

             {

                 model.setDependencies( dependencies );

                 /*

                  * NOTE: Be sure to create the POM in the original base directory to be able to resolve the relativePath

                  * to local parent POMs when invoking the project builder below.

                  */

                 File f = new File( project.getBasedir(), "dependency-reduced-pom.xml" );

                 if ( f.exists() )

                 {

                     f.delete();

                 }

                 Writer w = WriterFactory.newXmlWriter( f );

                 try

                 {

                     PomWriter.write( w, model, true );

                 }

                 finally

                 {

                     w.close();

                 }

                 MavenProject p2 = mavenProjectBuilder.build( f, localRepository, null );

                 modified = updateExcludesInDeps( p2, dependencies, transitiveDeps );

             }

             /*

              * NOTE: Although the dependency reduced POM in the project directory is temporary build output, we have to

              * use that for the file of the project instead of something in target to avoid messing up the base

              * directory of the project. We'll delete this file on exit to make sure it gets cleaned up but keep a copy

              * for inspection in the target directory as well.

              */

             File f = new File( project.getBasedir(), "dependency-reduced-pom.xml" );

             File f2 = new File( outputDirectory, "dependency-reduced-pom.xml" );

             FileUtils.copyFile( f, f2 );

             FileUtils.forceDeleteOnExit( f );

             project.setFile( f );

         }

     }

     private String getId( Artifact artifact )

     {

         return getId( artifact.getGroupId(), artifact.getArtifactId(), artifact.getType(), artifact.getClassifier() );

     }

     private String getId( Dependency dependency )

     {

         return getId( dependency.getGroupId(), dependency.getArtifactId(), dependency.getType(),

                       dependency.getClassifier() );

     }

     private String getId( String groupId, String artifactId, String type, String classifier )

     {

         return groupId + ":" + artifactId + ":" + type + ":" + ( ( classifier != null ) ? classifier : "" );

     }

     public boolean updateExcludesInDeps( MavenProject project,

                                          List dependencies,

                                          List transitiveDeps )

         throws DependencyTreeBuilderException

     {

         DependencyNode node = dependencyTreeBuilder.buildDependencyTree(

                                                   project,

                                                   localRepository,

                                                   artifactFactory,

                                                   artifactMetadataSource,

                                                   null,

                                                   artifactCollector );

         boolean modified = false;

         Iterator it = node.getChildren().listIterator();

         while ( it.hasNext() )

         {

             DependencyNode n2 = (DependencyNode) it.next();

             Iterator it2 = n2.getChildren().listIterator();

             while ( it2.hasNext() )

             {

                 DependencyNode n3 = (DependencyNode) it2.next();

                 //anything two levels deep that is marked "included"

                 //is stuff that was excluded by the original poms, make sure it

                 //remains excluded IF promoting transitives.

                 if ( n3.getState() == DependencyNode.INCLUDED )

                 {

                     //check if it really isn't in the list of original dependencies.  Maven

                     //prior to 2.0.8 may grab versions from transients instead of

                     //from the direct deps in which case they would be marked included

                     //instead of OMITTED_FOR_DUPLICATE

                     //also, if not promoting the transitives, level 2's would be included

                     boolean found = false;

                     for ( int x = 0; x < transitiveDeps.size(); x++ )

                     {

                         Dependency dep = (Dependency) transitiveDeps.get( x );

                         if ( dep.getArtifactId().equals( n3.getArtifact().getArtifactId() )

                             && dep.getGroupId().equals( n3.getArtifact().getGroupId() ) )

                         {

                             found = true;

                         }

                     }

                     if ( !found )

                     {

                         for ( int x = 0; x < dependencies.size(); x++ )

                         {

                             Dependency dep = (Dependency) dependencies.get( x );

                             if ( dep.getArtifactId().equals( n2.getArtifact().getArtifactId() )

                                 && dep.getGroupId().equals( n2.getArtifact().getGroupId() ) )

                             {

                                 Exclusion exclusion = new Exclusion();

                                 exclusion.setArtifactId( n3.getArtifact().getArtifactId() );

                                 exclusion.setGroupId( n3.getArtifact().getGroupId() );

                                 dep.addExclusion( exclusion );

                                 modified = true;

                                 break;

                             }

                         }

                     }

                 }

             }

         }

         return modified;

     }

 }