package org.codehaus.plexus.maven.plugin;
   
   /*
    * Copyright (c) 2004-2006, Codehaus.org
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
    * associated documentation files (the "Software"), to deal in the Software without restriction,
    * including without limitation the rights to use, copy, modify, merge, publish, distribute,
    * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all copies or
   * substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
   * NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
   * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  import java.io.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.annotations.Component;
  import org.apache.maven.plugins.annotations.LifecyclePhase;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.codehaus.plexus.metadata.merge.Merger;
  
  /**
   * Merges a set of Plexus descriptors into one descriptor file.
   *
   * @author Jason van Zyl
   * @author Trygve Laugstøl
   */
  @Mojo(name = "merge-metadata", defaultPhase = LifecyclePhase.PROCESS_CLASSES)
  public class PlexusMergeMojo extends AbstractMojo {
      /**
       * The destination for the merged descriptor.
       */
      @Parameter(defaultValue = "${project.build.outputDirectory}/META-INF/plexus/components.xml", required = true)
      private File output;
  
      /**
       * The paths of the input descriptors to merge.
       */
      @Parameter
      private File[] descriptors;
  
      @Component(hint = "componentsXml")
      private Merger merger;
  
      public void execute() throws MojoExecutionException {
          List<File> files = new ArrayList<File>();
  
          if (descriptors != null) {
              files.addAll(Arrays.asList(descriptors));
          }
  
          if (files.isEmpty()) {
              return;
          }
  
          try {
              merger.mergeDescriptors(output, files);
          } catch (IOException e) {
              throw new MojoExecutionException("Error while executing component descriptor creator.", e);
          }
      }
  }