public boolean isReferenceFromEar(IClasspathEntryDescriptor descriptor) {

      IClasspathEntry entry = descriptor.getClasspathEntry();
      String scope = descriptor.getScope();

      // these dependencies aren't added to the manifest cp
      // retain optional dependencies here, they might be used just to express the
      // dependency to be used in the manifest
      if (Artifact.SCOPE_PROVIDED.equals(scope)
          || Artifact.SCOPE_TEST.equals(scope)
          || Artifact.SCOPE_SYSTEM.equals(scope)) {
        return false;
      }

      // calculate in regard to includes/excludes whether this jar is
      // to be packaged into  WEB-INF/lib
      String jarFileName = "WEB-INF/lib/" + entry.getPath().lastSegment();
      return isExcludedFromWebInfLib(jarFileName);
    }
  public void configureClasspath(
      IProject project,
      MavenProject mavenProject,
      IClasspathDescriptor classpath,
      IProgressMonitor monitor)
      throws CoreException {

    // Improve skinny war support by generating the manifest classpath
    // similar to mvn eclipse:eclipse
    // http://maven.apache.org/plugins/maven-war-plugin/examples/skinny-wars.html
    WarPluginConfiguration config = new WarPluginConfiguration(mavenProject, project);
    WarPackagingOptions opts = new WarPackagingOptions(config);

    StringBuilder manifestCp = new StringBuilder();

    /*
     * Need to take care of three separate cases
     *
     * 1. remove any project dependencies (they are represented as J2EE module dependencies)
     * 2. add non-dependency attribute for entries originated by artifacts with
     *    runtime, system, test scopes or optional dependencies (not sure about the last one)
     * 3. make sure all dependency JAR files have unique file names, i.e. artifactId/version collisions
     */

    Set<String> dups = new LinkedHashSet<String>();
    Set<String> names = new HashSet<String>();

    // first pass removes projects, adds non-dependency attribute and collects colliding filenames
    Iterator<IClasspathEntryDescriptor> iter = classpath.getEntryDescriptors().iterator();
    while (iter.hasNext()) {
      IClasspathEntryDescriptor descriptor = iter.next();
      IClasspathEntry entry = descriptor.getClasspathEntry();
      String scope = descriptor.getScope();
      String key =
          ArtifactUtils.versionlessKey(descriptor.getGroupId(), descriptor.getArtifactId());
      Artifact artifact = mavenProject.getArtifactMap().get(key);
      String extension = artifact.getArtifactHandler().getExtension();

      if (IClasspathEntry.CPE_PROJECT == entry.getEntryKind()
          && Artifact.SCOPE_COMPILE.equals(scope)) {
        // get deployed name for project dependencies
        // TODO can this be done somehow more elegantly?
        IProject p =
            (IProject) ResourcesPlugin.getWorkspace().getRoot().findMember(entry.getPath());

        IVirtualComponent component = ComponentCore.createComponent(p);

        boolean usedInEar = opts.isReferenceFromEar(component, extension);
        if (opts.isSkinnyWar() && usedInEar) {
          if (manifestCp.length() > 0) {
            manifestCp.append(" ");
          }
          // MNGECLIPSE-2393 prepend ManifestClasspath prefix
          if (config.getManifestClasspathPrefix() != null
              && !JEEPackaging.isJEEPackaging(artifact.getType())) {
            manifestCp.append(config.getManifestClasspathPrefix());
          }

          manifestCp.append(component.getDeployedName()).append(".").append(extension);
        }

        if (!descriptor.isOptionalDependency() || usedInEar) {
          // remove mandatory project dependency from classpath
          iter.remove();
          continue;
        } // else : optional dependency not used in ear -> need to trick ClasspathAttribute with
          // NONDEPENDENCY_ATTRIBUTE
      }

      if (opts.isSkinnyWar() && opts.isReferenceFromEar(descriptor)) {

        if (manifestCp.length() > 0) {
          manifestCp.append(" ");
        }
        if (config.getManifestClasspathPrefix() != null
            && !JEEPackaging.isJEEPackaging(artifact.getType())) {
          manifestCp.append(config.getManifestClasspathPrefix());
        }
        manifestCp.append(entry.getPath().lastSegment());

        // ear references aren't kept in the Maven Dependencies
        iter.remove();
        continue;
      }

      // add non-dependency attribute
      // Check the scope & set WTP non-dependency as appropriate
      // Optional artifact shouldn't be deployed
      if (Artifact.SCOPE_PROVIDED.equals(scope)
          || Artifact.SCOPE_TEST.equals(scope)
          || Artifact.SCOPE_SYSTEM.equals(scope)
          || descriptor.isOptionalDependency()) {
        descriptor.addClasspathAttribute(NONDEPENDENCY_ATTRIBUTE);
      }

      // collect duplicate file names
      if (!names.add(entry.getPath().lastSegment())) {
        dups.add(entry.getPath().lastSegment());
      }
    }

    String targetDir = mavenProject.getBuild().getDirectory();

    // second pass disambiguates colliding entry file names
    iter = classpath.getEntryDescriptors().iterator();
    while (iter.hasNext()) {
      IClasspathEntryDescriptor descriptor = iter.next();
      IClasspathEntry entry = descriptor.getClasspathEntry();

      if (dups.contains(entry.getPath().lastSegment())) {
        File src = new File(entry.getPath().toOSString());
        String groupId = descriptor.getGroupId();
        File dst = new File(targetDir, groupId + "-" + entry.getPath().lastSegment());
        try {
          if (src.canRead()) {
            if (isDifferent(src, dst)) { // uses lastModified
              FileUtils.copyFile(src, dst);
              dst.setLastModified(src.lastModified());
            }
            descriptor.setClasspathEntry(
                JavaCore.newLibraryEntry(
                    Path.fromOSString(dst.getCanonicalPath()), //
                    entry.getSourceAttachmentPath(), //
                    entry.getSourceAttachmentRootPath(), //
                    entry.getAccessRules(), //
                    entry.getExtraAttributes(), //
                    entry.isExported()));
          }
        } catch (IOException ex) {
          MavenLogger.log("File copy failed", ex);
        }
      }
    }

    if (opts.isSkinnyWar()) {

      // writing the manifest only works when the project has been properly created
      // placing this check on the top of the method broke 2 other tests
      // thats why its placed here now.
      if (ComponentCore.createComponent(project) == null) {
        return;
      }

      // write manifest, using internal API - seems ok for 3.4/3.5, though
      ArchiveManifest mf = J2EEProjectUtilities.readManifest(project);
      if (mf == null) {
        mf = new ArchiveManifestImpl();
      }
      mf.addVersionIfNecessary();
      mf.setClassPath(manifestCp.toString());

      try {
        J2EEProjectUtilities.writeManifest(project, mf);
      } catch (Exception ex) {
        MavenLogger.log("Could not write web module manifest file", ex);
      }
    }
  }