protected void removeClassFile(IPath typePath, IContainer outputFolder) throws CoreException {
   if (typePath.lastSegment().indexOf('$') == -1) { // is not a nested type
     this.newState.removeQualifiedTypeName(typePath.toString());
     // add dependents even when the type thinks it does not exist to be on the safe side
     if (JavaBuilder.DEBUG) System.out.println("Found removed type " + typePath); // $NON-NLS-1$
     addDependentsOf(
         typePath,
         true); // when member types are removed, their enclosing type is structurally changed
   }
   IFile classFile =
       outputFolder.getFile(typePath.addFileExtension(SuffixConstants.EXTENSION_class));
   if (classFile.exists()) {
     if (JavaBuilder.DEBUG)
       System.out.println("Deleting class file of removed type " + typePath); // $NON-NLS-1$
     classFile.delete(IResource.FORCE, null);
   }
 }
  protected void cleanOutputFolders(boolean copyBack) throws CoreException {
    boolean deleteAll =
        JavaCore.CLEAN.equals(
            this.javaBuilder.javaProject.getOption(
                JavaCore.CORE_JAVA_BUILD_CLEAN_OUTPUT_FOLDER, true));
    if (deleteAll) {
      if (this.javaBuilder.participants != null)
        for (int i = 0, l = this.javaBuilder.participants.length; i < l; i++)
          this.javaBuilder.participants[i].cleanStarting(this.javaBuilder.javaProject);

      ArrayList visited = new ArrayList(this.sourceLocations.length);
      for (int i = 0, l = this.sourceLocations.length; i < l; i++) {
        this.notifier.subTask(
            Messages.bind(
                Messages.build_cleaningOutput, this.javaBuilder.currentProject.getName()));
        ClasspathMultiDirectory sourceLocation = this.sourceLocations[i];
        if (sourceLocation.hasIndependentOutputFolder) {
          IContainer outputFolder = sourceLocation.binaryFolder;
          if (!visited.contains(outputFolder)) {
            visited.add(outputFolder);
            IResource[] members = outputFolder.members();
            for (int j = 0, m = members.length; j < m; j++) {
              IResource member = members[j];
              if (!member.isDerived()) {
                member.accept(
                    new IResourceVisitor() {
                      public boolean visit(IResource resource) throws CoreException {
                        resource.setDerived(true, null);
                        return resource.getType() != IResource.FILE;
                      }
                    });
              }
              member.delete(IResource.FORCE, null);
            }
          }
          this.notifier.checkCancel();
          if (copyBack) copyExtraResourcesBack(sourceLocation, true);
        } else {
          boolean isOutputFolder = sourceLocation.sourceFolder.equals(sourceLocation.binaryFolder);
          final char[][] exclusionPatterns =
              isOutputFolder
                  ? sourceLocation.exclusionPatterns
                  : null; // ignore exclusionPatterns if output folder == another source folder...
                          // not this one
          final char[][] inclusionPatterns =
              isOutputFolder
                  ? sourceLocation.inclusionPatterns
                  : null; // ignore inclusionPatterns if output folder == another source folder...
                          // not this one
          sourceLocation.binaryFolder.accept(
              new IResourceProxyVisitor() {
                public boolean visit(IResourceProxy proxy) throws CoreException {
                  if (proxy.getType() == IResource.FILE) {
                    if (org.eclipse.jdt.internal.compiler.util.Util.isClassFileName(
                        proxy.getName())) {
                      IResource resource = proxy.requestResource();
                      if (exclusionPatterns != null || inclusionPatterns != null)
                        if (Util.isExcluded(
                            resource.getFullPath(), inclusionPatterns, exclusionPatterns, false))
                          return false;
                      if (!resource.isDerived()) resource.setDerived(true, null);
                      resource.delete(IResource.FORCE, null);
                    }
                    return false;
                  }
                  if (exclusionPatterns != null
                      && inclusionPatterns
                          == null) // must walk children if inclusionPatterns != null
                  if (Util.isExcluded(proxy.requestFullPath(), null, exclusionPatterns, true))
                      return false;
                  BatchImageBuilder.this.notifier.checkCancel();
                  return true;
                }
              },
              IResource.NONE);
          this.notifier.checkCancel();
        }
        this.notifier.checkCancel();
      }
    } else if (copyBack) {
      for (int i = 0, l = this.sourceLocations.length; i < l; i++) {
        ClasspathMultiDirectory sourceLocation = this.sourceLocations[i];
        if (sourceLocation.hasIndependentOutputFolder)
          copyExtraResourcesBack(sourceLocation, false);
        this.notifier.checkCancel();
      }
    }
    // GROOVY start
    LanguageSupportFactory.getEventHandler()
        .handle(this.javaBuilder.javaProject, "cleanOutputFolders");
    // GROOVY end
  }