public class AutoTestBuilder extends IncrementalProjectBuilder {
  private static boolean enabled= true;
  private static boolean trace= false;

  public AutoTestBuilder() {
  }

  protected IProject[] build(int kind, Map args,
     IProgressMonitor pm) throws CoreException {
    if (hasBuildErrors() || !AutoTestBuilder.enabled)
     return null;
    IJavaProject javaProject= JavaCore.create(getProject());
    IType[] types= new TestSearcher().findAll(javaProject, pm);
    types= exclude(types);
    if (trace)
     printTestTypes(types);
    JUnitPlugin.getPlugin().run(types, javaProject);
    return null;
  }

  public static void setEnabled(boolean isEnabled) {
    AutoTestBuilder.enabled= isEnabled;
  }

  private boolean hasBuildErrors() throws CoreException {
    IMarker[] markers= getProject().findMarkers(
     IJavaModelMarker.JAVA_MODEL_PROBLEM_MARKER, false,
    IResource.DEPTH_INFINITE);
    for (int i= 0; i < markers.length; i++) {
      IMarker marker= markers[i];
      if (marker.getAttribute(
         IMarker.SEVERITY, 0) == IMarker.SEVERITY_ERROR)
       return true;
    }
    return false;
  }

  static {
    String value= Platform.getDebugOption(
      "org.eclipse.contribution.junit/trace/testfinding");
    if (value != null && value.equalsIgnoreCase("true"))
      trace= true;
  }

  private static void printTestTypes(IType[] tests) {
    System.out.println("Auto Test: "); //$NON-NLS-1$
    for (int i= 0; i < tests.length; i++) {
      System.out.println("	"+tests[i].getFullyQualifiedName());
    }
  }

 private IType[] exclude(IType[] types) {
    try {
      Set exclusions= readExclusions(getProject().getFile(
        new Path("test.exclusions")));
      List result= new ArrayList(types.length);
      for (int i= 0; i < types.length; i++) {
        IType type= types[i];
        String typeName= type.getFullyQualifiedName();
        if (!exclusions.contains(typeName))
          result.add(type);
        return (IType[])(result.toArray(
          new IType[result.size()]));
      }
    } catch (Exception e) {
      // fall through
    }
    return types;
  }

 private Set readExclusions(IFile file)
     throws IOException, CoreException {
    Set result= new HashSet();
    BufferedReader br= new BufferedReader(
      new InputStreamReader(file.getContents()));
    try {
      String line;
      while ((line= br.readLine()) != null) {
        line= line.trim();
        if (line.length() > 0)
          result.add(line);
      }
    } finally {
      br.close();
    }
    return result;
  }
}