private void walkDir(File dir, FileFilter classesFilter, FileFilter dirFilter) {
File[] dirs = dir.listFiles( dirFilter );
if (dirs != null) {
for (File dir1 : dirs) {
walkDir(dir1, classesFilter, dirFilter);
}
}
File[] files = dir.listFiles( classesFilter );
if (files != null) {
Collections.addAll( this.sourceSet, files );
}
}