private static String findFreeFileName(String filename) {
    File f = new File(filename);
    if (! f.exists()) return filename;
    int dot = filename.lastIndexOf('.'); // we believe file has some ext. For instance,  ".wsdl"
    String name = filename.substring(0, dot);
    String ext = filename.substring(dot);
    int num = 0;
    do {
      f = new File(name + ++num + ext);
    } while (f.exists());
    return name + num + ext;
  }
private static String findFreeFileName(String filename)