private static String readClassName(DataInput di) throws IOException {
  int len=di.readInt();
  byte[] bytes=new byte[len];
  di.readFully(bytes);
  return new String(bytes);
}

private static String readClassName ( DataInput di ) throws IOException { int len = di . readInt ( ) ; byte [ ] bytes = new byte [ len ] ; di . readFully ( bytes ) ; return new String ( bytes ) ; }
reads a class name from the given input stream .
