this.hostname = addr.getHostName();
  public InetSocketAddress(InetAddress addr, int port)    throws IllegalArgumentException  {    if (port < 0 || port > 65535)      throw new IllegalArgumentException("Bad port number: " + port);    if (addr == null)      addr = InetAddress.ANY_IF;      this.addr = addr;    this.port = port;    this.hostname = addr.getHostName();  }