s.checkAccept(p.getAddress().getHostAddress(), p.getPort());
s.checkAccept (p.getAddress().getHostName (), p.getPort ());  if (impl == null) throw new IOException ("Cannot initialize Socket implementation");  if (ch != null && !ch.isBlocking ()) throw new IllegalBlockingModeException ();
  public synchronized void receive(DatagramPacket p) throws IOException  {    SecurityManager s = System.getSecurityManager();    if (s != null)      s.checkAccept(p.getAddress().getHostAddress(), p.getPort());    impl.receive(p);  }