package com.ronsoft.books.nio.channels; import java.nio.ByteBuffer; import java.nio.channels.DatagramChannel; import java.net.SocketAddress; import java.net.InetSocketAddress; import java.net.InetAddress; /** * Tickle DatagramChannel send() bug. Attempting to send a datagram * to a SocketAddress which does not resolve to a real address causes * the JVM to crash (tested on linux and solaris 8). * * @author Ron Hitchens (ron@ronsoft.com) * @version $Id: DGKaboom.java,v 1.2 2002/04/25 23:26:55 ron Exp $ */ public class DGKaboom { // first arg, if present, is host name to send to. // second arg, if present, is port number to send to public static void main (String [] argv) throws Exception { String host = "foo.bar"; int port = 37; if (argv.length > 0) { host = argv [0]; } if (argv.length > 1) { port = Integer.parseInt (argv [1]); } DatagramChannel dc = DatagramChannel.open(); ByteBuffer bb = ByteBuffer.allocate (4); InetSocketAddress sa = new InetSocketAddress (host, port); InetAddress inetaddr = sa.getAddress(); if (inetaddr == null) { System.out.println ("No address resolved for " + host); } else { System.out.println ("Address of " + host + " is " + inetaddr); } System.out.println ("Attempting send to " + sa); // if sa does not resolve to an address, kablooey dc.send (bb, sa); System.out.println ("Sent OK"); dc.close(); } }