import java.net.*;import java.io.*;/** * This example illustrates the basic method calls for connectionless * datagram socket. * @author M. L. Liu */public class Example1Receiver {// An application which receives a message using connectionless// datagram socket.// A command line argument is expected, in order: // <port number of the receiver's socket>// Note: the same port number should be specified in the// command-line arguments for the sender. public static void main(String[] args) { if (args.length != 1) System.out.println ("This program requires a command line argument."); else { int port = Integer.parseInt(args[0]); final int MAX_LEN = 10; // This is the assumed maximum byte length of the // datagram to be received. try { DatagramSocket mySocket = new DatagramSocket(port); // instantiates a datagram socket for receiving the data byte[ ] buffer = new byte[MAX_LEN]; DatagramPacket datagram = new DatagramPacket(buffer, MAX_LEN); mySocket.receive(datagram); System.out.println("Messages received:"); String message = new String(buffer); System.out.println(message); while (!message.equals("bye")) { buffer = new byte[MAX_LEN]; datagram = new DatagramPacket(buffer, MAX_LEN); mySocket.receive(datagram); message = new String(buffer); System.out.println("\"" + message + "\""); System.out.println(message.equals("bye")); } mySocket.close( ); } // end try catch (Exception ex) { ex.printStackTrace( ); } } // end else } // end main} // end class