// This example is from the book _Java in a Nutshell_ by David Flanagan.
// Written by David Flanagan.  Copyright (c) 1996 O'Reilly & Associates.
// You may study, use, modify, and distribute this example for any purpose.
// This example is provided WITHOUT WARRANTY either expressed or implied.

import java.io.*;
import java.net.*;

// This program waits to receive datagrams sent to port 6010.  
// When it receives one, it displays the sending host and port, 
// and prints the contents of the datagram as a string.
public class UDPReceive {
    static final int port = 6010;
    public static void main(String args[]) throws Exception
    {
        byte[] buffer = new byte[1024];
        String s;
        // Create a socket to listen on the port.
        DatagramSocket socket = new DatagramSocket(port);
        
        for(;;) {
            // Create a packet with an empty buffer to receive data
	    // Bug workaround: create a new packet each time through the loop.
            // If we create the packet outside of this loop, then it seems to
            // loose track of its buffer size, and incoming packets are 
            // truncated.
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
            // Wait to receive a datagram
            socket.receive(packet);
            // Convert the contents to a string
            s = new String(buffer, 0, 0, packet.getLength());
            // And display them
            System.out.println("UDPReceive: received from " + 
                       packet.getAddress().getHostName() + ":" +
                       packet.getPort() + ": " + s);
        }
    }
}