UDP0.java Source code

Introduction

Here is the source code for UDP0.java

Source

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UDP0 {
    // command line arguments:
    // r -- read an incoming packet
    // w hostname word -- write word to hostname
    public static void main(String[] args) throws Exception {
        byte[] ary = new byte[128];
        DatagramPacket pack = new DatagramPacket(ary, 128);
        if (args[0].charAt(0) == 'r') {
            // read
            DatagramSocket sock = new DatagramSocket(1111);
            sock.receive(pack);
            String word = new String(pack.getData());
            System.out.println("From: " + pack.getAddress() + " Port: " + pack.getPort());
            System.out.println(word);
            sock.close();
        } else { // write
            DatagramSocket sock = new DatagramSocket();
            pack.setAddress(InetAddress.getByName(args[1]));
            pack.setData(args[2].getBytes());
            pack.setPort(1111);
            sock.send(pack);
            sock.close();
        }
    }
}