Name: yyT116575 Date: 02/05/2001


java version "1.3.0"
Java(TM) 2 Runtime Environment. Standard Edition (build 1.3.0-c)
Java HotSpot(TM) Client VM (build 1.3.0-C.mixed mode)


1. byte[] getData()in java.net.DatagramPacket returns the current packet data
along with the old packet information.
2. The sample Server and Client programs are,

//Server Program starts here

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

class TestServer {
  public static void main(String args[]) throws Exception {
    DatagramSocket ds = new DatagramSocket(6000);
    byte b[] = new byte[100];
    DatagramPacket dp = new DatagramPacket(b,b.length);
    while(true) {
      System.out.println("Waiting...");
      ds.receive(dp);
      String reply = "Hello Mr/Ms."+new String(dp.getData());
      ds.send(new DatagramPacket(reply.getBytes(),reply.length(),dp.getAddress(),dp.getPort()));
    }
  }
}

//Server Program ends here


//Client Program starts here

import java.net.*;

class TestClient {
  public static void main(String args[]) throws Exception {
    String msg = args[0];
    DatagramSocket ds = new DatagramSocket();
    byte b[] = new byte[100];
    DatagramPacket dp = new DatagramPacket(b,b.length);
    ds.send(new DatagramPacket(msg.getBytes(),msg.length(),InetAddress.getByName("LocalHost"),6000));
    ds.receive(dp);
    System.out.println("Reply : "+new String(dp.getData()));
  }
}

//Client Program ends here

The output in the client side will be as
----------------------------------------
(a) For the first time,

>java TestClient HelloWorld <Enter>
Reply : Hello Mr/Ms.HelloWorld

(b) For the second time,

>java TestClient Java <Enter>
Reply : Hello Mr/Ms.JavaoWorld
------//The extra old data is also returned by the getData() method of DatagramPacket.
(Review ID: 116279)
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