DatagramServerClient

package pack;

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

public class DatagramClient {
public static void main(String[] args) throws IOException {
// Adresa IP si portul la care ruleaza serverul
InetAddress adresa = InetAddress.getByName(" 192.168.198.1 ");
int port = 8200;
DatagramSocket socket = null;
DatagramPacket packet = null;
byte buf[];
try {
// Construim un socket pentru comunicare
socket = new DatagramSocket();
// Construim si trimitem pachetul cu cererea catre server
buf = " Duke ".getBytes();

packet = new DatagramPacket(buf, buf.length, adresa, port);
socket.send(packet);
// Asteaptam pachetul cu raspunsul de la server
buf = new byte[256];
packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
// Afisam raspunsul (" Hello Duke !")
System.out.println(new String(packet.getData()));
} finally {
if (socket != null)
socket.close();
}
}
}

package pack;

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

public class DatagramServer {
public static final int PORT = 8200;
private DatagramSocket socket = null;
DatagramPacket cerere, raspuns = null;

public void start() throws IOException {
socket = new DatagramSocket(PORT);
try {
while (true) {
// Declaram pachetul in care va fi receptionat cererea
byte[] buf = new byte[256];
cerere = new DatagramPacket(buf, buf.length);
System.out.println(" Asteptam un pachet ... ");
socket.receive(cerere);
// Aflam adresa si portul de la care vine cererea
InetAddress adresa = cerere.getAddress();
int port = cerere.getPort();
// Construim raspunsul

String mesaj = " Hello " + new String(cerere.getData());
buf = mesaj.getBytes();
// Trimitem un pachet cu raspunsul catre client
raspuns = new DatagramPacket(buf, buf.length, adresa, port);
socket.send(raspuns);
}
} finally {
if (socket != null)
socket.close();
}
}

public static void main(String[] args) throws IOException {
new DatagramServer().start();
}
}