This document discusses building a multicast network using UDP. It explains that UDP is simpler and faster than TCP. It then shows code for a basic UDP client-server program where the client sends a message to the server. The server receives the message, converts it to uppercase, and sends it back to the client. The client then prints the modified message received from the server.

1. MULTICAST NETWORK
Mobile Programming

2. LAST WEEK

4. TODAY
It’s all about UDP

5. USER DATAGRAM PROTOCOL

6. USER DATAGRAM PROTOCOL

8. UDPVSTCP
UDP is simple and faster
compared toTCP

9. NOW LET’S BROADCAST
SOMETHING!

10. WHAT WE WILL BUILD

11. WHAT WE WILL BUILD
Hello
Client
Server
HELLO

12. 1 import java.io.*;
2 import java.net.*;
3
4 class UDPServer {
5 public static void main(String args[]) throws Exception {
6 DatagramSocket serverSocket = new DatagramSocket(9876);
7 byte[] receiveData = new byte[1024];
8 byte[] sendData = new byte[1024];
9
10 while(true) {
11 DatagramPacket receivePacket = new DatagramPacket(receiveData,
12 receiveData.length);
13 serverSocket.receive(receivePacket);
14 String sentence = new String(receivePacket.getData());
15 System.out.println("RECEIVED: " + sentence);
16 InetAddress IPAddress = receivePacket.getAddress();
17 int port = receivePacket.getPort();
18 String capitalizedSentence = sentence.toUpperCase();
19 sendData = capitalizedSentence.getBytes();
20 DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.
21 length, IPAddress, port);
22 serverSocket.send(sendPacket);
23 }
24 }
25 }

13. 1 import java.io.*;
2 import java.net.*;
3
4 class UDPClient {
5 public static void main(String args[]) throws Exception {
6 BufferedReader inFromUser = new BufferedReader(new
InputStreamReader(
7 System.in));
8 DatagramSocket clientSocket = new DatagramSocket();
9 InetAddress IPAddress =InetAddress.getByName("localhost");
10 byte[] sendData = new byte[1024];
11 byte[] receiveData = new byte[1024];
12 String sentence = inFromUser.readLine();
13 sendData = sentence.getBytes();
14 DatagramPacket sendPacket = new DatagramPacket(sendData,
sendData.length,
15 IPAddress, 9876);
16 clientSocket.send(sendPacket);
17
18
19 DatagramPacket receivePacket = new DatagramPacket(receiveData,
20 receiveData.length);
21 clientSocket.receive(receivePacket);
22 String modifiedSentence = new String(receivePacket.getData());
23 System.out.println("FROM SERVER: " + modifiedSentence);
24 clientSocket.close();
25 }
26 }

14. YOURTURN!

15. YOURTURN!
Besok
Client
Server
16 Maret 2016

16. GROUP ASSIGNMENT