Multicasting using DatagramSocket by MultiThreading
//QuoteServerThread.java notepad
import java.io.*;
import java.net.*;
import java.util.*;
public class QuoteServerThread extends Thread {
protected DatagramSocket socket = null;
protected BufferedReader in = null;
protected boolean moreQuotes = true;
public QuoteServerThread() throws IOException {
this(“QuoteServerThread”);
}
public QuoteServerThread(String name) throws IOException {
super(name);
socket = new DatagramSocket(4445);
try {
in = new BufferedReader(new FileReader(“us.java”));
} catch (FileNotFoundException e) {
System.err.println(“Could not open quote file. Serving time instead.”);
}
}
public void run() {
while (moreQuotes) {
try {
byte[] buf = new byte[256];
// receive request
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
// figure out response
String dString = null;
if (in == null)
dString = new Date().toString();
else
dString = getNextQuote();
buf = dString.getBytes();
// send the response to the client at “address” and “port”
InetAddress address = packet.getAddress();
int port = packet.getPort();
packet = new DatagramPacket(buf, buf.length, address, port);
socket.send(packet);
} catch (IOException e) {
e.printStackTrace();
moreQuotes = false;
}
}
socket.close();
}
protected String getNextQuote() {
String returnValue = null;
try {
if ((returnValue = in.readLine()) == null) {
in.close();
moreQuotes = false;
returnValue = “No more quotes. Goodbye.”;
}
}
catch (IOException e) {
returnValue = “IOException occurred in server.”;
}
return returnValue;
}
}
2)
//MulticastServerThread.java notepad
import java.io.*;
import java.net.*;
import java.util.*;
public class MulticastServerThread extends QuoteServerThread {
private long FIVE_SECONDS = 5000;
public MulticastServerThread() throws IOException
{
super(“MulticastServerThread”);
}
public void run() {
while (moreQuotes) {
try {
byte[] buf = new byte[256];
// construct quote
String dString = null;
if (in == null)
dString = new Date().toString();
else
dString = getNextQuote();
buf = dString.getBytes();
// send it
InetAddress group = InetAddress.getByName(“230.0.0.1”);
DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 4446);
socket.send(packet);
// sleep for a while
try {
sleep((long)(Math.random() * FIVE_SECONDS));
} catch (InterruptedException e) { }
} catch (IOException e)
{
e.printStackTrace();
moreQuotes = false;
}
}
socket.close();
}
}
3)
//MulticastServer.java notepad
public class MulticastServer
{
public static void main(String[] args) throws java.io.IOException
{
new MulticastServerThread().start();
}
}
//MulticastClient.java notepad
import java.io.*;
import java.net.*;
import java.util.*;
public class MulticastClient {
public static void main(String[] args) throws IOException {
MulticastSocket socket = new MulticastSocket(4446);
InetAddress address = InetAddress.getByName(“230.0.0.1”);
socket.joinGroup(address);
DatagramPacket packet;
// get a few quotes
for (int i = 0; i < 5; i++) {
byte[] buf = new byte[256];
packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
String received = new String(packet.getData(), 0, packet.getLength());
System.out.println(“Quote of the Moment: ” + received);
}
socket.leaveGroup(address);
socket.close();
}
}
/* 1 cmd promp->javac QuoteServerThread.java
>javac MulticastServer.java
>java MulticastServer
==>make sure change file name present in code of QuoteServerThread, thats present in ur pc
2cmd promp->javac MulticastClient.java
>java MulticastClient
*/