Multicast chat program

Chat Client Full Code

public class MulticastChatClient extends MulticastChatClientGUI

{

public ButtonHandler bHandler;

DatagramSocket socket;

String ipAddress;

String userName;

String passWord;

String msgToBuf;

String logMsg= "";

String checkBye;

Boolean authenticatedUser;

String deNullString (String s)

{

//Function to get rid of garbage at the end of the buffer prior to

//displaying it on the screen and saving to file.

String result = "";

int i = 0;

while (s.charAt(i) != '\0')

{

result = result + s.charAt(i);

i ++;

}

return result;

}

public MulticastChatClient (String title)

{

super (title);

bHandler = new ButtonHandler();

sendButton.addActionListener( bHandler );

try

{

socket = new DatagramSocket ();

}

catch (IOException e)

{

}

}

private class ButtonHandler implements ActionListener

{

public void actionPerformed (ActionEvent event) //throws IOException

{

// Get a datagram socket

try

{

byte[] buf = new byte[128];

InetAddress address = InetAddress.getByName (ipAddress);

//Put username before the message the user sends

msgToBuf=userName + " Says >> ";

//Populate buffer with text in the txArea

msgToBuf=msgToBuf + txArea.getText();

buf = msgToBuf.getBytes();

//Open up port 4448 and prepare to send the packet

DatagramPacket packet = new DatagramPacket (buf, buf.length, address, 4448);

System.out.println ("About to send packet");

//Send the packet to the server

socket.send(packet);

System.out.println ("Packet sent");

}

catch (IOException e)

{

//Error handling

System.err.println("Couldn't get I/O for the connection to the server");

System.exit(1);

}

}

}

public void run () throws IOException

{

//Welcome user, ask for their name

userName = JOptionPane.showInputDialog(null,"Please enter your name...",

"Welcome To Chat V1.0",JOptionPane.QUESTION_MESSAGE);

//Password verification

//Promt user to enter password

passWord = JOptionPane.showInputDialog(null,"Please enter password...",

"User Authentication",JOptionPane.QUESTION_MESSAGE);

if(passWord.equals ("letmein"))

{

//Correct password

authenticatedUser = true;

}

else

{

//Wrong password

authenticatedUser = false;

//Inform the user and close the application

JOptionPane.showMessageDialog(null, "Wrong Password, Chat program ended",

"Authenticaion Failure",JOptionPane.INFORMATION_MESSAGE);

System.exit(1);

}

//User To Enter IP Address

ipAddress = JOptionPane.showInputDialog(null, "Thanks " +userName+ "... Please Enter Server IP",

"Connection Details",JOptionPane.QUESTION_MESSAGE);

// set up connection to multicast server

if (userName.startsWith ("Steve") || userName.startsWith ("David"))

{

MulticastSocket socket = new MulticastSocket (4447);

InetAddress address = InetAddress.getByName ("233.0.0.13");

socket.joinGroup (address);

}

else

{

MulticastSocket socket = new MulticastSocket (4449);

InetAddress address = InetAddress.getByName ("232.0.0.13");

socket.joinGroup (address);

}

while (true)

{

// send request

byte[] buf = new byte[128];

DatagramPacket packet = new DatagramPacket (buf, buf.length);

socket.receive (packet);

System.out.println ("Received packet");

// display response

String received = new String (packet.getData());

System.out.println ("Remote packet: " + received);

logMsg = logMsg + "\n" + deNullString (received);

checkBye = txArea.getText();

if (checkBye.equals ("Bye"))

{

try

{

//Create log file ClientMsg.log, outFile is used to operate on it

BufferedWriter outFile = new BufferedWriter (new FileWriter ("ClientMsg.log"));

outFile.write (logMsg);

outFile.close();

}

catch (IOException i){}

//Tell user the program is about to close

JOptionPane.showMessageDialog(null, "You terminated connection, Chat program ended",

"Session Info",JOptionPane.INFORMATION_MESSAGE);

System.exit(0);

}

rxArea.setText (rxArea.getText() + "\n" + deNullString (received));

}

}

Chat Server Full Code:

public class MulticastChatServer

{

public static void main(String[] args) throws java.io.IOException

{

//Open up socket and listen on port 4448

DatagramSocket socket = new DatagramSocket (4448);

DatagramPacket packet;

//Variable to hold all messages

String logMsg="";

System.out.println ("Starting Multicast Chat Server");

//Loop forever

while (true)

{

try

{

//Setup a 128 Byte array

byte[] buf = new byte[128];

// receive packet

packet = new DatagramPacket (buf, buf.length);

socket.receive (packet);

InetAddress address = packet.getAddress ();

int port = packet.getPort ();

//Convert buffer into a string

String received = new String (packet.getData());

//Add the IP address to the packet received

//received = "(" + address + ") " + received;

//Print received message on the console

System.out.println (received);

//Put the data into the buffer

buf = received.getBytes ();

//Write message to the message log variable

logMsg = logMsg + "\n" + received;

try

{

//Create log file ClientMsg.log, outFile is used to operate on it

BufferedWriter outFile = new BufferedWriter (new FileWriter ("ServerMsg.log"));

//Write the contents of logMsg to the file

outFile.write (logMsg);

//Close the file

outFile.close();

}

catch (IOException i){}

// multicast it

if (received.startsWith ("Steve") || received.startsWith ("David"))

{

System.out.println ("met");

InetAddress group = InetAddress.getByName ("233.0.0.13");

packet = new DatagramPacket (buf, buf.length, group, 4447);

socket.send (packet);

System.out.println ("met2");

}

else

{

InetAddress group = InetAddress.getByName ("232.0.0.13");

packet = new DatagramPacket (buf, buf.length, group, 4449);

socket.send (packet);

}

}

catch (IOException e)

{

e.printStackTrace();

}

}

}

}

steveoelliotta at 2007-7-8 23:36:01 >

Steve

You're redeclaring 'socket' inside those if/else scopes, and so those blocks only operate on that local 'socket', which then disappears at the closing }. Just change this:

MulticastSocket socket = new MulticastSocket(4449); // or 4447 or whatever

to:

socket = new MulticastSocket(4449); // or 4447 or whatever

both times.

ejpa at 2007-7-8 23:36:01 >