Thread: Muliple Client Server chat application..how to send message from server..

hi i am new to java I wrote following code..all clients to server communicating well..when i want to send message from Server to connected clients client dont receive it..how to resolve this.code displayed below
Server:
import java.io.*;
import java.net.*;
class MulServerThread
{
//declaration
private static ServerSocket serverSocket = null;
private static Socket socket = null;
private static final int maxclients = 5;
//array of thread creation
private static final clientThread[] threads = new clientThread[maxclients];//accepts only 5 clients

public static void main(String args[])
{
try
{
//start of main method
int port = 1774;
serverSocket = new ServerSocket(port);
System.out.println("waiting for client......");
while(true)
{
socket = serverSocket.accept();//accept the
int i = 0;
//pass into new client thread
for(i = 0;i < maxclients;i++)
{
if(threads[i]==null)
{
(threads[i] = new clientThread(socket,threads)).start();//start array of thread
break;
}
}
if(i == maxclients)
{
PrintStream out = new PrintStream(socket.getOutputStream());//send data to the client
out.println("Server busy........please try after some time.");
//close the connection
out.close();
socket.close();
}
}
}
catch(IOException e)
{
System.out.println("IOException"+e);
}
}
}
class clientThread extends Thread
{
private int maxclients;
private DataInputStream is = null;//receive response from client
private PrintStream out = null;//send the data to client
private Socket socket = null;
private final clientThread[] threads;
public clientThread(Socket socket,clientThread[] threads)
{
this.socket = socket;
this.threads = threads;
maxclients = threads.length;
}
public void run()
{
//start of run method
int maxclients = this.maxclients;
clientThread[] threads = this.threads;
try
{
//create input output stream for client
is=new DataInputStream(socket.getInputStream());
//send data to the client
out = new PrintStream(socket.getOutputStream());
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String send;

out.println("Hai...Enter your name.");
String name,message;
name = is.readLine();
out.println("Hello "+name+" to our chat room.\tTo leave enter close");//display the message to available client thread
for(int i = 0;i < maxclients;i++)
{
if(threads[i] != null)
{
threads[i].out.println("New user "+name+" entered in to the chat room");
}
}
System.out.println("New user "+name+" entered in to the chat room\n");//print in a console
/*for(int i=0;i<maxclients;i++)
{
if(threads[i]!=null)
{
send=br.readLine();
threads[i].out.println("Server:"+send);
}
}*/
while(true)
{
message = is.readLine();
//message equals to close..terminate the connection
if(message.equals("close"))
{
break;
}
for(int i = 0;i < maxclients;i++)
{
if(threads[i] != null)
{
threads[i].out.println(name + ">" +message);
}
}


System.out.println(name + ">" +message+"\n");//console
}
for(int i = 0;i < maxclients;i++)
{
if(threads[i] != null)
{
threads[i].out.println("The user " + name+ " left the chat ");
}
}
System.out.println("The user " + name + " left the chat\n");
out.println("Bye "+name);
System.out.println("Bye "+name+"\n");
for(int i = 0;i < maxclients;i++)
{
if(threads[i] == this)
{
threads[i] = null;//current thread variable null so new client thread accepted by the server
}
}
//close connection
is.close();
out.close();
}
catch(IOException e)
{
System.out.println(e);
}
}//enf of run method
}
Client:
import java.io.*;
import java.net.*;
public class MulClientThread implements Runnable
{
//declaration
static int port = 1774;
static String host = "192.168.1.113";
static Socket soc = null;
static BufferedReader input = null;
static DataInputStream is = null;//receive response from server
static boolean end = false;
static PrintStream ps = null;//send data to server
public static void main(String args[])throws IOException
{
//start of main method
soc = new Socket(host,port);//socket creation for communication
System.out.println("chat started using multi thread on port "+port+"\n on host "+host);
//input and output stream communication with server
input = new BufferedReader(new InputStreamReader(System.in));
ps = new PrintStream(soc.getOutputStream());
is = new DataInputStream(soc.getInputStream());
String receive;
BufferedReader in=new BufferedReader(new InputStreamReader(soc.getInputStream()));

//write the data to socket
if(soc != null&&ps != null&&is != null)
{
try
{
//Create a thread to read from the server
new Thread(new MulClientThread()).start();
while(!end)
{
ps.println(input.readLine());
}


}
catch(IOException ex)
{
System.out.println("IO Exception"+ex);
}
}
}
public void run()
{
//read from the server
String message;
try
{
while((message = is.readLine()) != null)
{
System.out.println(message);
if(message.equals("close"))
{
//message equals close terminate the connection
break;
}
}
if(soc!=null)
{
//close the connection
soc.close();
System.out.println("connection terminated....");
System.exit(0);
}
end=true;
}
catch(IOException x)
{
System.out.println("IO Exception "+x);
}
}//end of run method
}//end of main method

Hello.
Do you have understanding of client/server communication?
Next, are you familiar with Java API for doing client/server communication - be it one way or two way?
Try this book: http://www.mdp.ac.id/materi/2012-201...1061-908-1.pdf

Syed.

Hello
I had an experience by Server/Client and I understood it is too hard.
The code below is my experience. If you use this code in one station by two cmd window the code works very well. If you use it in two separate stations, your LAN and the windows settings should be OK. In my experience, client code couldn't find the server in some of the stations in my office!
good lock

server code:

import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
 
public class TalkServer {
	private static Scanner ScreenInput;
	private static ServerSocket SServer;
	private static Scanner socketIN;
	public static void main(String[] args)
	{
		System.out.println("TalkServer Version 1.0");
		System.out.print("Type the port: ");
		ScreenInput = new Scanner(System.in);
		String sPort=ScreenInput.nextLine();
		int iPort=Integer.parseInt(sPort);
		System.out.println("Port Nomber is:"+iPort);
		System.out.println("Wait for a client...");
 
		try
		{
			SServer = new ServerSocket(iPort);
			Socket SClient;
			SClient=SServer.accept();
			String client;
			client = SClient.getInetAddress().toString();
			System.out.println("Connected to " + client);
			socketIN = new Scanner(SClient.getInputStream());
			PrintWriter SocketOut;
			SocketOut=new PrintWriter(SClient.getOutputStream(),true);
			while (true)
			{
				System.out.print("Listening for Client:");
				String sInput=socketIN.nextLine();
				System.out.println(sInput);
				SocketOut.println("Server:"+sInput);
				if (sInput.equalsIgnoreCase("bye"))
					break;
			}
			SClient.close();
			SServer.close();
			System.out.println("Server closed");
		}
		catch(Exception e)
		{
			e.printStackTrace();
			System.out.println("Error in connection");
		}
	}
}

Client code:

import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
 
public class TalkClient {
	private static Scanner keyBoard;
	private static Scanner socketIN;
 
	public static void main(String[] args)
	{
		System.out.println("TalkClient Version 1.0");
		System.out.print("Type the port:");
		keyBoard = new Scanner(System.in);
		String sPort=keyBoard.nextLine();
		int iPort=Integer.parseInt(sPort);
		System.out.println("Port Nomber is "+iPort);
		System.out.print("Type the Host:");
		String sHost=keyBoard.nextLine();
		Socket s;
		InetAddress ip;
		try
		{
			ip=InetAddress.getByName(sHost);
			System.out.println("This Host has The IPs below:");
			InetAddress[] address=InetAddress.getAllByName(sHost);
			for (InetAddress iIP: address)
				System.out.println(iIP.toString());
			System.out.println("Now Connecting to the Server...");
			s=new Socket(ip,iPort);
			System.out.println("Connected to "+iPort);
			socketIN = new Scanner(s.getInputStream());
			PrintWriter SocketOut;
			SocketOut=new PrintWriter(s.getOutputStream(),true);
			while(true)
			{
				System.out.print("Say something:");
				String sSay=keyBoard.nextLine();
				SocketOut.println(sSay);
				String sListen=socketIN.nextLine();
				System.out.println("check back:"+sListen);
				if (sSay.equalsIgnoreCase("bye")) break;
			}
		}
		catch (UnknownHostException e)
		{
			System.out.println("the hos t is unknown");
		}
		catch (IOException e)
		{
			System.out.println("Netwerk Error");
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}
}