Muti-Threaded Echo Server and Corresponding GUI Client in Java

/* Muti-Threaded Echo Server and Corresponding GUI Client in Java */

// EchoServer.java

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

public class EchoServer
{        
    ServerSocket ss;
    
    
    public EchoServer() 
    {
        try
        {
            ss = new ServerSocket(12111);
        }
        catch(Exception e)
        {
            System.out.println("Error ... " + e.getMessage());
            System.exit(-1);
        }
        
        System.out.println("Listening for clients.....");
       
        int id = 0;
        while(true)
        {                        
            try
            {
                Socket cs = ss.accept();
            
                ClientServiceThread ct = new ClientServiceThread(cs, id++);
                ct.start();
            }
            catch(Exception e)
            {
                System.out.println(" Error " + e.getMessage());
                System.exit(-1);
            }
        }
    }
    
    public static void main (String[] args)
    {
        new EchoServer();    
    }

    
    class ClientServiceThread extends Thread
    {
        Socket cs;        
        int m_clientID = -1;
        boolean m_bRunThread = true;
        
        ClientServiceThread(Socket s, int clientID)
        {
            cs = s;
            m_clientID = clientID;
        }
       
        public void run()
        {            
           BufferedReader in = null; 
            PrintWriter out = null;

            System.out.println("Accepted Client : ID - " + m_clientID + " : Address - " + cs.getInetAddress().getHostName());
                
            try
            {                                
                in = new BufferedReader(new InputStreamReader(cs.getInputStream()));
                out = new PrintWriter(new OutputStreamWriter(cs.getOutputStream()));

                while(m_bRunThread)
                {                    
                    String clientCommand = in.readLine();
                    
                    System.out.println("Client Says :" + clientCommand);
                    
                    
                    if(clientCommand.equalsIgnoreCase("exit"))
                    {
                        m_bRunThread = false;   
                        System.out.print("Stopping client thread for client : " + m_clientID);
                        System.exit(-1);    
                    }
                    else
                    {
                        out.println(clientCommand);
                        out.flush();
                    }
                }
                    in.close();
                    out.close();
                    cs.close();
                    System.out.println("...Stopped");
                }
                catch(Exception e)
                {
                    System.exit(-1);
                }
        }
    }
}

// EchoClient.java

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

public class EchoClient
{
    public static void main(String args[])
    {

        Socket s = null;

        try
        {
            s = new Socket("localhost", 12111);
        }        
        catch( Exception e)
        {
               System.out.println("Error ... " + e.getMessage());
            System.exit(-1);
        }

        if(s == null)
            System.exit(-1);
        
        BufferedReader in = null;
        PrintWriter out = null;
        
        try
        {
            in = new BufferedReader(new InputStreamReader(s.getInputStream()));
            out = new PrintWriter(new OutputStreamWriter(s.getOutputStream()));
            BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
            String msg;
            while(true)
            {
            System.out.print(" Enter the Message : " );
            msg=br.readLine();
            if(msg.compareTo("exit")==0)
            {
                out.println(msg);
                out.flush();
                break;
            }

            out.println(msg);
            out.flush();

            System.out.println(" Server Says : " + in.readLine());
            }
                out.close();
                in.close();
                s.close();
            }
            catch(Exception e)
            {
                System.out.println("Error ... " + e.getMessage());
                System.exit(-1); 
            }                       
    }
}

OUTPUT : 

// EchoServer.java 

javac EchoServer.java
java EchoServer

Listening for clients.....
Accepted Client : ID - 0 : Address - localhost
Client Says :Welcome To JCE
Client Says :I am Baran
Client Says :CSE Rocks .....
Client Says :exit
Stopping client thread for client : 0


// EchoClient.java 

javac EchoClient.java
java EchoClient

 Enter the Message : Welcome To JCE
  Server Says : Welcome To JCE
 Enter the Message : I am Baran
 Server Says : I am Baran
 Enter the Message : CSE Rocks .....
 Server Says : CSE Rocks .....
 Enter the Message : exit

If u find any flaws , Contact to M.Baran Mahamood