Client Server application code

[mark10]

Hello!I am new in this site and wish to improve my java clent server application code.It's to connect the client to the server through a port and random jokes request by the client to the server be sent to the client.

Thanks

[horace1]

a simple server which waits for message from a client

// server which waits for messages from a client
import java.io.*;
import java.util.*;
import java.net.*;


public class TCPserver extends Thread
{
        private ServerSocket   serverSocket;
        ObjectInputStream br=null;
        ObjectOutputStream pw=null;
        int receivePort;                // port to receive  from
        boolean threadRunning = true;   // flag to terminate thread

        TCPserver(int receivePort)    // constructor to receive datagrams on port receivePort
    {
                this.receivePort = receivePort;
    }

        // terminate the thread by setting flag
        public void stopTCPserver()
        {
                threadRunning = false;
        }

        public void run()                // thread run method, receives and buffers datagrams
        {
          Socket socket=null;
          try
              {
              while (threadRunning)
              {
                  System.out.println("TCP server starting: IP address " 
                       + InetAddress.getLocalHost().toString() + " port " + receivePort );
                  serverSocket = new ServerSocket(receivePort);
                  socket = serverSocket.accept(); // Wait for client to connect.
                  System.out.println("Client connect from IP address " + socket.getInetAddress()
                                  + " port " + socket.getPort());
                  br  = new ObjectInputStream( ( socket.getInputStream() ) );
                  pw = new ObjectOutputStream( socket.getOutputStream() );
                  while(threadRunning)
                    try
                    {
                      String code = (String) br.readObject();
                      System.out.println( "Server received string: '" + code + "'");
                    }
                    catch (Exception se) {System.err.println("done"); break;}
                  serverSocket.close();
                }
              }
          catch (Exception se) {System.err.println("run() " + se); }
     
          System.exit(1);                                                 // exit on failure
        }


public static void main(String args[])
{
        int receivePort=9000;                                 // port to receive datagrams on
        TCPserver frameInput = new TCPserver(receivePort);    // create server to receive messages
        frameInput.start();                                   // and start it
        System.out.println("ready to receive datagrams from socket " + receivePort);
        }

}

a simple client which sends messages entered at keyboard to the server

// client which sends a message to a server using TCP

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

public class TCPclient
{

        static void sendString(String remoteIPaddress, int remotePort)
        {
        Socket         socket1;        // To server.
        ObjectOutputStream        objOut;        // To write to server.
                try
                {
                 socket1 = new Socket( remoteIPaddress, remotePort );   
                 objOut = new ObjectOutputStream( socket1.getOutputStream() );
                 System.out.println("Server contacted OK sending " );
                 while(true)
                   {
                     String s = in.readLine();
                     objOut.writeObject(s);         // send message three times
                   }  // end try
                }
                catch (UnknownHostException e) {System.err.println("SendString " +  e); }
                catch (SocketException se) {System.err.println("SendString " +  se); }
                catch (IOException e) {System.err.println("SendString " +  e); }
        }

  private final static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
public static void main(String args[])
{
   System.out.println("enter message to send to server");
   TCPclient.sendString("127.0.0.1", 9000);
}

}

1. compile the server and run it
2. compile the client and run it
3. message typed in a client appear at server