Error with Client and Server using Socket

[jin Otanashi]

I'm working on a message server to client but somehow i'm not getting any reply from either message
here part of the code

public class messageClient {
    public static void main(String [] args) throws Exception {
    Socket serverSocket = new Socket(args[0], SERVER_PORT);
    String myReply="";
    PrintWriter toServer = new PrintWriter(serverSocket.getOutputStream(), true);
    BufferedReader fromServer = new BufferedReader(new InputStreamReader(serverSocket.getInputStream()));
    BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in));
 
    String incoming = "";
    String endstr = "end";
    String stopc = "over";
    
    while (true){
    	
    	while (true){
    		incoming = fromServer.readLine();
    	
        System.out.println(incoming);
       if ((incoming.compareTo(stopc) == 0) || 
    	  (incoming.compareTo(endstr) == 0))
    	   break;
    	}
    	if (incoming.compareTo(endstr) == 0)
    		break;
        System.out.print("Your turn> ");
        
        while (true){
        myReply = keyboard.readLine();
        toServer.println(myReply);
        if ((myReply.compareTo(stopc) == 0) || 
          	  (myReply.compareTo(endstr) == 0))
        break;
        System.out.println(">>");
        }
        if (myReply.compareTo(endstr) == 0)
        	break;
    	}
    	System.out.println("...");
    	}
        
 
    
    final static int SERVER_PORT = 3333;
}

and the other

public class messageService {
    public static void main(String [] args) throws Exception {
    ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
    System.err.println("Waiting for a client");
    Socket clientSocket = serverSocket.accept();
 
    System.out.println("Connection requested from: " + clientSocket.getLocalAddress());
    String myReply = "";
    PrintWriter toClient = new PrintWriter(clientSocket.getOutputStream(), true);
    BufferedReader fromClient = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
    BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in));
    String endstr = "end";
    String stops = "over";
    String incoming= " ";
   while (true){
    	
   	while (true){
    		
    toClient.println("Whatcha want?");
    incoming = fromClient.readLine();
    if ((incoming.compareTo(stops) == 0) || 
      	  (incoming.compareTo(endstr) == 0))
      	   break;
    } 
        System.out.println(incoming);
    	if (incoming.compareTo(endstr) == 0)
    		break;
        System.out.print("Your turn> ");
    while (true){
        myReply = keyboard.readLine();
        toClient.println(myReply);
        if ((myReply.compareTo(stops) == 0) || 
            	  (myReply.compareTo(endstr) == 0))
          break;
          }
        if (myReply.compareTo(endstr) == 0)
        	break;
    }
 
    }
 
    final static int SERVER_PORT = 3333;
}

[Anayonkar Shivalkar]

Hi jin,

Not sure if you want to make a chat server or echo server but below are my findings:

In Server code, below part sends message to client:

toClient.println("Whatcha want?");

But, at client side, the code is reading that line, printing it and breaking while(true) loop (first inner loop) only if that message is stop or end. However, that message is 'Whatcha want?'. Thus, loop will not break, and client is waiting for another message from server.
Meanwhile, server is also waiting for another message from client:

incoming = fromClient.readLine();

I think at client side, if the message (from server) is not end/stop, then you should give client a chance to send a message to server.

I hope this helps.

[jin Otanashi]

Anayonkar Shivalkar wrote:Hi jin,

Not sure if you want to make a chat server or echo server but below are my findings:

In Server code, below part sends message to client:

toClient.println("Whatcha want?");

But, at client side, the code is reading that line, printing it and breaking while(true) loop (first inner loop) only if that message is stop or end. However, that message is 'Whatcha want?'. Thus, loop will not break, and client is waiting for another message from server.
Meanwhile, server is also waiting for another message from client:

incoming = fromClient.readLine();

I think at client side, if the message (from server) is not end/stop, then you should give client a chance to send a message to server.

I hope this helps.

thank you so much for the explanation now the program is working fine. ( the program does reply the server and client )