[Suzanne]

I hve written a server program & a client program. The server is supposed to echo watever is typed in the client. I hve to get 16 values to be echoed. I hve created a string and all the values are added to this string. When I pass the string to the server, it doesn get echoed by the server. In fact server hangs @ tat part after establishing connection with the client. I am at my wits end!Can someone pls suggest why my program hangs @ server end? I hve absolutely no clue.

SERVER:

Code:

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

public class AS3{
    public static void main(String[] args ){
        int i = 1;
        try{
             ServerSocket s = new ServerSocket(9001);

             for (;;){
                 Socket incoming = s.accept( );
                 System.out.println("Spawning " + i);
                 new RealEchoHandler(incoming, i).start();
                 i++;
             }
        } catch (Exception e){ System.out.println(e); }
    }
}

class RealEchoHandler extends Thread{
	DataInputStream in;
	DataOutputStream out;
	private Socket incoming;
    private int counter;

    public RealEchoHandler(Socket i, int c){
        incoming = i;
        counter = c;
    }

    public void run(){
        try {

            in = new DataInputStream(incoming.getInputStream());
			out = new DataOutputStream(incoming.getOutputStream());

            boolean done = false;
            String str="";
            out.writeUTF("Connected!\n");
            out.flush();
            while (!done){
				out.writeUTF(">");
				out.flush();
                str = in.readUTF();
                System.out.println(in+":"+str);
                if (str == null)
                    done = true;
                else{
                    out.writeUTF("Echo (" + counter + "): " + str+"\n");
                    out.flush();
                }
            }

            incoming.close();
         } catch (Exception e){
             System.out.println(e);
         }
    }


}

CLIENT:

Code:

 import java.io.*;
import java.net.*;
import java.util.*;
class Client3{
	public static void main(String[] args) {
		String store="";
		String clientCar="";
		String clientBranch="";
		String clientDriver="";
		String clientPasswd="";

		DataOutputStream out;
		DataInputStream in;
		try {
		    Socket t = new Socket("127.0.0.1", 9001);

            in = new DataInputStream(t.getInputStream());
            out = new DataOutputStream(t.getOutputStream());
            BufferedReader br = new BufferedReader
                     (new InputStreamReader(System.in));
            boolean more = true;
			System.out.println(in.readUTF());
            while (more) {
				clientCar = in.readUTF();
                clientBranch = in.readUTF();
				clientDriver = in.readUTF();
				clientPasswd = in.readUTF();
                store = store + clientCar+clientBranch+clientDriver+clientPasswd;
			    
                out.flush();
				store = in.readUTF();
                if (store == null)
                    more = false;
                else
                    out.writeUTF(store + "\n");
            }

         } catch(IOException e){
			    System.out.println("Error" + e);
	     }
	     System.out.println(store);
     }
}

[UnrealEd]

At first glance, I'd say the problem lies within this code-snippet of the EchoHandler class (in the run method):

Code:

if (str == null)
                    done = true;

This code states that when the input is empty (null), the client is done, and should stop the while loop and proceed (closing the connection with the client). That's not what you need. The loop has to continue untill the client disconnects (or send a terminator message), but when the client doesn't send anything, the loop should still be in place.