Threaded Application won't run.

[Rob Brew]

What gives?

package chatserver;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Rob
 */
public class ChatServer {
    int x[] = new int[4];
    int y[] = new int[4];
    BufferedReader reader;
    PrintWriter writer;
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        ChatServer server = new ChatServer();
        server.run();
        
        
     
    }

    
    public void run() {
        System.out.println("hello");
        connect();
        Thread readerThread = new Thread(new IncomingReader());
        Thread writerThread = new Thread(new OutgoingWriter());
        readerThread.start();
        writerThread.start();
    }
    
    public  void connect() {
          try {
            ServerSocket serverSock = new ServerSocket(4242);
            
            while (true) {
                Socket sock = serverSock.accept();
                writer = new PrintWriter(sock.getOutputStream());
                reader = new BufferedReader(new InputStreamReader(sock.getInputStream()));
                System.out.println("NEtowrking established");
             }
        } catch (IOException ex) {
           ex.printStackTrace();
        }
        
    }

        public class IncomingReader implements Runnable {
            public void run() {
            try {
                String result = reader.readLine();
                reader.close();
                System.out.println("read " + result);
                writer.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            }
        }

        public class OutgoingWriter implements Runnable {
            public void run() {
                writer.println("hello");
                System.out.println("Written");
                }
                              
            }
}

[Bear Bibeault]

Perhaps an expanded definition of "won't run" might be helpful.

[Matthew Brown]

Does your connect() method ever exit?

[Rob Brew]

public void run won't execute, and from that the rest of the program is started.

[Rob Brew]

connect() doesn't get called because void run() is never called.

[Rob Brew]

ah, hang on.

I'm using NetBeans and was actually running ChatClient when i hit run.

Goes to stand in a corner.

Ignore this please.

[Rob Spoor]

Matthew is still right. Your connect() method contains a while (true) loop that only ends when an exception occurs, and therefore the entire method will only end when an exception occurs.

Other than that, you will overwrite reader and writer for every new connection. They should become local variables instead, which you then pass to the runnables:

package chatserver;   
   
import java.io.BufferedReader;   
import java.io.DataInputStream;   
import java.io.IOException;   
import java.io.InputStreamReader;   
import java.io.PrintWriter;   
import java.net.ServerSocket;   
import java.net.Socket;   
import java.util.logging.Level;   
import java.util.logging.Logger;   
   
/**  
 *  
 * @author Rob  
 */   
public class ChatServer {   
    int x[] = new int[4];   
    int y[] = new int[4];   

    /**  
     * @param args the command line arguments  
     */   
    public static void main(String[] args) {   
        ChatServer server = new ChatServer();   
        server.run();   
           
           
        
    }   
   
       
    public void run() {   
        System.out.println("hello");   
        connect();   
    }   
       
    public  void connect() {   
          try {   
            ServerSocket serverSock = new ServerSocket(4242);   
               
            while (true) {   
                Socket sock = serverSock.accept();   
                PrintWriter writer = new PrintWriter(sock.getOutputStream());   
                BufferedReader reader = new BufferedReader(new InputStreamReader(sock.getInputStream()));   
                System.out.println("NEtowrking established");   
                Thread readerThread = new Thread(new IncomingReader(reader));   
                Thread writerThread = new Thread(new OutgoingWriter(writer));   
                readerThread.start();   
                writerThread.start();   
             }   
        } catch (IOException ex) {   
           ex.printStackTrace();   
        }   
           
    }   
   
        public class IncomingReader implements Runnable {   
            private BufferedReader reader;

            public IncomingReader(BufferedReader reader) {
                this.reader = reader;
            }

            public void run() {   
            try {   
                String result = reader.readLine();   
                reader.close();   
                System.out.println("read " + result);   
                writer.close();   
            } catch (IOException ex) {   
                ex.printStackTrace();   
            }   
            }   
        }   
   
        public class OutgoingWriter implements Runnable {   
            private PrintWriter writer;

            public OutgoingWriter(PrintWriter writer) {
                this.writer = writer;
            }

            public void run() {   
                writer.println("hello");   
                System.out.println("Written");   
                }   
                                 
            }   
}  

Now each connection will have its own reader/writer pair and its own handling threads.

[Rob Brew]

Using the same format for ChatServer i build ChatClient, both Server and Client send data but it doesn't noticeably get received.

ChatClient.java

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package chatclient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

/**
 *
 * @author Rob
 */
public class ChatClient {

    BufferedReader reader;
    PrintWriter writer;
    Socket sock;

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        ChatClient client = new ChatClient();
        client.SetUpNetworking();
    }

    private void SetUpNetworking() {
        try {
            sock = new Socket("127.0.0.1", 4242);
            InputStreamReader streamReader = new InputStreamReader(sock.getInputStream());
            reader = new BufferedReader(streamReader);
            writer = new PrintWriter(sock.getOutputStream());
            System.out.println("Netowrking Established");
            Thread readerThread = new Thread(new IncomingReader(reader));
            Thread writerThread = new Thread(new OutgoingWriter(writer));
            readerThread.start();
            writerThread.start();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
    class IncomingReader implements Runnable{
        private BufferedReader reader;
        
        public IncomingReader(BufferedReader reader) {
        this.reader = reader;
    }
        
            public void run() {   
            try {   
                String result = reader.readLine();   
                reader.close();   
                System.out.println("read " + result);   
                   
            } catch (IOException ex) {   
                ex.printStackTrace();   
            }   
        
    }
    }
            public class OutgoingWriter implements Runnable {   
            private PrintWriter writer;

            public OutgoingWriter(PrintWriter writer) {
                this.writer = writer;
            }

            public void run() {   
                writer.println("hello");   
                System.out.println("Written");   
                }   
                                 
            }   
    }