Question

I’m experiencing some problems with sockets.

I’m trying to make a concurrent server to accept more than one clients.

When a client connects to the server, the server creates a new thread and listens to the socket.
Then, if the client sends something, the server must read it.

On the client i just open a dictionary (txt form) and i send it over the socket.

On the server the only thing i get is this:

#

null

SERVER

    try
             {
                String message,file = new String("StressTextFile.txt");
                File filee = new File(file);
                long length;

                 // Open the file 
                 FileInputStream fstream = new FileInputStream(file);
                 // Get the object of DataInputStream
                 DataInputStream in = new DataInputStream(fstream);
                 BufferedReader br = new BufferedReader(new InputStreamReader(in));
                 String strLine = new String();

                 length  = filee.length();

                 ProgressBar.setMaximum((int)length); //we're going to get this many bytes
                 ProgressBar.setValue(0); //we've gotten 0 bytes so far
                  //Read File Line By Line

                font1 = new Font("Helvetica", Font.PLAIN, 18);
                font1.isBold();
                color = new Color( 74,118,110);
                TextArea1.setForeground(color);
                TextArea1.setFont(font1);

                 int soma=0;
                    while(in.readLine() != null)
                    {
                        strLine = in.readLine();  // reads from file
                        //System.out.println(strLine);


                        TextArea1.append(strLine+"\n");

                        pwOut.write(strLine);
                        pwOut.flush();

                        soma+=strLine.length()+1;
                        ProgressBar.setValue(ProgressBar.getValue()+(strLine.length()+1)*2);
                        ProgressBar.repaint();              
                    };

                    br.close();
                    pwOut.close();
                    Skt.close();
            }catch (Exception e){  System.err.println("Error: " + e.getMessage());  }
          }

CLIENT

    try
    {

        brIn = new BufferedReader(new InputStreamReader(skt.getInputStream()));


        while(s != null)
        {

            s = brIn.readLine();
            System.out.println("#####");
            System.out.println(s);
        }

    } 
    catch (IOException e1) {e1.printStackTrace();    }

Please forget the Swing components.
I think all socket stuff are ok. why can’t i get nothing on the server side?

Please help

Kind regards

Answer 1

A barebones example of a multi-threaded server:

//MyServer.java
public class MyServer {

  private static int PORT = 12345;

  public static void main(String args[]) {

    ServerSocket s = new ServerSocket(PORT);
    while(true) new MyServerThread(s.accept());

  }

And your server thread:

//MyServerThread.java
public class MyServerThread implements Runnable {

  private InputStream in = null;
  private OutputStream out = null;

  public MyServerThread(Socket s) {

    in = s.getInputStream();
    out = s.getOutputStream();

    (new Thread(this)).start();
  }

  public void run() {
    //do stuff with **in** and **out** to interact with client
  }
}

Missing from this example:

• Error handling
• close()ing the sockets/streams
• shutting down the server
• the clientside

Hopefully that gives you some idea of how it usually looks.