Simple client/server gui char with thread

Hello.

I write out a simple messaging client / server. I have already written a console application, which works fine but I wanted to write desktop application.
And there is a problem because when I create a connection to the program I got Exception.

I can say that the same code in the console is working properly.

Sorry for my english.

Here I start connecting:

Code:

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    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { 
     
            String sPort=jComboBox1.getSelectedItem().toString(); 
            int port = Integer.parseInt(sPort); 
            try{ 
            ServerSocket serverSocket = new ServerSocket(port); 
            jTextArea1.append("Server waiting for client on port " + serverSocket.getLocalPort()+"\n"); 
            } 
            catch (Exception e){} 
            jTextArea1.append("Server waiting for connection \n"); 
     
            new Thread (new newSocket(serverSocket,jTextArea1)).start(); 
            jButton1.setEnabled(false); 
        }

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And this is Thread where I got Exception

Code:

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    class newSocket implements Runnable 
    { 
        public newSocket(ServerSocket s,JTextArea _area) 
        { 
            serverSocket=s; 
            jTextArea1=_area; 
        } 
     
        public void run() 
        { 
            try 
            {       
                Socket socket = serverSocket.accept();  //it doesn't work   
                jTextArea1.append("New client asked for a connection");
            } catch(IOException e){e.printStackTrace();  } 
        } 
     
        private JTextArea jTextArea1; 
        private ServerSocket serverSocket; 
    }

---

Exception:

Code:

---

Exception in thread "Thread-3" java.lang.NullPointerException
        at serwer.ClientSocket.run(SerwerView.java:317)
        at java.lang.Thread.run(Thread.java:619)

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