线程套接字处理程序，用于在TCP端口中进行双向通信

Question

I want to make a chat application which will be written in java.

One computer will host the server and the other one will initiate the socket [tcp port].

From what I read there should be a loop that will constantly read the socket which means it will make the code is stuck.

I have a button that is 'actionperformed' on mouse release, I want to know if it will work along with the loops that constantly reads the socket so that it will also send the infromation I wrote.

If I must thread it, I want to know if the run() method must be void because if I thread it it will mean creating a new class, and the whole GUI is one big class which includes a text area, and it's private.

Also how can I extract the information from the socket directly to the text area (lets say the textarea variable is called " chatOutput ")?

Answer 1

I presume that this is your situation:

You have a GUI with a text area for typing in chat messages, and a button that will submit new messages to the chat room. You want to keep some panel updated with the stream of chat messages by looping on the Socket's InputStream, but also want to be able to write to the Socket's OutputStream while the InputStream is being looped upon.

This would be my suggestion for the client side code:

Socket con = new Socket(host, port);
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
PrintWriter out = new PrintWriter(con.getOutputStream(), true);
...
Thread t = new Thread(new Runnable() {
    public void run() {
        while(con.isConnected()) {
            String line = in.readLine();
            // update your chat panel with line
        }
    }
});
t.start();
...

And in your action:

...
out.println(/*contents of the text box*/);
// clear contents of text box
// ?update panel?
...

Answer 2

Your question is perhaps a bit vague, but I think the answer to your first question is no,it won't, your infinite while will interfere with normal operation and prevent the event dispatching thread from servicing your listeners. (I am not 100% sure about this but I am trying find out more so long).

The second answer is yes, you need to thread your application as Finbarr suggests. The run method is void, yes, as it is specified by the Runnable interface

Not quite sure what you meant here:

... I thread it it will mean creating a new class, and the whole GUI is one big class which includes a text area, and it's private. ...

Do you want to keep it one class, or what? You can define private classes inside a class if you want to keep one .java file? for some reason.

For communication with your GUI, you can just use something such as a call like this inside your thread that reads the socket:

java.awt.EventQueue.invokeLater(new Runnable() {
  public void run() {
     chatoutput.setText("output text text");
  }
});

You will need to create a class that implements the Runnable interface, and pass your 'chatoutput' variable to it in a constructor, so it can be used to call the above little piece of code.

If you require more complex GUI interaction, see this idea here. GUI/application communication