Passing input from JButton to console

Question

statsButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e){

              //Return the string "stats" to gameLoop() as cmd
            }
        }); 

public void gameLoop(){
        Scanner lineScanner = new Scanner(System.in);
        cmd = "";

        System.out.print(getBoard().printBoard(false));

        while (!cmd.equals("quit")) {
            System.out.print(">");
            Scanner wordScanner = new Scanner(lineScanner.nextLine());

        if (wordScanner.hasNext()) {
            cmd = wordScanner.next();
            if (cmd.equals("board")) {
                System.out.print(getBoard().printBoard(false));
                } else if (cmd.equals("ships")) {
            System.out.print(getBoard().printBoard(true));
                } else if (cmd.equals("help")) {
                    printHelp();    
                } else if (cmd.equals("stats")) {
                    printStats();
                } else if (cmd.equals("fire")) {
            if(fire(wordScanner)) { 
            printStats();
            cmd = "quit";
                    }
                } else if (cmd.equals("quit")) {    
                } else if (!cmd.equals("")) {
                    System.out.println(ILLEGAL_COMMAND);
                }
            }

        }
    }

What I'm trying to do is that when the user clicks the statsButton, the String cmd in the gameLoop would be changed to "stats". The statsButton and the gameLoop() are located in two different classes. Anyone can give me an idea how to do it? (I've attempted pipedreader/pipedwriter) and I just can't seem to get it right.

*I'm basically trying to make my console application into a GUI application without changing the original console application.

Edit: What I've tried

Class textBased 
PipedInputStream in = new PipedInputStream()

public void gameLoop(){
    try{
        in.connect(GUIclass.out);

    Scanner lineScanner = new Scanner(in);`

Class GUIclass  
    PipedOutputStream out = new PipedOutputStream();
    PrintWriter writer;

  public GUIclass(){
    final PrintWriter writer = new PrintWriter(out);
    statsButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e){

              writer.println("stats");
             }
          }); 

that's what I tried writing but it doesn't seem to work.

Answer 1

Regarding

I'm basically trying to make my console application into a GUI application without changing the original console application..."

My advice is simple: "don't do it".

The two applications have completely different structure, one being linear, the other being event-driven, and are not directly translatable to each other. Better to make a new GUI program from the ground up. Now if your non-GUI application contains some well-structured and behaved object-oriented classes, then by all means use those classes in your GUI's "model" or logic section, but don't try to directly translate the program flow of one type of application to the other.

Edit
Based on your posted requirements:

"You should be able to play your Battleship game through your GUI interface. In addition, the text-based front-end you wrote for project 1 should still "work" and be playable."

Correct me if I'm wrong, but I'm betting that you have several classes involved here, and only one of them is the "text-based front-end". If so, then use the non front-end classes as the model of your GUI as I suggested above, but do not use the text-based front-end for anything GUI related, and do not try to emulate it in your GUI.

Answer 2

Have the console application instantiate the button ActionListener and pass it to the UI. When the action event is fired, the listener will tell the console app that it happened. The method in the ActionListener will tell it what to do.