如何停止GUI无限打印文本？ -Java

Question

I have created a GUI that will print out a list every time you press a key. Or so I thought... But instead of running the function I've made on the key press, the GUI just does it all the time.

Here's my code:

package main;

import java.util.ArrayList;
import javax.swing.*;
import java.awt.*;

public class Elements{
    static ArrayList<String> composition = new ArrayList<String>();
    static Boolean x = true;
    static JLabel gLabel = GUI();
    public static void main(String[] args){
        while(x == true){
            gLabel.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("Q"), "water");
            gLabel.getActionMap().put("water", water());
            gLabel.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("W"), "life");
            gLabel.getActionMap().put("life", life());
        }
    }
    public static Action water(){
        if(composition.contains("Fire")){
            composition.remove("Fire");
            composition.add("Steam");
        } else if(composition.contains("Cold")){
            composition.remove("Cold");
            composition.add("Ice");
        } else if(composition.contains("Arcane")){
            composition.remove("Arcane");
            composition.add("Poison");
        } else if(composition.contains("Lightning")){
            composition.remove("Lightning");
        } else {
            composition.add("Water");
        }
        int y = 0;
        while(y < 100){
            System.out.println("");
            y++;
        }
        System.out.println(composition);
        x = true;
        return null;
    }
    public static Action life(){
        if(composition.contains("Arcane")){
            composition.remove("Arcane");
        } else {
            composition.add("Life");
        }
        int y = 0;
        while(y < 100){
            System.out.println("");
            y++;
        }
        System.out.println(composition);
        x = true;
        return null;
    }
    private static JLabel GUI(){
        JFrame frame = new JFrame("KeyPress Handler");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel label = new JLabel("This window listens for key presses and does stuff with them. Isn't that cool?");
        label.setPreferredSize(new Dimension(175, 100));
        frame.getContentPane().add(label, BorderLayout.CENTER);

        frame.pack();
        frame.setVisible(true);
        return label;
    }
}

Instead of running life() and water() on a key press, it runs them all the time .

I get the output of,

[Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life, Water, Life]

without touching anything !

I have got no idea why this is happening but I think it has to do with the: gLabel.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("Q"), "water");

and the:

gLabel.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("W"), "life");

If anyone could tell me what the problem is and how to fix it, that would be great.

Thanks, Helen

PS: I added 2 new lines: gLabel.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke("Enter"), "stop"); gLabel.getActionMap().put("stop", stop());

The function stop() is as follows:

public static Action stop(){ x = false; return null;

As I understand it, this is meant to add a new key binding of stop() to Space .

Also, after making these changes, the output was reduced to [Water, Life] .

(Also, fixed the while loop)

Answer 1

while(x = true){ --> somehow you have to set x boolean variable false in your while condition. There is nothing else in your while loop.

Answer 2

while ( x = true ) has to be changed to while while ( x == true )

and you'll have to make it possible in your code (wherever, not especially in your main since x is a static variable) to change the value of x to false.

That said, I'm not sure what you're trying to achieve and I think you're going in the wrong direction.