java - How to add action listener that listens to multiple buttons

Question

I'm trying to figure out what i am doing wrong with action listeners. I'm following multiple tutorials and yet netbeans and eclipse are giving me errors when im trying to use an action listener.

Below is a simple program that im trying to get a button working in.

What am i doing wrong?

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;


public class calc extends JFrame implements ActionListener {



    public static void main(String[] args) {

        JFrame calcFrame = new JFrame();

        calcFrame.setSize(100, 100);
        calcFrame.setVisible(true);

        JButton button1 = new JButton("1");
        button1.addActionListener(this);

        calcFrame.add(button1);
    }

    public void actionPerformed(ActionEvent e) {
        if(e.getSource() == button1)
    }  

}

the action listener is never registered because with the if(e.getSource() == button1) it cant see button1, errors saying cannot find symbol.

Answer 1

There is no this pointer in a static method. (I don't believe this code will even compile.)

You shouldn't be doing these things in a static method like main(); set things up in a constructor. I didn't compile or run this to see if it actually works, but give it a try.

public class Calc extends JFrame implements ActionListener {

    private Button button1;

    public Calc()
    {
        super();
        this.setSize(100, 100);
        this.setVisible(true);

        this.button1 = new JButton("1");
        this.button1.addActionListener(this);
        this.add(button1);
    }


    public static void main(String[] args) {

        Calc calc = new Calc();
        calc.setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if(e.getSource() == button1)
    }  

}