Registering an action listener interface

Question

How do i register an action listener interface to a java program which has three textfields and three buttons. addition,multiplication and subtraction respectively so that when i click on a button it sums,multiply,and subtracts the numbers and displays the output in the third textfield box using the swing components.

Answer 1

** BUT a more important point i wanted to
express/share is that... it is actually better if we
TRY to avoid using ActionCommand while
handling such scenarios !!!Let me show the way i modified the Calculate.java pgm..
(Thanks to @Wildcard82 )
//~~~~~~~~~~~~
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Calculate extends JFrame implements ActionListener
    private static final long serialVersionUID = -1558653254398328438L;
    private JTextField field1, field2, field3;
    private JButton add, subtract, multiply;
    // HAVE to be instance fields now...
    // so that they're visible in the actionPerformed() method...! :)
    private enum Operations{
        add,subtract,multiply
    public Calculate()
        setLayout(new GridLayout(2,3));
        field1=new JTextField(5);
        field2=new JTextField(5);
        field3=new JTextField(5);
        add = new JButton("add");
        //add.setActionCommand("add"); // * NO need to set the Action-Command..!
        add.addActionListener(this);
        subtract = new JButton("subtract");
        subtract.addActionListener(this);
        multiply = new JButton("multiply");
        multiply.addActionListener(this);
        add(field1);add(field2);add(field3);
        add(add); add(subtract); add(multiply);
    } /* default c'tor */
     * @param args
    public static void main(String[] args)
        Calculate c = new Calculate();
        c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        c.setVisible(true);
        c.pack();
    } /* end main() */
     * A simpler & nicer version of actionPerformed() that works
     * even when you internationalize your Calculator App...
     * ..since, it does NOT depend on Action-Commands but just on the
     * Event-Source objects, which DON"T change when you do I18N...! :)
    public void actionPerformed(ActionEvent ae)
        Object source = ae.getSource();
        if(source==add)calculate(Operations.add);       
        else if(source==subtract)calculate(Operations.subtract);       
        else if(source==multiply)calculate(Operations.multiply);       
    } /* end method() */
    private void calculate(Operations operation)
        int n1, n2;
        n1=Integer.parseInt(field1.getText());
        n2=Integer.parseInt(field2.getText());
        if(operation==Operations.add)
            field3.setText(String.valueOf(n1+n2));
        else if(operation==Operations.subtract)
            field3.setText(String.valueOf(n1-n2));
        else if(operation==Operations.multiply)
            field3.setText(String.valueOf(n1*n2));
         else
            field3.setText("");
    } /* end method() */
} /* end class */
//~~~~~~~~~~~~
Thanks,
"r a g h u"
// [email protected]