is JApplet an instance of ActionListner according to this code?

[Anil Deshpande]

This is a code which demonstrates the use of JRadioButton

 // Demonstrate JRadioButton
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/*
  <applet code="JRadioButtonDemo" width=300 height=50>
  </applet>
*/

public class JRadioButtonDemo extends JApplet
implements ActionListener {
  JLabel jlab;

  public void init() {
    try {
      SwingUtilities.invokeAndWait(
        new Runnable() {
          public void run() {
            makeGUI();
          }
        }
      );
    } catch (Exception exc) {
      System.out.println("Can't create because of " + exc);
    }
  }

  private void makeGUI() {

    // Change to flow layout.
    setLayout(new FlowLayout());

    // Create radio buttons and add them to content pane.
    JRadioButton b1 = new JRadioButton("A");
    b1.addActionListener(this);
    add(b1);

    JRadioButton b2 = new JRadioButton("B");
    b2.addActionListener(this);
    add(b2);

    JRadioButton b3 = new JRadioButton("C");
    b3.addActionListener(this);
    add(b3);

    // Define a button group.
    ButtonGroup bg = new ButtonGroup();
    bg.add(b1);
    bg.add(b2);
    bg.add(b3);

    // Create a label and add it to the content pane.
    jlab = new JLabel("Select One");
    add(jlab);
  }

  // Handle button selection.
  public void actionPerformed(ActionEvent ae) {
    jlab.setText("You selected " + ae.getActionCommand());
  }
}
   

At line number 35,39 and 43, they write a code
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);

My class itself give the implementation of actionPerformed() method

My Problem with this code is how come we can write addActionListener(this) when addActionListener() takes ActionListener as the argument. Does this code mean My class implements ActionListener
by overrriding actionPerformed method(). How did my class became a ActionListener even though i have not declared my class as such.

Please explain?

[Ulf Dittmer]

Does this code mean My class implements ActionListener by overrriding actionPerformed method.

Sort of. It becomes an ActionListener by having an actionPerformed method AND by declaring that it implements the ActionListener interface.

How did my class became a ActionListener even though i have not declared my class as such.

Yes, you have - look at line 11.

[Anil Deshpande]

Yeah, really silly query. Just in hurry I didn't see the code at line 11. Any way thanks a lot. I realized what I did just after I posted the query

[Rob Camick]

I realized what I did just after I posted the query

Then why didn't you reply to the posting stating you solved the problem, so we don't waste time answering a question that has already been answered. That kind of behaviour will NOT get you help in the future.

[Anil Deshpande]

Well before I could you had replied sir. Don't take any offense. Some times just things happen