Action Listeners

Action Listeners are how Java determines whether or not a button has been pressed. You set each button to have a unique "actionCommand" which identifies which button was clicked. (You can also have mouse Listeners and window listeners and others...). When an action occurs, and a button is clicked, Java runs the code in actionPerformed. An if is set up in this method to run the appropriate code for each button. 

Init Method Code

Silly Fire Station Story Code Description Code
The subdivision plans are drawn up. Get the right libraries, extend the class corectly. import java.awt.*;
import java.awt.event.*;
import javax.swing.*
public class RockPaperScissors extends Applet implements ActionListener
The individual house plans are drawn up..  Buttons are Declared JButton b1;
Construction begins. Construction. b1=new JButton("Hi");
Contractor phones fire station and sets up a special signal for each building so the fire trucks go to the right house. Set specific action command for each button. b1.setActionCommand ("Hi");
Smoke detectors are installed in each house. Add the action listeners.
 b1..addActionListener (this);
don't forget implements ActionListener.
Finish the house, sell it to a happy family. Add the button to the applet. add(b1);

ActionPerformed Method Code.

Silly Fire Station Story Code Description Code
A three year old gets the matches and starts a fire. Button Clicked -
Smoke alarm alerts the fire station. Address is passed with alarm. The button listener catches it and sends a command to java that an event has occured. It passes the ActionCommand for that button - the string "Hi" in this case. ActionPerformed Method is started.
Fire fighters go the the right house and save the 3 year old. Code in actionPerformed is run. The string in e.getActionCommand is used to determine the code to run.
Print Hi in the status bar in this instance.		 public void actionPerformed (ActionEvent e)
{
if (e.getActionCommand ().equals ("Hi"))
{showStatus("Hi");
}