Check the event source in actionPerformed method : ActionListener « Swing Event « Java Tutorial

1. Java Tutorial
2. Swing Event
3. ActionListener

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class MainClass extends JFrame implements ActionListener {
  private JButton button1 = new JButton("Click Me!");
  private int clickCount = 0;  
  public static void main(String[] args) {
    new MainClass();
  }
  public MainClass() {
    this.setSize(200, 100);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setTitle("I'm Listening");

    JPanel panel1 = new JPanel();
    button1.addActionListener(this);
    panel1.add(button1);
    this.add(panel1);

    this.setVisible(true);
  }
  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == button1) {
      clickCount++;
      if (clickCount == 1)
        button1.setText("I've been clicked!");
      else
        button1.setText("I've been clicked" + clickCount + " times!");
    }
  }
}

15.5.ActionListener
	15.5.1.	implements ActionListener and action class level variable
	15.5.2.	Handling an action listener
	15.5.3.	Check the event source in actionPerformed method
	15.5.4.	Use an Inner Class to handle the event
	15.5.5.	Use one inner class to handle events from two buttons
	15.5.6.	Get event source from ActionEvent
	15.5.7.	Add action listener to JTextField
	15.5.8.	ComboBox with ActionListener
	15.5.9.	ActionEvent.getActionCommand()
	15.5.10.	Using an inner ActionListener class.