How to implement a rollover effect for a JButton in Java?

A JButton is a subclass of AbstractButton and it can be used for adding platform-independent buttons to a GUI application. A JButon can generate an ActionListener interface when the button is pressed or clicked, it can also generate the MouseListener and KeyListener interfaces. We can implement the rollover effect when the mouse moves over a JButton by overriding the mouseEntered() method of the MouseListener interface.

Syntax

void mouseEntered(MouseEvent e)

Example

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class RollOverButtonTest extends JFrame {
   private JButton button;
   public RollOverButtonTest() {
      setTitle("RollOverButton Test");
      button = new JButton("Rollover Button");
      button.addMouseListener(new MouseAdapter() {
         Color color = button.getForeground();
         public void mouseEntered(MouseEvent me) {
            color = button.getForeground();
            button.setForeground(Color.green); // change the color to green when mouse over a button
         }
         public void mouseExited(MouseEvent me) {
            button.setForeground(color);
         }
      });
      add(button, BorderLayout.NORTH);
      setSize(400, 300);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setLocationRelativeTo(null);
      setVisible(true);
   }
   public static void main(String[] args) {
      new RollOverButtonTest();
   }
}

Output