We can implement a MouseListener interface when the mouse is stable while handling the mouse event. A MouseEvent is fired when we can press, release or click (press followed by release) a mouse button (left or right button) at the source object or position the mouse pointer at (enter) and away (exit) from the source object. We can detect a mouse event when the mouse moves over any component such as a label by using the mouseEntered() method and can be exited by using mouseExited() method of MouseAdapter class or MouseListener interface.
Example
import java.awt.*; import java.awt.event.*; import javax.swing.*; public class MouseOverTest extends JFrame { private JLabel label; public MouseOverTest() { setTitle("MouseOver Test"); setLayout(new FlowLayout()); label = new JLabel("Move the mouse moves over this JLabel"); label.setOpaque(true); add(label); label.addMouseListener(new MouseAdapter() { public void mouseEntered(MouseEvent evt) { Color c = label.getBackground(); // When the mouse moves over a label, the background color changed. label.setBackground(label.getForeground()); label.setForeground(c); } public void mouseExited(MouseEvent evt) { Color c = label.getBackground(); label.setBackground(label.getForeground()); label.setForeground(c); } }); setSize(400, 275); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setLocationRelativeTo(null); setVisible(true); } public static void main(String[] args) { new MouseOverTest(); } }