Java tutorial
import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; public class HtmlToolTipDemo extends JPanel { public static void main(String[] a) { JFrame mainFrame = new JFrame(); JLabel label = new JLabel("label"); label.setToolTipText("<html>First line<br>Second Line</html>"); mainFrame.getContentPane().add(label); mainFrame.setSize(100, 100); mainFrame.setVisible(true); } }