import java.awt.*; import javax.swing.*; import javax.swing.event.*; class JTabbedPaneTest extends JFrame implements ChangeListener { JTree tree = new JTree(); JTable table = new JTable(3, 3); JTabbedPaneTest() { JTabbedPane tabbedPane = new JTabbedPane(); tabbedPane.add("AAA", tree); tabbedPane.add("BBB", table); tabbedPane.addChangeListener(this); getContentPane().add(tabbedPane); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setTitle("JTabbedPaneTest"); setSize(200, 150); setVisible(true); } public void stateChanged(ChangeEvent e) { JTabbedPane t = (JTabbedPane)e.getSource(); if (t.getSelectedComponent() == tree) { System.out.println("Tree"); } else { System.out.println("Table"); } } public static void main(String args[]) { new JTabbedPaneTest(); } }