JAVA Interview Questions

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class LookAndFeelDemo extends JFrame {
public LookAndFeelDemo() {
initComponents();
}

public void initComponents() {
setSize(200, 200);
setTitle("LAF Demo");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getContentPane().setLayout(new FlowLayout(FlowLayout.LEFT));

JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("Look and Feel");

final JFrame frame = this;

//
// Get all the available look and feel that we are going to use for
// creating the JMenuItem and assign the action listener to handle
// the selection of menu item to change the look and feel.
//
UIManager.LookAndFeelInfo[] lookAndFeelInfos = UIManager.getInstalledLookAndFeels();
for (int i = 0; i < lookAndFeelInfos.length; i++) {
final UIManager.LookAndFeelInfo lookAndFeelInfo = lookAndFeelInfos[i];
JMenuItem item = new JMenuItem(lookAndFeelInfo.getName());
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
//
// Set the look and feel for the frame and update the UI
// to use a new selected look and feel.
//
UIManager.setLookAndFeel(lookAndFeelInfo.getClassName());
SwingUtilities.updateComponentTreeUI(frame);
} catch (ClassNotFoundException e1) {
e1.printStackTrace();
} catch (InstantiationException e1) {
e1.printStackTrace();
} catch (IllegalAccessException e1) {
e1.printStackTrace();
} catch (UnsupportedLookAndFeelException e1) {
e1.printStackTrace();
}
}
});
menu.add(item);
}

menuBar.add(menu);

getContentPane().add(menuBar);
getContentPane().add(new JButton("Hello"));
}

public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new LookAndFeelDemo().setVisible(true);
}
});
}
}