✔ JFrame sperren oder neuen JFrame modal darstellen

 package de.tutorials;
 
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
 
 import javax.swing.JButton;
 import javax.swing.JFrame;
 
 public class ModalJFrameExample extends JFrame{
 
 	public ModalJFrameExample(){
 		super("ModalJFrameExample");
 		setDefaultCloseOperation(EXIT_ON_CLOSE);
 		
 		final JButton btnNewFrame = new JButton("New Frame");
 		btnNewFrame.addActionListener(new ActionListener(){
 			public void actionPerformed(ActionEvent e) {
 				setEnabled(false);
 				JFrame frame = new JFrame("New Frame");
 				frame.addWindowListener(new WindowAdapter(){
 		    		public void windowClosing(WindowEvent e) {
 		    		    setEnabled(true);		
 					}
 				});
 				frame.setAlwaysOnTop(true);
 				frame.setVisible(true);
 			}
 		});
 		add(btnNewFrame);
 		
 		pack();
 		setVisible(true);
 	}
 	
 	/**
 	 * @param args
 	 */
 	public static void main(String[] args) {
 		new ModalJFrameExample();
 	}
 }