Java捕获窗口焦点事件

package com.han;

import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;

import javax.swing.JFrame;

/**
 * 捕获窗口焦点事件
 * @author HAN
 *
 */
public class WindowEvent_1 extends JFrame {

  /**
   * 
   */
  private static final long serialVersionUID = 6385933774053272194L;

  public WindowEvent_1() {
    // TODO Auto-generated constructor stub
    addWindowFocusListener(new WindowFocusListener() {

      @Override
      public void windowGainedFocus(WindowEvent e) {
        // TODO Auto-generated method stub
        System.out.println("窗口获得了焦点！");
      }

      @Override
      public void windowLostFocus(WindowEvent e) {
        // TODO Auto-generated method stub
        System.out.println("窗口失去了焦点！");
      }

    });
  }

  /**
   * @param args
   */
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    WindowEvent_1 frame = new WindowEvent_1();
    frame.setTitle("捕获窗口焦点事件");
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setBounds(0, 0, 300, 100);
  }

}