EXIT_ON_CLOSE：结束窗口所在的应用程序。在窗口被关闭的时候会退出JVM。
DISPOSE_ON_CLOSE：隐藏当前窗口，并释放此窗体占有的资源。如果程序没有其他线程在运行，当所有窗口都被dispose后，JVM也会退出。
举例说明：关闭窗体A，窗体B也会退出。关闭窗体B，窗体A不会退出。
public class Demo{
public static void main(String[] args){
JFrame window1=new JFrame("窗体A");
JFrame window2=new JFrame("窗体B");
window1.setBounds(100,100,200,100);
window2.setBounds(400,100,200,100);
window1.setVisible(true);
window2.setVisible(true);
window1.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
window2.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
}
}
【窗体监听事件 WindowListener】windowOpened 打开windowActivated 激活（获得焦点状态）windowDeactivated 非激活（失去焦点状态）windowIconified 最小化windowDeiconified 最小化恢复正常windowClosing 关闭（右上角X），优先于windowClosedwindowClosed 关闭，DISPOSE_ON_CLOSE时才会被调用
public class Demo extends JFrame {
public Demo() {
setBounds(100, 100, 300, 300);
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
setVisible(true);
addWindowListener(new MyWindowListener());//调用方法类对象
}
class MyWindowListener implements WindowListener {
public void windowOpened(WindowEvent e) {
System.out.println("窗体打开");
}
public void windowClosing(WindowEvent e) {
System.out.println("窗体关闭exit");
}
public void windowClosed(WindowEvent e) {
System.out.println("窗体关闭dispose");
}
public void windowIconified(WindowEvent e) {
System.out.println("窗体最小化");
}
public void windowDeiconified(WindowEvent e) {
System.out.println("窗体最小化恢复正常");
}
public void windowActivated(WindowEvent e) {
System.out.println("窗体激活");
}
public void windowDeactivated(WindowEvent e) {
System.out.println("窗体非激活");
}
}
public static void main(String[] args) {
new Demo();
}
}