Adapt适配器

为接口提供所有的空实现，让使用者仅仅覆盖需要的部分；

本思想肯定有问题，慢慢考究

　　　　frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                // TODO Auto-generated method stub
                super.windowClosing(e);
            }
        });

Window是一个接口，拥有众多方法等等待实现，如关闭，打开，最小化。。。。

WindowAdapter()是一个适配器，提供了所有Window方法的空实现，在不覆盖时，什么也不做

public abstract class WindowAdapter
implements WindowListener, WindowStateListener, WindowFocusListener
{
public void windowOpened(WindowEvent e) {}
public void windowClosing(WindowEvent e) {}
public void windowClosed(WindowEvent e) {}
public void windowIconified(WindowEvent e) {}
public void windowDeiconified(WindowEvent e) {}
public void windowActivated(WindowEvent e) {}
public void windowDeactivated(WindowEvent e) {}
public void windowStateChanged(WindowEvent e) {}
public void windowGainedFocus(WindowEvent e) {}
public void windowLostFocus(WindowEvent e) {}
}