请问下各位，如何用内部类做监视器？

import java.awt.*;import java.awt.event.*;public class Test {    public static void main(String args[]) {        new Win();    }}class Win extends Frame {    Button button;    TextField textf;    TextArea texta;    MouseL ml;    Win() {        setLayout(new FlowLayout());        button = new Button("Button");        textf = new TextField(8);        texta = new TextArea();        button.addMouseListener(ml);        textf.addMouseListener(ml);        texta.addMouseListener(ml);        add(button);        add(textf);        add(texta);        addWindowListener(new WindowAdapter() {            public void windowClosing(WindowEvent e) {                System.exit(0);            }        });        pack();        setVisible(true);        validate();    }}class MouseL extends MouseAdapter {    Win win;    public MouseL(Win win) {        this.win = win;    }        public void mousePressed(MouseEvent e) {        /*        if(e.getSource() == win.button) {            win.texta.append("mouse clicked on Button. Position: " + "(" + e.getX() + "," + e.getY() + ").");        }        if(e.getSource() == win.textf) {            win.texta.append("mouse clicked on TextField. Position: " + "(" + e.getX() + "," + e.getY() + ").");        }        if(e.getSource() == win.texta) {            win.texta.append("mouse clicked on TextArea. Position: " + "(" + e.getX() + "," + e.getY() + ").");        }        */        System.out.println(e.getSource());    }}

addWindowListener(new WindowAdapter() {            public void windowClosing(WindowEvent e) {                System.exit(0);            }        });
------解决方案--------------------
参看http://blog.csdn.net/gaowen_han/article/details/7170918以及http://blog.csdn.net/gaowen_han/article/details/7163755里面讲得很详细