import java.awt.*;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

public class MultiListener extends Applet implements ActionListener {

    TextArea topTextArea;

    TextArea bottomTextArea;

    Button button1, button2;

    public void init() {

       Label l = null;

        GridBagLayout gridbag = new GridBagLayout();

        GridBagConstraints c = new GridBagConstraints();

        setLayout(gridbag);

        c.fill = GridBagConstraints.BOTH;

        c.gridwidth = GridBagConstraints.REMAINDER;

       l = new Label("What MultiListener hears:");

        gridbag.setConstraints(l, c);

        add(l);

        c.weighty = 1.0;

        topTextArea = new TextArea(5, 20);

        topTextArea.setEditable(false);

        gridbag.setConstraints(topTextArea, c);

        add(topTextArea);

        c.weightx = 0.0;

        c.weighty = 0.0;

       l = new Label("What Eavesdropper hears:");

        gridbag.setConstraints(l, c);

        add(l);

        c.weighty = 1.0;

        bottomTextArea = new TextArea(5, 20);

        bottomTextArea.setEditable(false);

        gridbag.setConstraints(bottomTextArea, c);

        add(bottomTextArea);

        c.weightx = 1.0;

        c.weighty = 0.0;

        c.gridwidth = 1;

        c.insets = new Insets(10, 10, 0, 10);

        button1 = new Button("Blah blah blah");

        gridbag.setConstraints(button1, c);

        add(button1);

        c.gridwidth = GridBagConstraints.REMAINDER;

        button2 = new Button("You don't say!");

        gridbag.setConstraints(button2, c);

        add(button2);

        button1.addActionListener(this);

        button2.addActionListener(this);

        button2.addActionListener(new Eavesdropper(bottomTextArea));

    }

    public void actionPerformed(ActionEvent e) {

        topTextArea.append(e.getActionCommand() + "\n");

    }

}

class Eavesdropper implements ActionListener {

    TextArea myTextArea;

    public Eavesdropper(TextArea ta) {

        myTextArea = ta;

    }

    public void actionPerformed(ActionEvent e) {

        myTextArea.append(e.getActionCommand() + "\n");

    }

}


在这里先是使用了一个复杂的布局管理器，真BT，把简单问题复杂化。然后给 button1 和 button2 分别加上了实现 ActionListener 的自身。并且动过 e.getActionCommand() 来获取命令文本，这里当然就是按钮上的文本了。并把该文本赋给了位于顶层的 TextArea ，然后又给 button2 注册了一个实现 ActionListener 接口的 Eavesdropper，并给他的构造函数传递了一个保存了下边的 TextArea 对象，并使用该对象来获取事件源的文本。总体来说这个例子还是可以的，就是开始复杂了些。

最后是一个鼠标事件的例子，比较简单，不罗嗦。^_^

import java.awt.*;

public class BlankArea extends Canvas {

    Dimension minSize = new Dimension(100, 100);

    public BlankArea(Color color) {

        setBackground(color);

    }

    public Dimension getMinimumSize() {

        return minSize;

    }

    public Dimension getPreferredSize() {

        return minSize;

    }

    public void paint(Graphics g) {

        Dimension size = getSize();

        g.drawRect(0, 0, size.width - 1, size.height - 1);

    }

}

import java.applet.Applet;

import java.awt.*;

import java.awt.event.MouseListener;

import java.awt.event.MouseEvent;

public class MouseEventDemo extends Applet implements MouseListener {

    BlankArea blankArea;

    TextArea textArea;

    static final int maxInt = java.lang.Integer.MAX_VALUE;

    String newline;

    public void init() {

        GridBagLayout gridbag = new GridBagLayout();

        GridBagConstraints c = new GridBagConstraints();

        setLayout(gridbag);

        c.fill = GridBagConstraints.BOTH;

        c.gridwidth = GridBagConstraints.REMAINDER;

        c.weightx = 1.0;

        c.weighty = 1.0;

        c.insets = new Insets(1, 1, 1, 1);

        blankArea = new BlankArea(new Color(0.98f, 0.97f, 0.85f));

        gridbag.setConstraints(blankArea, c);

        add(blankArea);

        c.insets = new Insets(0, 0, 0, 0);

        textArea = new TextArea(5, 20);

        textArea.setEditable(false);

        gridbag.setConstraints(textArea, c);

        add(textArea);

        //Register for mouse events on blankArea and applet (panel).

        blankArea.addMouseListener(this);

        addMouseListener(this);

        newline = System.getProperty("line.separator");

    }

    public void mousePressed(MouseEvent e) {

        saySomething("Mouse pressed; # of clicks: " + e.getClickCount(), e);

    }

    public void mouseReleased(MouseEvent e) {

        saySomething("Mouse released; # of clicks: " + e.getClickCount(), e);

    }

    public void mouseEntered(MouseEvent e) {

        saySomething("Mouse entered", e);

    }

    public void mouseExited(MouseEvent e) {

        saySomething("Mouse exited", e);

    }

    public void mouseClicked(MouseEvent e) {

        saySomething("Mouse clicked (# of clicks: " + e.getClickCount() + ")", e);

    }

    void saySomething(String eventDescription, MouseEvent e) {

        textArea.append(

           eventDescription

               + " detected on "

               + e.getComponent().getClass().getName()

               + newline);

        textArea.setCaretPosition(maxInt); //hack to scroll to bottom

    }

}