本文是自己学习所做笔记，欢迎转载，但请注明出处：http://blog.csdn.net/jesson20121020
在Swing的事件模型中，组件可以发起（触发）一个事件。每种事件的类型由不同的类表示，当事件被触发时，它将被一个或多个“监听器”接收，监听器负责处理事件。所以，事件发生的地方可以与事件处理的地方分离开。既然是以这种方式使用Swing组件，那么就只需要编写组件收到事件时将被调用的代码。所谓事件监听器，就是一个“实现特定类型的监听器接口”类对象。
下面，就以一个查找Swing组件里的addListener的例子来演示Swing事件模型,完整代码如下：
public class ShowAddListeners extends JFrame {
private JTextField name = new JTextField(18);
private JButton search = new JButton("查询");
private JTextArea results = new JTextArea(30,50);
//定义正则表达式匹配addListener
private static Pattern addListener = Pattern.compile("(add\\w+?Listener\\(.*?\\))");
private static Pattern qualifier = Pattern.compile("\\w+\\.");
public ShowAddListeners(){
setVisible(true);
setSize(600, 400);
JPanel top = new JPanel();
top.add(new JLabel("Swing Class name(press Enter):"));
top.add(name);
top.add(search);
add(BorderLayout.NORTH,top);
add(new JScrollPane(results));
//设置不可编辑
//results.setEditable(false);
search.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent event) {
// TODO Auto-generated method stub
//去掉关键字的前后空格
String nm = name.getText().trim();
//如果去掉关键字后长度为为，则显示没有匹配成功的
if(nm.length() == 0){
results.setText("no match!");
return;
}
Class<?> kind;
try {
kind = Class.forName("javax.swing."+nm);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
results.setText("no match!");
return;
}
Method[] methods = kind.getMethods();
results.setText("");
for(Method m : methods){
Matcher matcher = addListener.matcher(m.toString());
//如果找到了匹配的方法，则输出
if(matcher.find()){
results.append(qualifier.matcher(matcher.group(1)).replaceAll("")+"\n");
}
}
}
});
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
new ShowAddListeners();
}
} 效果：
这里面主要用到了正则表达式用于匹配相应的监听器,这里只是用到了一个监听器接收，上面也提到了，组件也可以绑定多个监听器。
下面就实现JButton的几个重要的事件监听器，分别是FocusListener、KeyListener、MouseListener和MouseMotionListener
，给按钮绑定这些监听器，当对应的事件发生时，触发相应的事件，从而执行对应的操作，完整代码如下：
public class TrackEvent extends JFrame {
private HashMap<String,JTextField> map = new HashMap<String,JTextField>();
private String[] event = {
"focusGained",
"focusLost",
"keyPressed",
"keyReleased",
"keyTyped",
"mouseClicked",
"mouseEntered",
"mouseExited",
"mousePressed",
"mouseReleased",
"mouseDragged",
"mouseMoved"
};
private MyButton b1 = new MyButton(Color.BLUE,"test1");
private MyButton b2 = new MyButton(Color.RED,"test2");
class MyButton extends JButton{
private void report(String field,String msg){
map.get(field).setText(msg);
}
private FocusListener fl = new FocusListener() {
@Override
public void focusLost(FocusEvent e) {
// TODO Auto-generated method stub
report("focusLost",e.paramString());
}
@Override
public void focusGained(FocusEvent e) {
// TODO Auto-generated method stub
report("focusGained",e.paramString());
}
};
private KeyListener kl = new KeyListener() {
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
report("keyTyped",e.paramString());
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
report("keyReleased",e.paramString());
}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
report("keyPressed",e.paramString());
}
};
private MouseListener ml = new MouseListener() {
@Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
report("mouseReleased",e.paramString());
}
@Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub
report("mousePressed",e.paramString());
}
@Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
report("mouseExited",e.paramString());
}
@Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
report("mouseEntered",e.paramString());
}
@Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
report("mouseClicked",e.paramString());
}
};
private MouseMotionListener mml = new MouseMotionListener() {
@Override
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
report("mouseMoved",e.paramString());
}
@Override
public void mouseDragged(MouseEvent e) {
// TODO Auto-generated method stub
report("mouseDragged",e.paramString());
}
};
public MyButton(Color color,String label) {
super(label);
setBackground(color);
addFocusListener(fl);
addKeyListener(kl);
addMouseListener(ml);
addMouseMotionListener(mml);
}
}
public TrackEvent() {
// TODO Auto-generated constructor stub
setLayout(new GridLayout(event.length + 1,2));
for(String evt : event){
JTextField tf = new JTextField();
tf.setEditable(false);
add(new JLabel(evt,JLabel.RIGHT ));
add(tf);
setSize(700,500);
setVisible(true);
map.put(evt, tf);
}
add(b1);
add(b2);
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
new TrackEvent();
}
});
}
} 执行结果：
这样，鼠标单击按钮，拖动按钮，移动按钮等事件发生时，就会触发相应的监听器，从而将事件的动作以字符串的形式显示在JTextField中，即组件跟踪多个事件。
原文地址：http://blog.csdn.net/jesson20121020/article/details/41123217
