JavaBean中的Bound属性
当一个Bound的属性的值发生了变化的时候，通知其他对象。
例子为Bound的属性发生变化，通知listen，最后又listen.jsp显示出来。
1.首先建立JavaBean，类文件名为Bound.java，代码如下：
package com.vote.bean;
import java.beans.*;
public class Bound {
private String name;
private PropertyChangeSupport support = new
PropertyChangeSupport(this);
public Bound(){
}
public void
addPropertyChangeListener(PropertyChangeListener listener){
if(support==null){
support=new
PropertyChangeSupport(this);
}
support.addPropertyChangeListener(listener);
}
public void
removePropertyChangeListener(PropertyChangeListener
listener){
if(support==null){
support=new
PropertyChangeSupport(this);
}
support.removePropertyChangeListener(listener);
}
public String getName() {
return name;
}
public void setName(String name) {
String tmp = this.name;
this.name = name;
support.firePropertyChange("name",
tmp, name);
}
}
2.监听者为Listen.java类，代码如下：
package com.vote.bean;
import java.beans.*;
public class Listen implements PropertyChangeListener{
private String inform;
public Listen() {
inform="Bean中的属性值没有变化";
}
public void propertyChange(PropertyChangeEvent
evt){
inform="Bean中的属性值发生了变化";
}
public String getInform(){
return inform;
}
}
3.显示的页面为listen.jsp，代码如下：
<%@ page language="java" import="java.util.*"
pageEncoding="utf-8"%>
<%@ page import ="com.vote.bean.Bound"
%>
<%@ page import ="com.vote.bean.Listen"
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01
Transitional//EN">
<html>
<head>
<title>Bound属性测试</title>
<meta http-equiv="pragma"
content="no-cache">
<meta http-equiv="cache-control"
content="no-cache">
<meta http-equiv="expires"
content="0">
<meta http-equiv="keywords"
content="keyword1,keyword2,keyword3">
<meta http-equiv="description"
content="This is my page">
<!--
<link rel="stylesheet"
type="text/css" href="styles.css">
-->
</head>
<body><br>
<%
Bound
bound=new Bound();
Listen
listen = new Listen();
bound.setName("张三");
%>
<p>
<b>name=<%=bound.getName()
%></b>
</p>
<%
bound.addPropertyChangeListener(listen);
bound.setName("李四");
%>
<hr><%=listen.getInform()
%>
<hr>name=<%=bound.getName()
%>
</body>
</html>
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