首先，什么是监听器？
监听器主要有以下几种：
现在，我们来一一试过，把所有的事件监听器全部写好，按照输出，我们来分析：
首先是：ServletContextEvent事件：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
public class Listenerapplication implements ServletContextListener{
@Override
public void contextDestroyed(ServletContextEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"application结束");
System.out.println();
System.out.println();
}
@Override
public void contextInitialized(ServletContextEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"application开始");
System.out.println();
System.out.println();
}
}
接下来是
ServletContextAttributeEvent:
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.ServletContextAttributeEvent;
import javax.servlet.ServletContextAttributeListener;
public class Listernerapplicationattr implements ServletContextAttributeListener{
@Override
public void attributeAdded(ServletContextAttributeEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"application的属性被新建"+arg0.getName());
System.out.println();
System.out.println();
}
@Override
public void attributeRemoved(ServletContextAttributeEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdFormat.format(new Date())+"application的"+arg0.getName()+"属性被删除");
System.out.println();
System.out.println();
}
@Override
public void attributeReplaced(ServletContextAttributeEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"application的"+arg0.getName()+"属性值被修改为:"+arg0.getValue());
System.out.println();
System.out.println();
}
}
HttpSessionEvent事件的HttpSessionListener接口：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
public class Listenersession implements HttpSessionListener{
@Override
public void sessionCreated(HttpSessionEvent se) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date()) + "session对象被创建" + se.getSession());
System.out.println();
System.out.println();
}
@Override
public void sessionDestroyed(HttpSessionEvent se) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"session对象被销毁" + se.getSource()+se.getClass());
System.out.println();
System.out.println();
}
}
HttpSessionEvent事件的HttpSessionActivationListener接口：
这个接口并不是直接监听的，而是依附于具体的实体类对象中，即由具体需要的实体类进行实现这个接口，实现这个接口所定义的方法，这样，当在使用到这个实体类的对象时，就会触发这个监听器，从而执行对应的方法：
首先，我们现在实体类中实现这个接口：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.http.HttpSessionActivationListener;
import javax.servlet.http.HttpSessionEvent;
public class Man implements HttpSessionActivationListener{
@Override
public void sessionDidActivate(HttpSessionEvent se) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date()) +"这是session的didActive方法");
System.out.println();
System.out.println();
}
@Override
public void sessionWillPassivate(HttpSessionEvent se) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"这是session的Willpassivate方法");
System.out.println();
System.out.println();
}
public Man() {
super();
// TODO Auto-generated constructor stub
}
}
接下来，我们重写一个测试页面：
<%@page import="java.text.SimpleDateFormat"%>
<%@page import="com.xust.jia.listener.Man"%>
<%@page import="java.util.Date" %>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>这是测试session的activationListener接口</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>
<h1>测试session的activationListener接口</h1>
<%
if(session.getAttribute("act") == null)
{
Man man = new Man();
session.setAttribute("act", man);
}
System.out.println(session.getId()+session.getAttribute("act"));
Date d = new Date(session.getCreationTime());
System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(d));
%>
</body>
</html>
然后，在对服务器进行配置：
其中，htmlday1是项目名称，然后，在里面写入：
接下来，我们先打开配置的xml,然后通过xml来访问测试页面进行测试：
说明这个测试页面里的语句被执行，然后关闭服务器，重新打开服务器,发现在E:盘下多了一个文件夹，a:
发现多了一个SESSION文件，打开如下：
在控制台输出以下信息：
注意，关闭服务器是正常关闭，不是直接关闭。
HttpSessionBindingEvent事件的HttpSessionAttributeListener接口：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.http.HttpSessionAttributeListener;
import javax.servlet.http.HttpSessionBindingEvent;
public class Listenersessionattr implements HttpSessionAttributeListener{
@Override
public void attributeAdded(HttpSessionBindingEvent event) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"session的"+event.getName()+"属性被增加,值为:"+event.getValue());
System.out.println();
System.out.println();
}
@Override
public void attributeRemoved(HttpSessionBindingEvent event) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"session的"+event.getName()+"属性被删除，值为:"+event.getValue());
System.out.println();
System.out.println();
}
@Override
public void attributeReplaced(HttpSessionBindingEvent event) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"session的"+event.getName()+"属性值被修改为:"+event.getValue());
System.out.println();
System.out.println();
}
}
HttpSessionBindingEvent事件的HttpSessionBindingListener接口：
因为这个接口比较特殊，是在实体类中进行实现方法，而且不需要在Web.xml文件中进行配置，所以，我们只是简单的检测验证一下这个接口：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
public class Person implements HttpSessionBindingListener{
@Override
public void valueBound(HttpSessionBindingEvent event) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"这是Binding的Bound"+event.getName()+event.getValue());
System.out.println();
System.out.println();
}
@Override
public void valueUnbound(HttpSessionBindingEvent event) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"这是Binding的Unbound"+event.getName()+event.getValue());
System.out.println();
System.out.println();
}
public Person() {
super();
// TODO Auto-generated constructor stub
}
}
接下来，我们在servlet类中进行调用这个类，然后把这个类对象加载到会话的属性中，最后使用session的方法，销毁这个session：
在servlet的post或者get方法中写入如下代码：
Person person = new Person();
HttpSession hsHttpSession = request.getSession();
hsHttpSession.setAttribute("person", person);
hsHttpSession.invalidate();
接下来，我们调入这个servlet方法中，进行测试：
显示结果如下：
ServletRequestEvent事件：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;
public class Listenerrequest implements ServletRequestListener{
@Override
public void requestDestroyed(ServletRequestEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"request被创建");
System.out.println();
System.out.println();
}
@Override
public void requestInitialized(ServletRequestEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"request被销毁");
System.out.println();
System.out.println();
}
}
ServletRequestAttributeEvent事件：
package com.xust.jia.listener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.ServletRequestAttributeEvent;
import javax.servlet.ServletRequestAttributeListener;
public class Listenerrequestattr implements ServletRequestAttributeListener{
@Override
public void attributeAdded(ServletRequestAttributeEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"request的"+arg0.getName()+"属性被创建，值为:"+arg0.getValue());
System.out.println();
System.out.println();
}
@Override
public void attributeRemoved(ServletRequestAttributeEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"request的"+arg0.getName()+"属性被删除，值为:"+arg0.getValue());
System.out.println();
System.out.println();
}
@Override
public void attributeReplaced(ServletRequestAttributeEvent arg0) {
// TODO Auto-generated method stub
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println();
System.out.println();
System.out.println(sdf.format(new Date())+"request的"+arg0.getName()+"属性被修改，值为:"+arg0.getValue());
System.out.println();
System.out.println();
}
}
接下来，我们写一个测试页面：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>secondjsp page</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="../CSS/index.css">
<script type="text/javascript" src="./js/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function() {
$("#div").hide();
$("#button").click(function() {
$("#div").show();
});
});
</script>
</head>
<body>
<%
String nameString = "小李子";
String pswdString = "1234567";
String sexString = "男";
String ageString = "21";
/* String nmString = request.getParameter("user");
String pdString = request.getParameter("pswd");
String sString = request.getParameter("sex");
String aString = request.getParameter("age"); */
/* nameString = new String(nmString.getBytes("ISO-8859-1"), "UTF-8");
pswdString = new String(pdString.getBytes("ISO-8859-1"), "UTF-8");
sexString = new String(sString.getBytes("ISO-8859-1"), "UTF-8");
ageString = new String(aString.getBytes("ISO-8859-1"), "UTF-8"); */
session.setAttribute("name", nameString);
session.setAttribute("pswd", pswdString);
session.setAttribute("sex", sexString);
session.setAttribute("age", ageString);
request.setAttribute("name", nameString);
request.setAttribute("pswd", pswdString);
request.setAttribute("sex", sexString);
request.setAttribute("age", ageString);
pageContext.setAttribute("name", nameString);
pageContext.setAttribute("pswd", pswdString);
pageContext.setAttribute("sex", sexString);
pageContext.setAttribute("age", ageString);
application.setAttribute("name", nameString);
application.setAttribute("pswd", pswdString);
application.setAttribute("sex", sexString);
application.setAttribute("age", ageString);
application.setAttribute("name", "123");
application.setAttribute("pswd", "456");
application.setAttribute("sex", "女");
application.setAttribute("age", "25");
request.setAttribute("name", "123");
request.setAttribute("pswd", "456");
request.setAttribute("sex", "女");
request.setAttribute("age", "25");
session.setAttribute("name", "123");
session.setAttribute("pswd", "456");
session.setAttribute("sex", "女");
session.setAttribute("age", "25");
String namepageContextString = (String) pageContext.getAttribute("name");
String namesessionString = (String) session.getAttribute("name");
String namerequestString = (String) request.getAttribute("name");
String nameapplicationString = (String) application.getAttribute("name");
String pswdpageContextString = (String) pageContext.getAttribute("pswd");
String pswdsessionString = (String) session.getAttribute("pswd");
String pswdrequestString = (String) request.getAttribute("pswd");
String pswdapplicationString = (String) application.getAttribute("pswd");
String sexpageContextString = (String) pageContext.getAttribute("sex");
String sexsessionString = (String) session.getAttribute("sex");
String sexrequestString = (String) request.getAttribute("sex");
String sexapplicationString = (String) application.getAttribute("sex");
String agepageContextString = (String) pageContext.getAttribute("age");
String agesessionString = (String) session.getAttribute("age");
String agerequestString = (String) request.getAttribute("age");
String ageapplicationString = (String) application.getAttribute("age");
%>
<div align="center">
<button id="button">点击进行pageContext测试</button>
<br> <a href="JSP/four.jsp">点击进行session测试</a><br> <b>进行application测试:重启浏览器，并转到此链接：http://localhost:8080/htmlday1/JSP/four.jsp</b>
</div>
<div align="center" id="div"
style="font-family: 楷体;font-size: 25px;color: green;">
客户信息：<br> pageContext:<br> 姓名：<%=namepageContextString%><br>
密码：<%=pswdpageContextString%><br> 性别：<%=sexpageContextString%><br>
年龄：<%=agepageContextString%><br> session:<br> 姓名：<%=namesessionString%><br>
密码：<%=pswdsessionString%><br> 性别：<%=sexsessionString%><br>
年龄：<%=agesessionString%><br> request:<br> 姓名：<%=namerequestString%><br>
密码：<%=pswdrequestString%><br> 性别：<%=sexrequestString%><br>
年龄：<%=agerequestString%><br> application:<br> 姓名：<%=nameapplicationString%><br>
密码：<%=pswdapplicationString%><br> 性别：<%=sexapplicationString%><br>
年龄：<%=ageapplicationString%><br> <a href="JSP/Login.jsp">回到信息输入界面</a>
</div>
</body>
</html>
在这个页面中，我们对request,pageContext,session,application的属性进行设置，修改。
其次还有一个页面，可以帮助我们完成测试：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>fourjsp page</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>
<%
String namepageContextString = (String)pageContext.getAttribute("name");
String namesessionString = (String)session.getAttribute("name");
String namerequestString = (String)request.getAttribute("name");
String nameapplicationString = (String)application.getAttribute("name");
String pswdpageContextString = (String)pageContext.getAttribute("pswd");
String pswdsessionString = (String)session.getAttribute("pswd");
String pswdrequestString = (String)request.getAttribute("pswd");
String pswdapplicationString = (String)application.getAttribute("pswd");
String sexpageContextString = (String)pageContext.getAttribute("sex");
String sexsessionString = (String)session.getAttribute("sex");
String sexrequestString = (String)request.getAttribute("sex");
String sexapplicationString = (String)application.getAttribute("sex");
String agepageContextString = (String)pageContext.getAttribute("age");
String agesessionString = (String)session.getAttribute("age");
String agerequestString = (String)request.getAttribute("age");
String ageapplicationString = (String)application.getAttribute("age");
%>
客户信息：<br>
pageContext:<br>
姓名：<%=namepageContextString %><br>
密码：<%=pswdpageContextString %><br>
性别：<%=sexpageContextString %><br>
年龄：<%=agepageContextString %><br>
session:<br>
姓名：<%=namesessionString %><br>
密码：<%=pswdsessionString %><br>
性别：<%=sexsessionString %><br>
年龄：<%=agesessionString %><br>
request:<br>
姓名：<%=namerequestString %><br>
密码：<%=pswdrequestString %><br>
性别：<%=sexrequestString %><br>
年龄：<%=agerequestString %><br>
application:<br>
姓名：<%=nameapplicationString %><br>
密码：<%=pswdapplicationString %><br>
性别：<%=sexapplicationString %><br>
年龄：<%=ageapplicationString %><br>
</body>
</html>
接下来：
因为session并不会在关闭浏览器的时候，及时的销毁session对象，所以，我们在web.xml中进行设置自动销毁时间：
<session-config>
<session-timeout>1</session-timeout>
</session-config>
然后启动项目，对这些事件进行监听：
当服务器开始启动时，就会创建一个application对象，然后服务器对application对象的属性进行操作：
为什么会有一个request对象被销毁呢？
因为浏览器打开有一个首页，但是我们需要浏览器跳转到指定的页面，所以手动的修改了url地址，只要url的地址发生改变，那么，就会产生一个request请求，那么就会有一个request请求被销毁。
因为我们新打开一个浏览器，所以就产生一个新的会话，就会创建一个新的session对象，当我们打开测试的页面时，因为在测试页面里对session，application等进行属性设置，修改，所以：
因为在jsp内部引入了jQuery文件，所以会发生request对象的销毁与新建：
这里是因为，我们设置了session的自动销毁时间是1分钟，所以当超过一分钟的时候，会自动的销毁session，此时如果刷新页面，则会：
到了这里，我们，对3大对象，6个事件八个接口进行了测试，可以检测到application创建销毁的接口，application属性改变的接口,request创建销毁的接口,request属性改变的接口，session创建销毁的接口，session属性改变的接口，以及session的active和Binding的接口事件。
所以，3大对象6种事件8个接口，到了这里就测试完毕了。
