任务目标
实现监听ServletContext HttpSession ServletRequest这三个域对象的生命周期
创建监听器MyListener
public class MyListener implements
ServletContextListener, HttpSessionListener,ServletRequestListener {
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("ServletContext对象被创建了");
}
public void contextDestroyed(ServletContextEvent arg0) {
System.out.println("ServletContext对象被销毁了");
}
public void requestInitialized(ServletRequestEvent arg0) {
System.out.println("ServletRequest对象被创建了");
}
public void requestDestroyed(ServletRequestEvent arg0) {
System.out.println("ServletRequest对象被销毁了");
}
public void sessionCreated(HttpSessionEvent arg0) {
System.out.println("HttpSession对象被创建了");
}
public void sessionDestroyed(HttpSessionEvent arg0) {
System.out.println("HttpSession对象被销毁了");
}
}web.xml中配置监听器
<listener>
<listener-class>cn.itcast.chapter08.listener.MyListener</listener-class>
</listener>启动项目，查看ServletContext对象创建信息
关闭项目，查看ServletContext对象销毁信息
创建测试页面myjsp.jsp
测试HttpSessionListener,ServletRequestListener
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<html>
<head>
<title>this is MyJsp.jsp page</title>
</head>
<body>
这是一个测试监听器的页面
</body>
</html>设置session超时时间
<session-config>
<session-timeout>2</session-timeout>
</session-config>再次启动项目，查看结果
访问测试页面http://localhost:8080/chapter08/myjsp.jsp
浏览器关闭或者不刷新，两分钟后Session对象都会被销毁，所以控制台输出以下内容
