jsp里面实现asp.net的Global文件内容。

Global.java文件：

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletRequest;
import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

public class Global implements ServletContextListener, HttpSessionListener,
        ServletRequestListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        // TODO Auto-generated method stub
        System.out.println("网站启动");
        ServletContext application = sce.getServletContext();
        application.setAttribute("count", 10);
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        // TODO Auto-generated method stub
        ServletContext application = sce.getServletContext();
        application.setAttribute("count", 0);
        System.out.println("网站停止");
    }

    @Override
    public void requestInitialized(ServletRequestEvent arg0) {
        // TODO Auto-generated method stub
        System.out.println("服务器接收一个请求");
        ServletRequest request = arg0.getServletRequest();
        if (request instanceof HttpServletRequest) {
            HttpServletRequest httpRequest = (HttpServletRequest) request;
            String url = httpRequest.getRequestURI();
            System.out.println(url);
        }
    }

    @Override
    public void requestDestroyed(ServletRequestEvent arg0) {
        // TODO Auto-generated method stub
        System.out.println("服务器销毁一个请求");
    }

    @Override
    public void sessionCreated(HttpSessionEvent arg0) {
        // TODO Auto-generated method stub
        System.out.println("服务器创建一个会话");
        HttpSession session = arg0.getSession();
        session.setAttribute("count", 10);

        ServletContext application = session.getServletContext();
        Object obj = application.getAttribute("count");
        if (obj instanceof Integer) {
            Integer appCount = (Integer) obj;
            appCount += 1;
            application.setAttribute("count", appCount);
        }
    }

    @Override
    public void sessionDestroyed(HttpSessionEvent arg0) {
        // TODO Auto-generated method stub
        System.out.println("服务器销毁一个会话");
        HttpSession session = arg0.getSession();
        ServletContext application = session.getServletContext();
        Object obj = application.getAttribute("count");
        if (obj instanceof Integer) {
            Integer appCount = (Integer) obj;
            appCount -= 1;
            application.setAttribute("count", appCount);
        }
    }
}

web.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <listener>
  <listener-class>Global</listener-class>
 </listener>
</web-app>