Servlet 会话管理实例

1、获取Session(如果没有session，则会自动创建一个)

request.getSession();

2、获取session创建时间

Date createTime = new Date(session.getCreationTime());

3、获取最后访问时间

 Date lastAccessTime = new Date(session.getLastAccessedTime());

4、设置attribute（键值对形式）

 session.setAttribute(Key, value);

5、获取attribute

session.getAttribute(Key);

6、获取session id

session.getId();

7、日期格式

 SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

df.format(Date);

package com.masorl;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.Date;@WebServlet("/SessionDemo")public class SessionDemo extends HttpServlet{    @Override    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//        如果没有Session，getSession会创建一个session对象        HttpSession session = req.getSession(true);//        获取session创建时间        Date createTime = new Date(session.getCreationTime());//        获取该网页的最后一次访问时间        Date lastAccessTime = new Date(session.getLastAccessedTime());//        设置日期输出的格式        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");        int visitCount = 1;        String visitCountKey = "visitCount";        String userIDKey = "userID";        String userID = "lee";        if(session.isNew()){            session.setAttribute(userIDKey, userID);        }else{            visitCount = (Integer)session.getAttribute(visitCountKey);            visitCount = visitCount + 1;            userID = (String)session.getAttribute(userIDKey);        }        session.setAttribute(visitCountKey,visitCount);        System.out.println("访问时间:  " + df.format(createTime));        System.out.println("最后访问时间:  " + df.format(lastAccessTime));        System.out.println( "id:  " + session.getId());        System.out.println("用户id:  " + userID);        System.out.println("访问次数:  " + visitCount);    }    @Override    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        doGet(req, resp);    }}