JavaWeb URL重写和会话跟踪

package com.xzit.servlet;

import java.io.IOException;

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;

/**
 * Servlet implementation class UrlRewriteServlet
 */
@WebServlet("/servlet/UrlRewriteServlet")
public class UrlRewriteServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
     */
    protected void service(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
        String name = request.getParameter("username");
        String pwd = request.getParameter("password");
             
        if(name.equals("admin") && pwd.equals("111111")) {
            
            HttpSession session =  request.getSession();
            session.setAttribute("username", name);
            String sessId = session.getId();    //获取会话的唯一标识
            System.out.println("当前会话的id:"+sessId);
            String newUrl = "welcome.jsp";    //被重写的url
            String rewriteUrl =  response.encodeRedirectURL(newUrl);
            /* 获取当前应用程序的部署发布url全名称 */
            String http = request.getScheme();
            String ip = request.getServerName();
            int port = request.getServerPort();
            String path = request.getContextPath();
            
            String contextFullPath = http+"://"+ip+":"+port+path+"/";
            System.out.println("发布应用程序全名称："+contextFullPath);
            //request.getRequestDispatcher(contextFullPath+rewriteUrl).forward(request, response);
            response.sendRedirect(contextFullPath+"jsp/"+rewriteUrl);
        }else {
            
            response.sendRedirect("index.jsp?message=failed&info=login failed");
        }
        
    }

}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>



    
    

    
        

            用户名称：

            用户密码：

            用户名称：

        
        <%
            String m = request.getParameter("message");
            String info = request.getParameter("info");
            
            if(m != null && m.equals("failed")){
                
                %>
                
                 系统提示：<%=info %>
            <%}
        %>
    

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>



    
    

    
        当前用户名称：${sessionScope.username}
    

<?xml version="1.0" encoding="UTF-8"?>
 
xmlns="http://xmlns.jcp.org/xml/ns/javaee" 
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" 
id="WebApp_ID" version="3.1">
  UrlRewrite
  
  
      5
  
  




  




  
  
    index.jsp