The jsp session completes the login function and jspsession logs in

The jsp session completes the login function and jspsession logs in

Login. jsp:

1 <% @ page language = "java" import = "java. util. * "contentType =" text/html; charset = UTF-8 "%> 2 <% 3 String path = request. getContextPath (); 4 String basePath = request. getScheme () + ": //" + request. getServerName () + ":" + request. getServerPort () + path + "/"; 5%> 6 7 <! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN"> 8 
Welcom. jsp
1 <% @ page language = "java" import = "java. util. * "contentType =" text/html; charset = UTF-8 "%> 2 <% 3 String path = request. getContextPath (); 4 String basePath = request. getScheme () + ": //" + request. getServerName () + ":" + request. getServerPort () + path + "/"; 5%> 6 7 <! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN"> 8 
Web. xml
 1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app version="2.5"  3     xmlns="http://java.sun.com/xml/ns/javaee"  4     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  5     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee  6     http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 7   <display-name></display-name>     8   <welcome-file-list> 9     <welcome-file>index.jsp</welcome-file>10   </welcome-file-list>11   <servlet>12       <servlet-name>CheckUser</servlet-name>13       <servlet-class>servlet.CheckUser</servlet-class>14   </servlet>15   <servlet-mapping>16       <servlet-name>CheckUser</servlet-name>17       <url-pattern>/check</url-pattern>18   </servlet-mapping>19   20 </web-app>
CheckUser. java
 1 package servlet; 2  3 import java.io.IOException; 4  5 import javax.servlet.RequestDispatcher; 6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse;10 import javax.servlet.http.HttpSession;11 12 public class CheckUser extends HttpServlet {13     @Override14     protected void doPost(HttpServletRequest request,15             HttpServletResponse response) throws ServletException, IOException {16             request.setCharacterEncoding("UTF-8");17             String userId=request.getParameter("userId");18             String passwd=request.getParameter("passwd");19             20             if(userId!=null&&passwd!=null&&userId.equals("gys")&&passwd.equals("gys")){21                 HttpSession session=request.getSession();22                 session.setAttribute("user", userId);23                 RequestDispatcher dispatcher=request.getRequestDispatcher("/welcome.jsp");24                 dispatcher.forward(request, response);25             }26             else{27                 RequestDispatcher dispatcher=request.getRequestDispatcher("/login.jsp");28                 dispatcher.forward(request, response);29             }30     }31 }