526互联

day101-HttpServletResponse实现重定向

发布时间 2023-03-22 21:08:47作者: 北海之上

HttpServletResponse实现重定向

一个web资源收到客户端请求后，通知a客户访问另一个web资源，这个过程叫重定向

常见场景：用户登录

使用resp.sendRedirect请求跳转至指定的页面

 
public class RedirectServlet extends HttpServlet {
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
 //        resp.sendRedirect(req.getContextPath()+"/image");
 //        resp.setHeader("Location","image");
 //        resp.setStatus(302);
         resp.sendRedirect("image");
     }
 ​
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         doGet(req, resp);
     }
 }

 

image界面是实现验证码

测试request请求

 public class RequestTest extends HttpServlet {
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         System.out.println("进入RequestTest请求");
         //处理请求
         String username = req.getParameter("username");
         String password = req.getParameter("password");
         System.out.println(username+","+password);
         resp.sendRedirect("success.jsp");
 ​
 ​
     }
 ​
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         doGet(req, resp);
     }
 }

 

在初始界面进入index.jsp

 <html>
 <body>
 <h2>Hello World!</h2>
 ​
 <%--提交的路径是项目的路径--%>
 <form action="${pageContext.request.contextPath}/login" method="get">
     用户名：<input type="text" name="username">
     密码：<input type="text" name="pwd">
     <input type="submit">
 </form>
 <%@page contentType="text/html;" pageEncoding="UTF-8"%>
 </body>
 </html>

 

提交后跳到request的login下，使用重定向进入success.jsp

 <%@ page contentType="text/html;charset=UTF-8" language="java" %>
 <html>
 <head>
     <title>Title</title>
 </head>
 <body>
 ​
 <h1>
 欢迎进入
 </h1>
 ​
 </body>
 </html>

 

servlet定义

 
<servlet>
     <servlet-name>image</servlet-name>
     <servlet-class>com.gu.servlet.ImageServlet</servlet-class>
 </servlet>
 <servlet-mapping>
     <servlet-name>image</servlet-name>
     <url-pattern>/image</url-pattern>
 </servlet-mapping>
 ​
 <servlet>
         <servlet-name>RedirectServlet</servlet-name>
         <servlet-class>com.gu.servlet.RedirectServlet</servlet-class>
     </servlet>
     <servlet-mapping>
         <servlet-name>RedirectServlet</servlet-name>
         <url-pattern>/red</url-pattern>
     </servlet-mapping>
 ​
     <servlet>
         <servlet-name>request</servlet-name>
         <servlet-class>com.gu.servlet.RequestTest</servlet-class>
     </servlet>
     <servlet-mapping>
         <servlet-name>request</servlet-name>
         <url-pattern>/login</url-pattern>
     </servlet-mapping>