转发（forward）和重定向（redirect）

转发和重定向

参考：http://www.2cto.com/kf/201107/97118.html

以前写的一个注册页面：

 1 package com.ifly.bbs.controller;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.ServletException;
 6 import javax.servlet.annotation.WebServlet;
 7 import javax.servlet.http.HttpServlet;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10 
11 import com.ifly.bbs.pojo.User;
12 import com.ifly.bbs.service.UserService;
13 import com.ifly.bbs.service.impl.UserServiceImpl;
14 
15 @WebServlet("/ZhuCe")
16 public class ZhuceController extends HttpServlet {
17     private static final long serialVersionUID = 1L;
18 
19     protected void doGet(HttpServletRequest request,
20             HttpServletResponse response) throws ServletException, IOException {
21 
22         request.getRequestDispatcher("/WEB-INF/view/ZhuCe.jsp").forward(
23                 request, response);
24     }
25 
26     protected void doPost(HttpServletRequest request,
27             HttpServletResponse response) throws ServletException, IOException {
28 
29         // 设置编码
30         request.setCharacterEncoding("UTF-8");
31         response.setCharacterEncoding("UTF-8");
32         response.setContentType("text/html;charset=UTF-8");
33 
34         // 获取参数
35         String email = request.getParameter("email").trim();
36         String name = request.getParameter("name").trim();
37         String psw = request.getParameter("psw").trim();
38         String comfirmPsw = request.getParameter("comfirmPsw").trim();
39 
40         //注册时判断两次输入的密码是否相同
41         if (!psw.equals(comfirmPsw)) {
42             // 注册失败，保存邮箱
43             request.setAttribute("email", email);
44 
45             request.setAttribute("error", "两次密码不一致");
46             request.getRequestDispatcher("/WEB-INF/view/ZhuCe.jsp").forward(
47                     request, response);
48             return;
49         }
50 
51         // 调用service代码
52         User user = new User();
53         user.setEmail(email);
54         user.setName(name);
55         user.setPassword(psw);
56 
57         UserService us = new UserServiceImpl();
58         us.add(user);
59 
60         // 重定向
61         response.sendRedirect(request.getContextPath() + "/Login");
62 
63     }
64 
65 }