Spring MVC 3.0 請求轉發和重定向

時間 2019-11-18

原文原文鏈接

首先看一下如何得到request對象、session對象：html

普通的Controller類，示例代碼以下：java

@Controller
@RequestMapping(value = "user")
public class UserController  {
    
    @RequestMapping(value = "/reg2")
    public String reg2(String uname,HttpServletRequest req,ModelMap map){
        req.setAttribute("a", "aa");
        req.getSession().setAttribute("b", "bb");
        return "index";
    }
}

ModelMap:web

是map的實現，能夠在其中存放屬性，做用域同request。下面這個示例，咱們能夠在modelMap中放入數據，而後在forward的頁面上顯示這些數據。spring

經過el表達式、JSTL、java代碼都可。session

代碼以下：mvc

package com.sxt.web;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.mvc.multiaction.MultiActionController;

@Controller
@RequestMapping(value = "user")
public class UserController extends MultiActionController  {
    
    @RequestMapping(value = "/reg")
    public String reg(String uname,ModelMap map){
        map.put("a", "aaa");
        return "index";
    }
}

JSP頁面：
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head></head>
  <body>
       <h1>${requestScope.a}</h1>
       <c:out value="${requestScope.a}"></c:out>
  </body>
</html>

請求轉發和重定向：app

package com.sxt.web;

import javax.annotation.Resource;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;

@Controller
@RequestMapping(value = "user")
public class UserController  {
    
    @RequestMapping(value = "/reg4")
    public String reg4(ModelMap map) {
        System.out.println("HelloController.handleRequest()");
//        return "forward:index.jsp";
//        return "forward:user.do?method=reg5"; //轉發
//        return "redirect:user.do?method=reg5";  //重定向
        return "redirect:http://www.baidu.com";  //重定向
    }
    
    @RequestMapping(value = "/reg5")
    public String reg5(@RequestParam("uname") String uname,ModelMap map) { 
        System.out.println("HelloController.handleRequest()");
        System.out.println(uname); 
        return "index";
    }
    
}