SpringMVC转发及重定向

基础环境搭建请参考SringMVC入门程序

1：springmvc-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">


    <context:component-scan base-package="com.applesnt.controller"/>

    <!-- 让Spring MVC不处理静态资源 -->
    <mvc:default-servlet-handler />

    <!--annotation-driven配置帮助我们完成处理器映射器和处理器适配器-->
    <mvc:annotation-driven />

    <!--视图解析器:DispatcherServlet给他的ModelAndView-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">

        <property name="prefix" value="/WEB-INF/jsp/"/>

        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

2：controller

com\applesnt\controller\HelloController.java

package com.applesnt.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@Controller
public class HelloController {

    /*走视图解析器转发*/
    @RequestMapping("/t1")
    public String t1(HttpServletRequest request, HttpServletResponse response, Model model){

        HttpSession session = request.getSession();

        model.addAttribute("msg","走视图解析器 sessionID = "+session.getId());

        //无视图解析器 就要写全路径
        return "hello";
    }

    /*不走视图解析器转发 关键字：forward*/
    @RequestMapping("/t5")
    public String t5(HttpServletRequest request, HttpServletResponse response, Model model){

        HttpSession session = request.getSession();

        model.addAttribute("msg","不走视图解析器 sessionID = "+session.getId());

        //无视图解析器 就要写全路径
        return "forward:/WEB-INF/jsp/hello.jsp";
    }

    /*不走视图解析器重定向 关键字：redirect*/
    @RequestMapping("/t6")
    public String t6(HttpServletRequest request, HttpServletResponse response, Model model){

        //无视图解析器 就要写全路径
        return "redirect:/index.jsp";
    }

    /*serlvet方式转发 */
    @GetMapping("/t2")
    public void t2(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        HttpSession session = request.getSession();
        request.setAttribute("msg","serlvet方式转发 sessionID = "+session.getId());
        request.getRequestDispatcher("/WEB-INF/jsp/hello.jsp").forward(request,response);
    }

    /*servlet方式输出*/
    @GetMapping("/t3")
    public void t3(HttpServletRequest request, HttpServletResponse response) throws IOException {
        HttpSession session = request.getSession();
        response.getWriter().print("servlet方式输出 sessionID = "+session.getId());
    }

    /*servlet方式重定向*/
    @GetMapping("/t4")
    public void t4(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.sendRedirect("/index.jsp");
    }
}