springMVC 重定向和转发

承接之前的视图解析器的内容：

是把固定的内容分离 留下可改动的部分

spring MVC也可以使用servlet里的重定向和转发。

ServletAPI
通过设置ServletAPI，不需要视图解析器.
1.通过HttpServletResponse进行输出
2.通过HttpServletResponse实现重定向
3.通过HttpServletResponse实现转发

@controller
public class ResultGo {
@RequestMapping(" /result/t1")
public void test1 (HttpservletRequest req，HttpServletResponse rsp) throws IOExcept
rsp.getwriter().println( "Hello, Spring BY servlet API");
}
@RequestMapping(" /result/t2")
public void test2(HttpServletRequest req，HttpservletResponse rsp) throws IOExcept
{
rsp.sendRedirect( "/index.jsp" );
}
@RequestMapping("/result/t3")
public void test3 (HttpServletRequest req,HttpServletResponse rsp) throws Exceptic{
req.setAttribute( "msg","/result/t3"):
req.getRequestDispatcher("/WEB-INF/jsp/test.jsp").forward(req,rsp);
}

session会话：

    @RequestMapping("/session")
    public String test1(HttpServletRequest req,HttpServletResponse rep)
    {
        HttpSession session=req.getSession();
        System.out.println(session.getId());
        return "test";
    }

spring MVC无需视图解析器的实现：

return "redirect:/index.jsp";//重定向
return "forward:/index.jsp";//转发