import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.servlet.ModelAndView;

@Controller

public class Params {

    public Params() {

        System.out.println("costructor....");

    }

    /*

     * 方式1:通过注入httpServletRequest进行参数设置,并跟随返回的视图传递到页面

     */

    @RequestMapping("/ppp1")

    public String param(HttpServletRequest req) {

        req.setAttribute("msg", "you");

        return "/WEB-INF/hello.jsp";

    }

    /*

     * 方式2:通过原始的modelAndView设置模型数据和视图名称,,并返回

     */

    @RequestMapping("/ppp2")

    public ModelAndView param2() {

        ModelAndView mav = new ModelAndView();

        User user = new User();

        user.setName("俩后");

        mav.addObject("user", user);

        mav.setViewName("/WEB-INF/hello.jsp");

        mav.addObject("msg", "ck");

        return mav;

    }

    /*

     * 方式3:通过向方法注入形参Model类的对象,该对象由spring自动功能创建添加,model对象添加模型数据

     * 而返回的字符串负责指向要跳转的视图名称

     */

    @RequestMapping("/ppp3")

    public String param3(Model model) {

        User user = new User();

        user.setName("俩后的");

        model.addAttribute("user", user);

        model.addAttribute("msg", "ck");

        return "/WEB-INF/hello.jsp";

    }

    /*

     * 方式4:直接将返回值作为模型对象返回

     * 此时,视图名就是该方法的访问地址,即/ppp4,

     */

    @RequestMapping("/ppp4")

    public User param4() {

        User user = new User();

        user.setName("俩后的");

        return user;

    }

}