springMVC-笔记007-几种return

package com.mvc.contorller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

/**
* SpringMVC的几种返回值： 1.ModelAndView 2.String 3.void
*
* @author Administrator
*/
@Controller
public class ReturnController {

// 第一种：ModelAndView
@RequestMapping("/rt01/{rt}")
public ModelAndView return01(@PathVariable("rt") String rt01) {
// 另一种方式：
// ModelAndView mav = new ModelAndView("testreturn");
ModelAndView mav = new ModelAndView();
// 数据
mav.addObject("rt", rt01);
// 视图路径
mav.setViewName("testreturn");
return mav;
}

// 第二种：String
@RequestMapping("/rt02/{rt}")
public String return02(@PathVariable("rt") String rt02, Model model) {
// 数据
model.addAttribute("rt", rt02);
// 返回视图路径
return "testreturn";
}

// 第三种：void
@RequestMapping("/rt03")
public void return03(HttpServletRequest request, HttpServletResponse response) throws Exception {
// ...
// Json
}

}