package com.myy.ssm.controller;
import com.myy.ssm.model.Book;
import com.myy.ssm.service.BookService;
import com.myy.ssm.utils.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 * @author 熊贝贝
 * @site www.myy.com
 * @company
 * @create  2019-11-23 14:28
 * springmvc中五种返回值处理情况
 * 转发三种
 *  转发到安全目录web-inf下
 *  转发到根目录
 *  转发到requestMapping
 * 重定向两种
 *  根目录
 *  requestMapping
@Controller
public class HelloController {
    @Autowired
    private BookService bookService;
    @RequestMapping("/say1")
    public String say1(){
        return "hello";
    @RequestMapping("/say2")
    public ModelAndView say2(){
        ModelAndView mv = new ModelAndView();
        mv.setViewName("/hello2");
        mv.addObject("msg","换种方式继续");
        return mv;
    //转发到安全目录web-inf下
    @RequestMapping("/req1")
    public String req1() {
        System.out.println("转发到安全目录web-inf下...");
        return "a";
    //转发到根目录
    @RequestMapping("/req2")
    public String req2() {
        System.out.println("转发到根目录...");
        return "forward:/b.jsp";
    //转发到requestMapping
    @RequestMapping("/req3")
    public String req3() {
        System.out.println("转发到requestMapping...");
        return "forward:/req2";
    //根目录
    @RequestMapping("/red1")
    public String red1() {
        System.out.println("red1...");
        return "redirect:/b.jsp";
    //requestMapping
    @RequestMapping("/red2")
    public String red2() {
        System.out.println("red2...");
        return "redirect:/req2";
    @ResponseBody
    @RequestMapping("/json1")
    public Map json1(HttpServletRequest req){
//        ObjectMapper om = new ObjectMapper();
//        String s = om.writeValueAsString("这里既可以放map，也可以放list，也可放字符串");
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        List<Map> list = bookService.listPager(new Book(), pageBean);
        Map map = new HashMap();
        map.put("total",101);
        map.put("data",list);
        return map;
    @ResponseBody
    @RequestMapping("/json2")
    public List<Map> json2(HttpServletRequest req){
//        ObjectMapper om = new ObjectMapper();
//        String s = om.writeValueAsString("这里既可以放map，也可以放list，也可放字符串");
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        List<Map> list = bookService.listPager(new Book(), pageBean);
        return list;
    @ResponseBody
    @RequestMapping("/json3")
    public String json3(HttpServletRequest req){
        return "springmvc string to json";
 
@ResponseBody 将结果进行json转换
 
分别运行显示：
 json2:

 json2:

 json格式：
 
	"bname": "斗破第13章",
	"price": 13.0,
	"bid": 13
}, {
	"bname": "圣墟第16章",
	"price": 16.0,
	"bid": 16
}, {
	"bname": "圣墟第18章",
	"price": 18.0,
	"bid": 18
}, {
	"bname": "圣墟第19章",
	"price": 19.0,
	"bid": 19
}, {
	"bname": "圣墟第20章",
	"price": 20.0,
	"bid": 20
}, {
	"bname": "圣墟第21章",
	"price": 21.0,
	"bid": 21
}, {
	"bname": "圣墟第22章",
	"price": 22.0,
	"bid": 22
}, {
	"bname": "仙逆第23章",
	"price": 23.0,
	"bid": 23
}, {
	"bname": "圣墟第24章",
	"price": 24.0,
	"bid": 24
}, {
	"bname": "斗破",
	"price": 123.0,
	"bid": 25
json1:

 json格式：
 
	"total": 101,
	"data": [{
		"bname": "斗破第13章",
		"price": 13.0,
		"bid": 13
	}, {
		"bname": "圣墟第16章",
		"price": 16.0,
		"bid": 16
	}, {
		"bname": "圣墟第18章",
		"price": 18.0,
		"bid": 18
	}, {
		"bname": "圣墟第19章",
		"price": 19.0,
		"bid": 19
	}, {
		"bname": "圣墟第20章",
		"price": 20.0,
		"bid": 20
	}, {
		"bname": "圣墟第21章",
		"price": 21.0,
		"bid": 21
	}, {
		"bname": "圣墟第22章",
		"price": 22.0,
		"bid": 22
	}, {
		"bname": "仙逆第23章",
		"price": 23.0,
		"bid": 23
	}, {
		"bname": "圣墟第24章",
		"price": 24.0,
		"bid": 24
	}, {
		"bname": "斗破",
		"price": 123.0,
		"bid": 25
 
json在线解析：https://www.sojson.com/