SpringBoot jackson序列化应用

package com.example.demo.controller;

import com.example.demo.entity.User;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import java.util.*;

@Controller
public class UserController {

    @Autowired
    private ObjectMapper mapper;

    /**
     * jackson树遍历
     * @return
     */
    @RequestMapping(value="/readTree",method= RequestMethod.POST)
    @ResponseBody
    public String readTree(){
        try{
            String str = "{\"name\":\"wes\",\"age\":10}";
            JsonNode node = mapper.readTree(str);
            String name = node.get("name").asText();
            Integer age = node.get("age").asInt();
            return "name:"+name+",age:"+age;
        }catch (Exception e) {
           System.out.println(e.getMessage());
        }
        return null;
    }

    /**
     * jackson json绑定对象
     * @return
     */
    @RequestMapping(value="/readValue",method= RequestMethod.POST)
    @ResponseBody
    public String readValue(){
        try{
            String json = "{\"name\":\"wes\",\"id\":10}";
            User user = mapper.readValue(json,User.class);
            return "name:"+user.getName()+",id:"+user.getId();
        }catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return null;
    }

    /**
     * jackson 将POJO序列化成json
     * @return
     */
    @RequestMapping(value="/writeValueAsString",method= RequestMethod.POST)
    @ResponseBody
    public String writeValueAsString(){
        try{
           User user = new User();
            user.setId("1");
            user.setName("张三");
            String json = mapper.writeValueAsString(user);
            return json;
        }catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return null;
    }
}