Json数据格式

json比较可读，通过键值对返回。实现通常有两种方式:一种是自己来构造，也就是用一个对象存储数据，在最后输出时将其json字符串化；第二种是使用 @RestController 注解实现json数据返回。

第一种 

导入依赖坐标：

        

            org.springframework.boot
            spring-boot-starter-json
        

实体类：

public class Pet {
    private Long id;
    private String name;
    private int age;
    private String color;
    private String description;

    public Pet(Long id, String name, int age, String color, String description) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.color = color;
        this.description = description;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

创建一个Controller进行测试：

@RestController
@RequestMapping("/test_json")
public class TestJson {
    @Autowired
    public Testjson testjson;
    @RequestMapping("/pet")
    public Pet getPet(){
        return new Pet(1L,"团团",2,"black","a cut panda");
    }
    @RequestMapping("/petList")
    public List getPetList(){
        List pets = new ArrayList<>();
        pets.add(new Pet(2L,"小狗",3,"write","a dog"));
        pets.add(new Pet(1L,"小猪",2,"pink","a pig"));
        return pets;
    }

}

完成。

第二种 

这里使用第三方代替实现，此方法比较粗糙不推荐使用，例如选择 alibaba 开源的 faskjson。依赖配置：

            com.alibaba
            fastjson
            2.0.25

 测试提供的实体类：

package org.example.pojo;

public class User {
    private String name;
    private String password;

    public User(String name, String password) {
        this.name = name;
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

测试类：

package org.example.service;

import com.alibaba.fastjson.JSON;
import org.example.pojo.User;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;
@Component
public class Testjson {
    public String objectToJson(){
        //单个Java 对象
        User user = new User("tfboys","2333");
        String userJsonStr = JSON.toJSONString(user);
        System.out.println("java类转json字符串为："+userJsonStr);
        //多个java 对象
        User user1 = new User("gameboy","2334");
        User user2 = new User("steatboy","456789");
        List users = new ArrayList<>();
        users.add(user1);
        users.add(user2);
        String ListUserJson = JSON.toJSONString(users);
        System.out.println("List