json 对象属性的输出顺序测试，fastJson 有序，jackson,gson无序（需代码中人工按约定来编码）接口数据签名规则

package com.example.core.mydemo.json5;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.gson.Gson;

import java.util.ArrayList;
import java.util.List;

/**
 * 测试券对象
 */
public class MyCouponIdObject {
    private String sex;
    private Integer orderType;
    private String couponCode;
    private String name;

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getName() {
        return name;
    }

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

    private static final ObjectMapper MAPPER = new ObjectMapper();

    public String getCouponCode() {
        return couponCode;
    }

    public void setCouponCode(String couponCode) {
        this.couponCode = couponCode;
    }

    public Integer getOrderType() {
        return orderType;
    }

    public void setOrderType(Integer orderType) {
        this.orderType = orderType;
    }

    public static void main(String[] args) {
        MyCouponIdObject c1 = new MyCouponIdObject();
        c1.setOrderType(1);
        c1.setCouponCode("111");
        c1.setName("Eric");
        c1.setSex("男");

        System.out.println("fastJson=" + JSON.toJSONString(c1));


        try {
            System.out.println("jackson=" + MAPPER.writeValueAsString(c1));
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }

        System.out.println("gson=" + new Gson().toJson(c1));
        
        /**
         * fastJson={"couponCode":"111","orderType":1}
         * jackson={"orderType":1,"couponCode":"111"}
         * gson={"orderType":1,"couponCode":"111"}
         *
         * 新增两个字段后 output
         * fastJson={"couponCode":"111","name":"Eric","orderType":1,"sex":"男"}
         * jackson={"sex":"男","orderType":1,"couponCode":"111","name":"Eric"}
         * gson={"sex":"男","orderType":1,"couponCode":"111","name":"Eric"}
         * 发现：fastJson会根据字段的首字母来排序。
         * 而jackson,gson是根据对象的类中定义的属性的先后顺序输出。
         */
    }
}