Android使用Kotlin利用Gson解析多层嵌套Json数据

1、依赖

build.gradle(app)中加入

dependencies {
implementation 'com.google.code.gson:gson:2.8.9'
}

2、解析

1. 假设这是要解析Json数据

var responseStr =
"{
	"code": 200,
	"message": "操作成功",
	"data": {
		"pageNum": 1,
		"pageSize": 5,
		"totalPage": 2,
		"total": 8,
		"list": [{
			"id": 1,
			"username": "test",
			"password": "123",
			"icon": "https://macro-oss.oss-cn-shenzhen.aliyuncs.com/mall/icon/github_icon_02.png",
			"email": "[email protected]",
			"nickName": "测试账号",
			"note": null,
			"createTime": "2018-09-29T05:55:30.000+00:00",
			"loginTime": "2018-09-29T05:55:39.000+00:00",
			"status": 1
		}, {
			"id": 3,
			"username": "admin",
			"password": "123",
			"icon": "https://macro-oss.oss-cn-shenzhen.aliyuncs.com/mall/icon/github_icon_01.png",
			"email": "[email protected]",
			"nickName": "系统管理员",
			"note": "系统管理员",
			"createTime": "2018-10-08T05:32:47.000+00:00",
			"loginTime": "2019-04-20T04:45:16.000+00:00",
			"status": 1
		}, {
			"id": 4,
			"username": "macro",
			"password": "123",
			"icon": "https://macro-oss.oss-cn-shenzhen.aliyuncs.com/mall/icon/github_icon_01.png",
			"email": "[email protected]",
			"nickName": "macro",
			"note": "macro专用",
			"createTime": "2019-10-06T07:53:51.000+00:00",
			"loginTime": "2020-02-03T06:55:55.000+00:00",
			"status": 1
		}, {
			"id": 6,
			"username": "productAdmin",
			"password": "123",
			"icon": "https://macro-oss.oss-cn-shenzhen.aliyuncs.com/mall/icon/github_icon_03.png",
			"email": "[email protected]",
			"nickName": "商品管理员",
			"note": "只有商品权限",
			"createTime": "2020-02-07T08:15:08.000+00:00",
			"loginTime": null,
			"status": 1
		}, {
			"id": 7,
			"username": "orderAdmin",
			"password": "123",
			"icon": "https://macro-oss.oss-cn-shenzhen.aliyuncs.com/mall/icon/github_icon_04.png",
			"email": "[email protected]",
			"nickName": "订单管理员",
			"note": "只有订单管理权限",
			"createTime": "2020-02-07T08:15:50.000+00:00",
			"loginTime": null,
			"status": 1
		}]
	}
}     

2. 分析Json的结构

• Json主要构成部分
  
  对应的类

data class Result(
    val code: Int,
    val message: String,
    val data: Data
) : Serializable

• data部分的组成
  
  对应的类：

data class Data(
    val pageNum: Int,
    val pageSize: Int,
    val totalPage: Int,
    val total: Int,
    val list: List<list> = ArrayList(),
) : Serializable

Json中list使用[ ]，所以这里的list写成： val list: List = ArrayList()

• list部分的组成
  
  对应的类：

data class list(
    val id: Int,
    val username: String,
    val password: String,
    val icon: String,
    val email: String,
    val nickName: String,
    val createTime: String,
    val loginTime: String,
    val status: Int
) : Serializable

重点提醒：类里面的属性名必须跟Json字段里面的Key是一模一样的，否则会导致解析不成功
如果不一致：

这个部分我刚开始处理也错了，找了好久才发现，一定要注意

3. 开始解析

		val gson = Gson()
        val resultType = object :  TypeToken<Result>() {}.type
        val fromJson = gson.fromJson<Result>(responseStr, resultType)

4. 提取数据
   通过fromJson提取
   如：