如何一次从 JSON 对象中检索多个项目

Question

我试图在同一次传递中从下面的 JSON 中检索多个项目。我希望将每个“序列”实例的每个 originatorId 和消息检索为有序格式，以便我可以在回收器视图中显示它们，就像消息传递历史一样。

到目前为止，我已经尝试通过 Klaxon 使用模式匹配，但无法让它挑选出多个“消息”实例。我认为我的问题是找到一种方法来获取“更改”对象的每个实例，而不仅仅是第一个，例如=

"$.body.changes.event.message" -> does not work
"$.body.changes[0].event.message" -> returns only first message

{
    "kind": "notification",
    "body":
    {
        "changes": [
                {
                    "sequence": 0,
                    "originatorId": "d5305f84f7812530e746a713ebeabb457e59b380b779387de90ff0f7ff593e2a",
                    "originatorMetadata":
                    {
                        "id": "d5305f84f7812530e746a713ebeabb457e59b380b779387de90ff0f7ff593e2a",
                        "role": "CONSUMER"
                    },
                    "serverTimestamp": 1555330963355,
                    "event":
                    {
                        "type": "ContentEvent",
                        "message": "hello ",
                        "contentType": "text/plain"
                    },
                    "dialogId": "8e35bc87-c42f-4a28-837d-ac6d93cb119a"
                },
                {
                    "sequence": 2,
                    "originatorId": "73c29cd1-b3e3-56fc-a483-ba3409831d21",
                    "originatorMetadata":
                    {
                        "id": "73c29cd1-b3e3-56fc-a483-ba3409831d21",
                        "role": "ASSIGNED_AGENT"
                    },
                    "serverTimestamp": 1555330964870,
                    "event":
                    {
                        "type": "ContentEvent",
                        "message": "Hi Bob, how can I help you today? ????",
                        "contentType": "text/plain"
                    },
                    "dialogId": "8e35bc87-c42f-4a28-837d-ac6d93cb119a"
                },
                {
                    "sequence": 3,
                    "originatorId": "d5305f84f7812530e746a713ebeabb457e59b380b779387de90ff0f7ff593e2a",
                    "originatorMetadata":
                    {
                        "id": "d5305f84f7812530e746a713ebeabb457e59b380b779387de90ff0f7ff593e2a",
                        "role": "CONSUMER"
                    },
                    "serverTimestamp": 1555330975711,
                    "event":
                    {
                        "type": "ContentEvent",
                        "message": "hi",
                        "contentType": "text/plain"
                    },
                    "dialogId": "8e35bc87-c42f-4a28-837d-ac6d93cb119a"
                }

我的预期结果将是某种形式的映射，带有 originatorId 到消息，映射位置链接到序列。目前我只能将第一条消息“hello”和最后一个 originatorId 链接在一起。 进一步的工作将包括将 serverTimestamp 导出到相同的映射中。 我愿意为 Klaxon 使用不同的库。

这是我已经尝试使用的代码=

 val pathMatcher = object : PathMatcher {
                override fun pathMatches(path: String) = Pattern.matches(".*.message", path)

                override fun onMatch(path: String, value: Any) {

                    val origin = parseForOriginatorId(text)
                    val messageNew = Message(origin, timeReadNew, value.toString())

                    ChatActivity.adapter.addMessage(Message(origin, timeReadNew, value.toString()))
                    //messages[origin] = messageNew

                    Log.d("D", "Message: ${messageNew.originator}: ${messageNew.content}")

                    when (path) {
                        "$.body.changes.originatorId" -> Log.d("D", "======originator ID $value" )
                        "$.body.changes.event.message" -> Log.d("D", "=====Message $value")
                    }
                }
            }

            Klaxon().pathMatcher(pathMatcher)
                    .parseJsonObject(StringReader(text))
        }

Answer 1

遍历数组（一个例子）

 val myJsonArray = json.get("changes") as JSONArray

 for (i in 0..(myJsonArray.length() - 1)) {
     val item = myJsonArray[i] as JSONObject
 }