【发布时间】：2017-12-07 09:30:09
【问题描述】：
如何通过 GSON Android 正确序列化此类 JSON？
[
{
"id": "bitcoin",
"name": "Bitcoin",
"symbol": "BTC",
"rank": "1",
"price_usd": "15022.7",
"price_btc": "1.0",
"24h_volume_usd": "13711300000.0",
"market_cap_usd": "251264422255",
"available_supply": "16725650.0",
"total_supply": "16725650.0",
"max_supply": "21000000.0",
"percent_change_1h": "0.94",
"percent_change_24h": "17.4",
"percent_change_7d": "47.71",
"last_updated": "1512638053"
},
{
"id": "ethereum",
"name": "Ethereum",
"symbol": "ETH",
"rank": "2",
"price_usd": "427.071",
"price_btc": "0.0291936",
"24h_volume_usd": "2007350000.0",
"market_cap_usd": "41078436955.0",
"available_supply": "96186435.0",
"total_supply": "96186435.0",
"max_supply": null,
"percent_change_1h": "-1.59",
"percent_change_24h": "-5.64",
"percent_change_7d": "-3.22",
"last_updated": "1512638054"
}
]
数据类：
class AllCurrenсyData {
@SerializedName("")
@Expose
var currency: List<Currency>? = null
}
class Currency {
@SerializedName("price_usd")
@Expose
val priceUsd: String? = null
@SerializedName("symbol")
@Expose
val symbol: String? = null
@SerializedName("last_updated")
@Expose
val lastUpdated: String? = null
@SerializedName("total_supply")
@Expose
val totalSupply: String? = null
@SerializedName("24h_volume_usd")
@Expose
val jsonMember24hVolumeUsd: String? = null
@SerializedName("price_btc")
@Expose
val priceBtc: String? = null
@SerializedName("available_supply")
@Expose
val availableSupply: String? = null
@SerializedName("market_cap_usd")
@Expose
val marketCapUsd: String? = null
@SerializedName("percent_change_1h")
@Expose
val percentChange1h: String? = null
@SerializedName("percent_change_24h")
@Expose
val percentChange24h: String? = null
@SerializedName("name")
@Expose
val name: String? = null
@SerializedName("max_supply")
@Expose
val maxSupply: String? = null
@SerializedName("rank")
@Expose
val rank: String? = null
@SerializedName("id")
@Expose
val id: String? = null
@SerializedName("percent_change_7d")
@Expose
val percentChange7d: String? = null
}
为了实现这一点，我创建了这样的类。但是我正在听这样一堆错误：
FATAL EXCEPTION: main
Process: it.incode.cryptocoins, PID: 2620
io.reactivex.exceptions.OnErrorNotImplementedException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was BEGIN_ARRAY at line 1 column 2 path $
at io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:704)
at io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:701)
at io.reactivex.internal.observers.LambdaObserver.onError(LambdaObserver.java:74)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.checkTerminated(ObservableObserveOn.java:276)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.drainNormal(ObservableObserveOn.java:172)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.run(ObservableObserveOn.java:252)
at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:109)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6164)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)
Caused by: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was BEGIN_ARRAY at line 1 column 2 path $
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:224)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:37)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:25)
at retrofit2.ServiceMethod.toResponse(ServiceMethod.java:118)
at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:212)
at retrofit2.OkHttpCall.execute(OkHttpCall.java:174)
at com.jakewharton.retrofit2.adapter.rxjava2.CallObservable.subscribeActual(CallObservable.java:41)
at io.reactivex.Observable.subscribe(Observable.java:10842)
at com.jakewharton.retrofit2.adapter.rxjava2.BodyObservable.subscribeActual(BodyObservable.java:34)
at io.reactivex.Observable.subscribe(Observable.java:10842)
at io.reactivex.internal.operators.observable.ObservableMap.subscribeActual(ObservableMap.java:33)
at io.reactivex.Observable.subscribe(Observable.java:10842)
at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96)
at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:452)
at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:61)
at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:52)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:272)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
Caused by: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was BEGIN_ARRAY at line 1 column 2 path $
at com.google.gson.stream.JsonReader.beginObject(JsonReader.java:385)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:213)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:37)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:25)
at retrofit2.ServiceMethod.toResponse(ServiceMethod.java:118)
at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:212)
at retrofit2.OkHttpCall.execute(OkHttpCall.java:174)
at com.jakewharton.retrofit2.adapter.rxjava2.CallObservable.subscribeActual(CallObservable.java:41)
at io.reactivex.Observable.subscribe(Observable.java:10842)
at com.jakewharton.retrofit2.adapter.rxjava2.BodyObservable.subscribeActual(BodyObservable.java:34)
at io.reactivex.Observable.subscribe(Observable.java:10842)
at io.reactivex.internal.operators.observable.ObservableMap.subscribeActual(ObservableMap.java:33)
at io.reactivex.Observable.subscribe(Observable.java:10842)
at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96)
at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:452)
at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:61)
at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:52)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:272)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
很可能我没有正确处理没有序列化名称的数据数组。我希望有人能告诉我我的错误在哪里。
【问题讨论】：
-
无论您在哪里使用
AllCurrenсyData，只需使用List<Currency>。你最终的 json 是一个列表，你不需要像AllCurrenсyData这样的对象，只是一个列表。这也是你的例外所说的。 -
谢谢！它正在工作。
标签： android json kotlin gson retrofit2