Android Jetpack Tile抛出Java.util.concurrent.cancellation exception

Question

我正在开发一个Android Wear Tile，偶尔会以此堆栈跟踪崩溃。

2022-06-22 15:19:24.753 24101-24101/myapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: myapp, PID: 24101
    java.util.concurrent.CancellationException
        at kotlinx.coroutines.guava.JobListenableFuture.getInternal(ListenableFuture.kt:438)
        at kotlinx.coroutines.guava.JobListenableFuture.get(ListenableFuture.kt:428)
        at androidx.wear.tiles.TileService$TileProviderWrapper.lambda$onTileRequest$0(TileService.java:234)
        at androidx.wear.tiles.TileService$TileProviderWrapper$$ExternalSyntheticLambda7.run(Unknown Source:4)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:246)
        at android.app.ActivityThread.main(ActivityThread.java:7690)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:593)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:995)
     Caused by: kotlinx.coroutines.JobCancellationException: Job was cancelled; job=JobImpl{Cancelled}@d298571

我认为这是当我的瓷砖令人耳目一新的时候发生。我的瓷砖是使用Raturofit从REST API获取数据。该代码看起来像这样：

class WeatherTileService : TileService() {
    private val serviceScope = CoroutineScope(Dispatchers.IO)

    override fun onTileRequest(requestParams: TileRequest) = serviceScope.future {
        Log.d("Tile", "Refreshing weather data")
        val api = AmbientWeatherClient.getInstance()
        val devices = api.listUsersDevices(APP_KEY, API_KEY)
...
        Tile.Builder()
            .setResourcesVersion(RESOURCES_VERSION)
            .setFreshnessIntervalMillis(5 * 60 * 1000)
            .setTimeline(

interface AmbientWeatherAPI {

    @GET("devices")
    suspend fun listUsersDevices(
        @Query("applicationKey") applicationKey: String,
        @Query("apiKey") apiKey: String
    ): List<Device>

}

我不知道为什么会发生这种情况。有什么建议从哪里开始挖掘？

Answer 1

我感到惊讶的是，取消杀死了您的应用程序。但是您有一个10秒钟的窗口来完成该请求。我怀疑这是取消。

/**
 * Called when the system is requesting a new timeline from this Tile Service. The returned
 * future must complete after at most 10 seconds from the moment this method is called (exact
 * timeout length subject to change).
 *
 * <p>Note that this is called from your app's main thread, which is usually also the UI thread.
 *
 * @param requestParams Parameters about the request. See {@link TileRequest} for more info.
 */
@MainThread
@NonNull
protected abstract ListenableFuture<Tile> onTileRequest(@NonNull TileRequest requestParams);

我的建议将永远不会在NittilereQuest上进行任何可变长度工作，例如调用远程API。从缓存（例如房间数据库）提供服务通常更有意义。

同样，当瓷砖请求进来时可能无法使用网络。由于这个和许多其他原因，通常最好拥有一些背景过程更新数据，例如Workmanager。然后，这可以将更新发送给您的瓷砖，也可以将任何复杂性或应用本身发送。