android - 关闭 SpeechClient 时出现 java.util.concurrent.RejectedExecutionException

Question

我正在使用 Google Speech Client 将语音转换为文本，它工作正常，但当我尝试将其关闭时抛出异常。

这是我用来初始化的代码。

private val mSpeechClient by lazy {

    applicationContext.resources.openRawResource(R.raw.credentials).use {
        SpeechClient.create(SpeechSettings.newBuilder()
                .setCredentialsProvider { GoogleCredentials.fromStream(it) }
                .build())
    }
}

但是当我调用

mSpeechClient.shutDown()

它抛出这个异常。

 Process: com.google.cloud.examples.speechrecognition, PID: 10080
java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask@11065d8d rejected from java.util.concurrent.ScheduledThreadPoolExecutor@3cbffe24[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 2]
    at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2011)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:793)
    at java.util.concurrent.ScheduledThreadPoolExecutor.delayedExecute(ScheduledThreadPoolExecutor.java:298)
    at java.util.concurrent.ScheduledThreadPoolExecutor.schedule(ScheduledThreadPoolExecutor.java:503)
    at java.util.concurrent.ScheduledThreadPoolExecutor.execute(ScheduledThreadPoolExecutor.java:592)
    at io.grpc.internal.SerializingExecutor.schedule(SerializingExecutor.java:93)
    at io.grpc.internal.SerializingExecutor.execute(SerializingExecutor.java:86)
    at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.closed(ClientCallImpl.java:594)
    at io.grpc.internal.DelayedStream$DelayedStreamListener$4.run(DelayedStream.java:418)
    at io.grpc.internal.DelayedStream$DelayedStreamListener.delayOrExecute(DelayedStream.java:372)
    at io.grpc.internal.DelayedStream$DelayedStreamListener.closed(DelayedStream.java:415)
    at io.grpc.internal.AbstractClientStream$TransportState.closeListener(AbstractClientStream.java:392)
    at io.grpc.internal.AbstractClientStream$TransportState.access$300(AbstractClientStream.java:200)
    at io.grpc.internal.AbstractClientStream$TransportState$1.run(AbstractClientStream.java:376)
    at io.grpc.internal.AbstractClientStream$TransportState.deframerClosed(AbstractClientStream.java:245)
    at io.grpc.internal.Http2ClientStreamTransportState.deframerClosed(Http2ClientStreamTransportState.java:31)
    at io.grpc.okhttp.OkHttpClientStream$TransportState.deframerClosed(OkHttpClientStream.java:275)
    at io.grpc.internal.MessageDeframer.close(MessageDeframer.java:233)
    at io.grpc.internal.MessageDeframer.closeWhenComplete(MessageDeframer.java:195)
    at io.grpc.internal.AbstractStream$TransportState.closeDeframer(AbstractStream.java:180)
    at io.grpc.internal.AbstractClientStream$TransportState.transportReportStatus(AbstractClientStream.java:379)
    at io.grpc.okhttp.OkHttpClientTransport.startGoAway(OkHttpClientTransport.java:739)
    at io.grpc.okhttp.OkHttpClientTransport.access$1900(OkHttpClientTransport.java:92)
    at io.grpc.okhttp.OkHttpClientTransport$ClientFrameHandler.run(OkHttpClientTransport.java:936)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:818)

Answer 1

RejectedExecutionException 被抛出，因为新任务显然是在 ThreadExecutor 关闭后提交的。发生这种情况是由于 ThreadExecutor 中设置的默认处理程序策略 - ThreadPoolExecutor.AbortPolicy。

• In the default ThreadPoolExecutor.AbortPolicy, the handler throws a runtime RejectedExecutionException upon rejection.

由于您正在手动关闭您的客户端 mSpeechClient.shutDown() 及其内部的 ThreadExecutor，为了解决您可能需要更改处理程序策略的问题到以下之一:

• In ThreadPoolExecutor.CallerRunsPolicy, the thread that invokes execute itself runs the task. This provides a simple feedback control mechanism that will slow down the rate that new tasks are submitted.
• In ThreadPoolExecutor.DiscardPolicy, a task that cannot be executed is simply dropped.
• In ThreadPoolExecutor.DiscardOldestPolicy, if the executor is not shut down, the task at the head of the work queue is dropped, and then execution is retried (which can fail again, causing this to be repeated.)

以上，是对引用自ThreadPoolExecutor的handler policies描述的解释Java文档。

为此，您需要使用您选择的策略设置创建 ThreadExecutor 的自定义实例，然后将其传递给您的客户端。这应该可以解决问题。