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，但是当我尝试将其关闭时抛出异常。

这是我用于初始化的代码。

private val mSpeechClient by lazy {

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

但是当我打电话时

mSpeechClient.shutDown()

它正在抛出这个异常。

 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 被抛出是因为新任务在ThreadExecutor 关闭后显然已提交给它。这是由于ThreadExecutor - ThreadPoolExecutor.AbortPolicy 中设置的默认处理程序策略所致。

• 在默认的ThreadPoolExecutor.AbortPolicy 中，处理程序抛出一个 运行时RejectedExecutionException 被拒绝。

由于您要手动关闭您的客户端 mSpeechClient.shutDown() 及其内部的 ThreadExecutor，为了解决问题，您可能需要将处理程序策略更改为以下之一：

• 在ThreadPoolExecutor.CallerRunsPolicy，调用的线程 execute 本身运行任务。这提供了一个简单的反馈 控制机制将减慢新任务的速度 已提交。
• 在ThreadPoolExecutor.DiscardPolicy，一个任务不能 被执行只是简单地删除。
• 在ThreadPoolExecutor.DiscardOldestPolicy中，如果执行器没有关闭 down，工作队列头部的任务被丢弃，然后 重试执行（可能再次失败，导致 重复。）

以上是对引用自ThreadPoolExecutorJavaDoc 的处理程序策略描述的解释。

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。