我正在研究Google Cloud Pub/Sub publishing example。
我使用示例中的代码，但使用自己的项目ID和主题名称除外。
当尝试运行该示例时，我得到以下堆栈跟踪：
Exception in thread "main" java.util.concurrent.ExecutionException: com.google.api.gax.rpc.UnavailableException: io.grpc.StatusRuntimeException: UNAVAILABLE
at com.google.common.util.concurrent.AbstractFuture.getDoneValue(AbstractFuture.java:552)
at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:533)
at com.google.common.util.concurrent.AbstractFuture$TrustedFuture.get(AbstractFuture.java:90)
at com.google.common.util.concurrent.ForwardingFuture.get(ForwardingFuture.java:62)
at app.purephotos.zipper.Application.main(Application.java:87)
Caused by: com.google.api.gax.rpc.UnavailableException: io.grpc.StatusRuntimeException: UNAVAILABLE
at com.google.api.gax.rpc.ApiExceptionFactory.createException(ApiExceptionFactory.java:69)
at com.google.api.gax.grpc.GrpcApiExceptionFactory.create(GrpcApiExceptionFactory.java:72)
at com.google.api.gax.grpc.GrpcApiExceptionFactory.create(GrpcApiExceptionFactory.java:60)
at com.google.api.gax.grpc.GrpcExceptionCallable$ExceptionTransformingFuture.onFailure(GrpcExceptionCallable.java:97)
at com.google.api.core.ApiFutures$1.onFailure(ApiFutures.java:68)
at com.google.common.util.concurrent.Futures$CallbackListener.run(Futures.java:1015)
at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:30)
at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1137)
at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:957)
at com.google.common.util.concurrent.AbstractFuture.setException(AbstractFuture.java:748)
at io.grpc.stub.ClientCalls$GrpcFuture.setException(ClientCalls.java:515)
at io.grpc.stub.ClientCalls$UnaryStreamToFuture.onClose(ClientCalls.java:490)
at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
at io.grpc.internal.CensusStatsModule$StatsClientInterceptor$1$1.onClose(CensusStatsModule.java:700)
at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
at io.grpc.internal.CensusTracingModule$TracingClientInterceptor$1$1.onClose(CensusTracingModule.java:399)
at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:507)
at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:66)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:627)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$700(ClientCallImpl.java:515)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:686)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:675)
at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: io.grpc.StatusRuntimeException: UNAVAILABLE
at io.grpc.Status.asRuntimeException(Status.java:533)
... 24 more
Caused by: java.net.NoRouteToHostException: No route to host (Host unreachable)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at java.net.Socket.<init>(Socket.java:434)
at java.net.Socket.<init>(Socket.java:244)
at javax.net.DefaultSocketFactory.createSocket(SocketFactory.java:277)
at io.grpc.okhttp.OkHttpClientTransport$4.run(OkHttpClientTransport.java:541)
at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
... 3 more
我正在使用服务帐户的凭据。我确信凭据是有效的，因为我尝试错误地设置了凭据的路径不正确，并且它立即告诉我找不到具有凭据的文件。