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Question

public static void main(String args[] ){
   //project id
   String projectId = ServiceOptions.getDefaultProjectId();
   //topic id
   String topicId = args[0];

    // Create a new topic
    ProjectTopicName topic = ProjectTopicName.of(projectId, topicId);
    try (TopicAdminClient topicAdminClient = TopicAdminClient.create()) {
          System.out.println("Topics");
          topicAdminClient.createTopic(topic);
          System.out.printf("Topic %s:%s created.\n", topic.getProject(),                           
                                topic.getTopic());
    } catch(ApiException e) {
       System.out.println(e.getStatusCode().getCode());
       System.out.println(e.isRetryable());
    }
}

[INFO] Running com.example.pubsub.QuickStartIT
[ERROR] Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 301.26 s <<< FAILURE! - in com.example.pubsub.QuickStartIT
[ERROR] testQuickstart(com.example.pubsub.QuickStartIT)  Time elapsed: 301.153 s  <<< ERROR!
org.junit.runners.model.TestTimedOutException: test timed out after 300 seconds  
        at com.example.pubsub.QuickStartIT.deleteTestSubscription(QuickStartIT.java:144)  
        at com.example.pubsub.QuickStartIT.setUp(QuickStartIT.java:80)

Answer 1

您所提到的示例被配置为直接在Google Cloud上运行。为了使示例在本地pub/sub仿真程序上工作，您必须在代码中指定它应该连接到仿真程序主机。

主机端口应添加到代码中：

String hostport = System.getenv("PUBSUB_EMULATOR_HOST");
ManagedChannel channel = ManagedChannelBuilder.forTarget(hostport).usePlaintext().build();
try {
  TransportChannelProvider channelProvider =
      FixedTransportChannelProvider.create(GrpcTransportChannel.create(channel));
  CredentialsProvider credentialsProvider = NoCredentialsProvider.create();

  // Set the channel and credentials provider when creating a `TopicAdminClient`.
  // Similarly for SubscriptionAdminClient
  TopicAdminClient topicClient =
      TopicAdminClient.create(
          TopicAdminSettings.newBuilder()
              .setTransportChannelProvider(channelProvider)
              .setCredentialsProvider(credentialsProvider)
              .build());

  ProjectTopicName topicName = ProjectTopicName.of("my-project-id", "my-topic-id");
  // Set the channel and credentials provider when creating a `Publisher`.
  // Similarly for Subscriber
  Publisher publisher =
      Publisher.newBuilder(topicName)
          .setChannelProvider(channelProvider)
          .setCredentialsProvider(credentialsProvider)
          .build();
} finally {
  channel.shutdown();
}

您可以在公共文档中找到关于如何正确设置环境以使用本地pub/sub模拟器的更多信息。