Question

我有google cloud pubsub订阅者应用程序（问题与pubsub无关，我相信与jms监听器有相同的行为）。 它不需要像tomcat或其他这样的网络容器（有很多问题，问题是缺少容器依赖，这里我不需要webcontainer）。它应该启动并处理消息。问题：它在启动后停止。

应用程序非常简单，这里是build.gradle文件：

buildscript {
    ext {
        springBootVersion = '1.5.8.RELEASE'
    }
    repositories {
        mavenLocal()
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'org.springframework.boot'

sourceCompatibility = 1.8
targetCompatibility = 1.8

repositories {
    mavenLocal()
    mavenCentral()
}

dependencies {
    compile 'org.springframework.boot:spring-boot-starter'
}

这是应用程序启动器：

@SpringBootApplication
public class CommunicationApplication {

    public static void main(String[] args) throws IOException {
        SpringApplication.run(CommunicationApplication.class, args);

        //waiting data from system input to prevent stop after start
        //System.in.read();
    }

}

这是pubsub manager bean（它创建了pubsub监听器）

@Component
public class PubsubManager {

    private final Logger logger = LoggerFactory.getLogger(getClass());

    @Autowired
    private MessageReceiver messageReceiver;

    private Subscriber subscriber;

    @PostConstruct
    protected void start() throws Exception {
        createTopic();
        createSubscriber();
    }

    private void createTopic() throws Exception {
        TopicName topic = TopicName.of(ServiceOptions.getDefaultProjectId(), "COMMUNICATION_TOPIC_NAME");
        try (TopicAdminClient topicAdminClient = TopicAdminClient.create()) {
            topicAdminClient.createTopic(topic);
            logger.info("Topic {}:{} created", topic.getProject(), topic.getTopic());
        } catch (ApiException e) {
            if (e.getStatusCode().getCode() == StatusCode.Code.ALREADY_EXISTS) {
                logger.info("Topic {}:{} already exist", topic.getProject(), topic.getTopic());
            } else {
                logger.error("Error create topic: {}", e.getStatusCode().getCode());
            }
            logger.info("isRetryable: {}", e.isRetryable());
        }
    }

    private void createSubscriber() throws Exception {
        SubscriptionName subscriptionName = SubscriptionName.of(ServiceOptions.getDefaultProjectId(),
                MessagingConstants.COMMUNICATION_SUBSCRIPTION_NAME);
        // create a subscriber bound to the asynchronous message receiver
        try (SubscriptionAdminClient subscriptionAdminClient = SubscriptionAdminClient.create()) {
            TopicName topicName = TopicName.of(ServiceOptions.getDefaultProjectId(),
                    "COMMUNICATION_TOPIC_NAME");
            Subscription subscription = subscriptionAdminClient.createSubscription(
                            subscriptionName, topicName, PushConfig.getDefaultInstance(), 0);
        } catch (Exception e) {
            logger.info("subscription already created:", e);
        }
        subscriber = Subscriber.newBuilder(subscriptionName, messageReceiver).build();
        subscriber.startAsync().awaitRunning();
        logger.info("subscriber start receiving messages");
    }

    @PreDestroy
    protected void close() throws Exception {
        logger.info("subscriber stop receiving messages");
        subscriber.stopAsync();
    }
}

如果我取消注释System.in.read(); - 它适用于本地环境，但在云端它不起作用。你能建议正确的解决方法吗？感谢。

Answer 1

如果您只想创建PubSub Listener，以下内容对我有用：

git clone https://github.com/spring-guides/gs-messaging-gcp-pubsub
cd gs-messaging-gcp-pubsub/complete
将build.gradle文件更改为下面的build.gradle文件。
cd gs-messaging-gcp-pubsub/complete/src/main/resources进入后，您可以删除静态文件夹。
转到gs-messaging-gcp-pubsub / complete / src / main / java / hello;在那里你应该有两个文件：PubSubApplication.java和WebAppController.java。删除WebAppController.java并将PubSubApplication.java更改为以下文件：

的build.gradle：

buildscript { 
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.5.9.RELEASE")
    }    
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

jar {
    baseName = 'gs-spring-cloud-gcp'
    version =  '0.1.0'
}

repositories {
    mavenCentral()
    maven {
        url "http://repo.spring.io/snapshot"
    }
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies {
    compile("org.springframework.cloud:spring-cloud-gcp-starter-pubsub:1.0.0.BUILD-SNAPSHOT")
    compile("org.springframework.cloud:spring-integration-gcp:1.0.0.BUILD-SNAPSHOT")
}

pubSubApplication.java

package hello;

import java.io.IOException;

import com.google.cloud.pubsub.v1.AckReplyConsumer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.gcp.pubsub.core.PubSubOperations;
import org.springframework.cloud.gcp.pubsub.core.PubSubTemplate;
import org.springframework.cloud.gcp.pubsub.support.GcpHeaders;
import org.springframework.context.annotation.Bean;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.gcp.pubsub.AckMode;

import org.springframework.integration.gcp.pubsub.inbound.PubSubInboundChannelAdapter;
import org.springframework.integration.gcp.pubsub.outbound.PubSubMessageHandler;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;

@SpringBootApplication
public class PubSubApplication {

  private static final Log LOGGER = LogFactory.getLog(PubSubApplication.class);

  public static void main(String[] args) throws IOException {
    SpringApplication.run(PubSubApplication.class, args);
  }


  @Bean
  public MessageChannel pubsubInputChannel() {
    return new DirectChannel();
  }

  @Bean
  public PubSubInboundChannelAdapter messageChannelAdapter(
      @Qualifier("pubsubInputChannel") MessageChannel inputChannel,
      PubSubOperations pubSubTemplate) {
    PubSubInboundChannelAdapter adapter =
        new PubSubInboundChannelAdapter(pubSubTemplate, "testSubscription");
    adapter.setOutputChannel(inputChannel);
    adapter.setAckMode(AckMode.MANUAL);

    return adapter;


      }

  @Bean
  @ServiceActivator(inputChannel = "pubsubInputChannel")
  public MessageHandler messageReceiver() {
    return message -> {
      LOGGER.info("Message arrived! Payload: " + message.getPayload());
      AckReplyConsumer consumer =
          (AckReplyConsumer) message.getHeaders().get(GcpHeaders.ACKNOWLEDGEMENT);
      consumer.ack();
    };

  }

}

更改“testSubscription”to the Subscription you are using

现在在文件夹gs-messaging-gcp-pubsub / complete中，如果运行./gradlew bootRun，应用程序hello.PubSubApplication应该在本地运行。您发布到订阅主题的任何消息都应显示在运行应用程序的位置。

如果您在凭据/认证方面遇到问题，请更改以下参数：

GS-消息传递的GCP-发布订阅/完整/ SRC /主/资源/ application.properties

启动后，Spring启动应用程序（不是Web）停止

1 个答案: