如何在 Spring Cloud Stream Kafka 應用程序中根據條件向多個主題之一發送消息

Question

目前我有一個 spring clound 函數，它使用一個主題並發布到另一個主題。 現在我有多個主題，需要根據來自 spring 雲 function 的某些檢查將消息發布到多個主題之一。我該如何實現？ 這是當前的實現。

@Bean("producerBean")
    public Function<Message<SourceMessage>, Message<SinkMessage>> producerBean(SinkService<SourceMessage> sinkService) {
        return sinkService::processMessage;
    }

@Service("SinkService")
public class SinkService<T> {

    public Message<SinkMessage> processMessage(Message<SourceMessage> message) {
        log.info("Message consumed at {} \n{}", message.getHeaders().getTimestamp(), message.getPayload());
        try {
            if (message.getPayload().isManaged()) {
                /*
                Need to add one more check here.
                if (type==2)
                    send to topic1
                else if(type==4)
                    send to topic2
                else
                    Just log the type, do not send to any topic.
                 */
                Message<SinkMessage> output = new GenericMessage<>(new SinkMessage());
                output.getPayload().setPayload(message.getPayload());
                return output;
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return null;
    }
}

應用程序.properties

spring.cloud.stream.kafka.binder.brokers=${bootstrap.servers}
spring.cloud.stream.kafka.binder.configuration.enable.idempotence=false
spring.cloud.stream.binders.test_binder.type=kafka

spring.cloud.stream.bindings.producerBean.binder=test_binder
spring.cloud.stream.bindings.producerBean-in-0.destination=${input-destination}
spring.cloud.stream.bindings.producerBean-in-0.group=${input-group}
spring.cloud.stream.bindings.producerBean-out-0.destination=topic1
spring.cloud.stream.bindings.producerBean-out-1.destination=topic2

pom.xml

<dependency>
   <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-stream-kafka</artifactId>
    <version>3.2.5</version>
</dependency>

Answer 1

您可以將 StreamBridge 與 kafka-topicname 一起使用，spring-cloud 將在運行時自動綁定它。 如果主題不存在，該方法也會自動創建主題，您可以將其關閉。

@Autowired private final StreamBridge streamBridge;

public void sendDynamically(Message message, String topicName) {
    streamBridge.send(route, topicName);
}

https://docs.spring.io/spring-cloud-stream/docs/current/reference/html/spring-cloud-stream.html#_streambridge_and_dynamic_destinations