来自另一条消费者路线的输入的骆驼消费者路线

Question

I have a kafka consumer route from where I get some data.

from("Kafka:foo?brokers=localhost:9092")

Once I receive data from the consumer, use that data in the topic name for a paho mqtt consumer.

from("paho:#?brokerUrl=tcp://localhost:1883")

I'm not able to figure out how to set the dynamic header CamelMqttTopic, from first consumer, as both seems independent flows. I'm using camel with Spring framework. Excuse me if my basic camel understanding is flawed.

Answer 1

You can override the MQTT topic using the CamelPahoOverrideTopic message header with a value being the Kafka topic accessed through the kafka.TOPIC message header:

from("kafka:foo?brokers=localhost:9092")
    .setHeader(PahoConstants.CAMEL_PAHO_OVERRIDE_TOPIC, simple("${headers[kafka.TOPIC]"))
    .to("paho:#?brokerUrl=tcp://localhost:1883");