| = ConsumerTemplate |
| |
| The `ConsumerTemplate` interface allows you to receive message exchanges from |
| endpoints in a variety of different ways to make it easy to work with |
| Camel xref:endpoint.adoc[Endpoint] instances from Java code. |
| |
| It can be configured with a default endpoint if you just want to receive |
| lots of messages to the same endpoint; or you can specify an |
| xref:endpoint.adoc[Endpoint] or uri as the first parameter. |
| |
| The `receiveBody()` method allows you to receive any object to an endpoint |
| easily as shown: |
| |
| [source,java] |
| ---- |
| ConsumerTemplate template = exchange.getContext().createConsumerTemplate(); |
| |
| // recieve from default endpoint |
| Object body = template.receiveBody(); |
| |
| // receive from a specific queue |
| body = template.receiveBody("activemq:MyQueue"); |
| ---- |
| |
| == Receive modes |
| |
| The consumer template operates in three modes: |
| |
| - **receive** - Consumes from the endpoint, waiting until there is a message (can potentially wait for a long time!). |
| - **receiveNoWait** - Consumes from endpoint, not waiting for a message if none exists. |
| - **receiveTimeout** - Consumes from the endpoint, waiting until there is a response, or the timeout occurs. |
| |
| In the previous examples then it was the first mode we used (`receiveBody`). |
| For example if there are no messages on the `activemq:MyQueue` then Camel would wait until a message is sent to this queue. |
| |
| Often you dont want to wait _forever_ so its often a good idea to use a timeout value, such as 5 seconds: |
| |
| [source,java] |
| ---- |
| ConsumerTemplate template = exchange.getContext().createConsumerTemplate(); |
| |
| // receive from a specific queue |
| body = template.receiveBody("activemq:MyQueue", 5000); |
| ---- |
| |
| Here we wait at most 5 seconds for a message to be consumed, if there was no message, then `null` is returned as response. |
| |
| == See Also |
| |
| See xref:producertemplate.adoc[ProducerTemplate] |
