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@Consume

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@MessageDriven is deprecated in Camel 1.x. You should use @Consume instead. Its removed in Camel 2.0.

To consume a message you use either the @MessageDriven annotation or from 1.5.0 the @Consume annotation to mark a particular method of a bean as being a consumer method. The uri of the annotation defines the Camel Endpoint to consume from.

e.g. lets invoke the onCheese() method with the String body of the inbound JMS message from ActiveMQ on the cheese queue; this will use the Type Converter to convert the JMS ObjectMessage or BytesMessage to a String - or just use a TextMessage from JMS

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Warning
title When using more than one CamelContext
When you use more than 1 CamelContext you might end up with each of them creating a POJO Consuming. In Camel 2.0 there is a new option ; therefore use the option context on @Consume that allows you to specify which CamelContext id/name you want it to apply for.

Using context option to apply only a certain CamelContext

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See the warning above.

You can use the context option to specify which CamelContext the consumer should only apply for. For example:

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Code Block
from(uri).to("bean:myBean?method=methodName");

Using a property to define the endpoint

Available as of Camel 2.11

The following annotations @Consume, @Produce, @EndpointInject, now offers a property attribute you can use to define the endpoint as a property on the bean. Then Camel will use the getter method to access the property.

For example

public class MyService {
  private String serviceEndpoint;
  
  public void setServiceEndpoint(String uri) {
     this.serviceEndpoint = uri;
  }

  public String getServiceEndpoint() {
     return serviceEndpoint
  }

  @Consume(property = "serviceEndpoint")
  public void onService(String input) {
     ...
  }
}

The bean MyService has a property named serviceEndpoint which has getter/setter for the property. Now we want to use the bean for POJO Consuming, and hence why we use @Consume in the onService method. Notice how we use the property = "serviceEndpoint to configure the property that has the endpoint url.

If you define the bean in Spring XML or Blueprint, then you can configure the property as follows:

<bean id="myService" class="com.foo.MyService">
  <property name="serviceEndpoint" value="activemq:queue:foo"/>
</bean>

This allows you to configure the bean using any standard IoC style.

Camel offers a naming convention which allows you to not have to explicit name the property.
Camel uses this algorithm to find the getter method. The method must be a getXXX method.

1. Use the property name if explicit given
2. If no property name was configured, then use the method name
3. Try to get the property with name*Endpoint* (eg with Endpoint as postfix)
4. Try to get the property with the name as is (eg no postfix or postfix)
5. If the property name starts with on then omit that, and try step 3 and 4 again.

So in the example above, we could have defined the @Consume annotation as

  @Consume(property = "service")
  public void onService(String input) {

Now the property is named 'service' which then would match step 3 from the algorithm, and have Camel invoke the getServiceEndpoint method.

We could also have omitted the property attribute, to make it implicit

  @Consume
  public void onService(String input) {

Now Camel matches step 5, and loses the prefix on in the name, and looks for 'service' as the property. And because there is a getServiceEndpoint method, Camel will use that.

Which approach to use?

Using the @MessageDriven/ @Consume annotations are simpler when you are creating a simple route with a single well defined input URI.

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