Chapter 28. Ref

Overview

The Ref expression language is really just a way to look up a custom Expression from the Registry. This is particular convenient to use in the XML DSL.
The Ref language is part of camel-core.

Static import

To use the Ref language in your Java application code, include the following import statement in your Java source files: 
import static org.apache.camel.language.simple.RefLanguage.ref;

XML example

For example, the splitter pattern can reference a custom expression using the Ref language, as follows: 
<beans ...>
  <bean id="myExpression" class="com.mycompany.MyCustomExpression"/>
  ...
  <camelContext>
    <route>
      <from uri="seda:a"/>
      <split>
        <ref>myExpression</ref>   
        <to uri="mock:b"/>
      </split>     
    </route>
  </camelContext>
</beans>

Java example

The preceding route can also be implemented in the Java DSL, as follows: 
from("seda:a")
  .split().ref("myExpression")
  .to("seda:b");