Ref

Since Camel 2.8

The Ref Expression Language is really just a way to lookup a custom Expression or Predicate from the Registry.

This is particular useable in XML DSLs.

Ref Language options

The Ref language supports 2 options, which are listed below.

Name Default Java Type Description

resultType (common)

String

Sets the class of the result type (type from output).

trim (advanced)

true

Boolean

Whether to trim the source code to remove leading and trailing whitespaces and line breaks. For example when using DSLs where the source will span across multiple lines and there may be additional line breaks at both the beginning and end.

Example usage

The Splitter EIP can utilize a custom expression using ref like:

  • Java

  • XML

  • YAML

from("seda:a").split().ref("myExpression").to("seda:b");
<bean id="myExpression" class="com.mycompany.MyCustomExpression"/>

<route>
  <from uri="seda:a"/>
  <split>
    <ref>myExpression</ref>
    <to uri="mock:b"/>
  </split>
</route>
- route:
    from:
      uri: seda:a
      steps:
        - split:
            expression:
              ref:
                expression: myExpression
            steps:
              - to:
                  uri: mock:b

In this case, the message coming from the seda:a endpoint will be split using a custom Expression which has the id myExpression in the Registry.

Dependencies

The Ref language is part of camel-core.

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