[[Header-HeaderExpressionLanguage]]
Header Expression Language
~~~~~~~~~~~~~~~~~~~~~~~~~~

The Header Expression Language allows you to extract values of named
headers.

[[Header-Options]]
Header Options
^^^^^^^^^^^^^^

// language options: START
The Header language supports 1 options which are listed below.



{% raw %}
[width="100%",cols="2,1m,1m,6",options="header"]
|=======================================================================
| Name | Default | Java Type | Description
| trim | true | Boolean | Whether to trim the value to remove leading and trailing whitespaces and line breaks
|=======================================================================
{% endraw %}
// language options: END

[[Header-Exampleusage]]
Example usage
^^^^^^^^^^^^^

The recipientList element of the Spring DSL can utilize a header
expression like:

In this case, the list of recipients are contained in the header
'myHeader'.

And the same example in Java DSL:

And with a slightly different syntax where you use the builder to the
fullest (i.e. avoid using parameters but using stacked operations,
notice that header is not a parameter but a stacked method call)

[source,java]
------------------------------------------------------
  from("direct:a").recipientList().header("myHeader");
------------------------------------------------------

[[Header-Dependencies]]
Dependencies
^^^^^^^^^^^^

The Header language is part of *camel-core*.
