[[groovy-language]]
= Groovy Language
:docTitle: Groovy
:artifactId: camel-groovy
:description: Evaluate a Groovy script.
:since: 1.3
:supportLevel: Stable

*Since Camel {since}*

Camel supports http://groovy.codehaus.org/[Groovy] among other
Scripting Languages to allow an
Expression or Predicate to be
used in the DSL or xref:manual::xml-configuration.adoc[Xml
Configuration].

To use a Groovy expression use the following Java code

[source,java]
---------------------------------------
... groovy("someGroovyExpression") ...
---------------------------------------

For example you could use the *groovy* function to create an
Predicate in a xref:{eip-vc}:eips:filter-eip.adoc[Message Filter] or as an Expression for a
Recipient List

== Groovy Options



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



[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
|===
// language options: END




== Customizing Groovy Shell

Sometimes you may need to use custom `GroovyShell` instance in your
Groovy expressions. To provide custom `GroovyShell`, add implementation
of the `org.apache.camel.language.groovy.GroovyShellFactory` SPI
interface to your Camel registry. For example after adding the following
bean to your Spring context...

[source,java]
----------------------------------------------------------------------
public class CustomGroovyShellFactory implements GroovyShellFactory {

  public GroovyShell createGroovyShell(Exchange exchange) {
    ImportCustomizer importCustomizer = new ImportCustomizer();
    importCustomizer.addStaticStars("com.example.Utils");
    CompilerConfiguration configuration = new CompilerConfiguration();
    configuration.addCompilationCustomizers(importCustomizer);
    return new GroovyShell(configuration);
  }

}
----------------------------------------------------------------------

...Camel will use your custom GroovyShell instance (containing your
custom static imports), instead of the default one.

=== Customizing Groovy class file name

You may rarely in need of customizing generated Groovy class file name for debugging purposes.
This is also possible by implementing `getFileName` method.

[source,java]
----------------------------------------------------------------------
public class CustomGroovyShellFactory implements GroovyShellFactory {

  public GroovyShell createGroovyShell(Exchange exchange) {
    return new GroovyShell();
  }

  public String getFileName(Exchange exchange) {
    return "Foo.groovy";
  }

}
----------------------------------------------------------------------

== Example

[source,java]
------------------------------------------------------------------------------------------------
// lets route if a line item is over $100
from("queue:foo").filter(groovy("request.lineItems.any { i -> i.value > 100 }")).to("queue:bar")
------------------------------------------------------------------------------------------------

And the Spring DSL:

[source,xml]
-----------------------------------------------------------------------------
        <route>
            <from uri="queue:foo"/>
            <filter>
                <groovy>request.lineItems.any { i -> i.value > 100 }</groovy>
                <to uri="queue:bar"/>
            </filter>
        </route>
-----------------------------------------------------------------------------

== Additional arguments to ScriptingEngine

*Since Camel 2.8*

You can provide additional arguments to the `ScriptingEngine` using a
header on the Camel message with the key `CamelScriptArguments`. +
 See this example:

== Loading script from external resource

*Since Camel 2.11*

You can externalize the script and have Camel load it from a resource
such as `"classpath:"`, `"file:"`, or `"http:"`. +
 This is done using the following syntax: `"resource:scheme:location"`,
eg to refer to a file on the classpath you can do:

[source,java]
-------------------------------------------------------------------
.setHeader("myHeader").groovy("resource:classpath:mygroovy.groovy")
-------------------------------------------------------------------

== How to get the result from multiple statements script

*Since Camel 2.14*

As the scripteengine evaluate method just return a Null if it runs a
multiple statements script. Camel now look up the value of script result
by using the key of "result" from the value set. If you have multiple
statements script, you need to make sure you set the value of result
variable as the script return value.

[source,text]
-------------------------------------------------------------
bar = "baz";
# some other statements ...
# camel take the result value as the script evaluation result
result = body * 2 + 1
-------------------------------------------------------------

== Dependencies

To use scripting languages in your camel routes you need to add a
dependency on *camel-groovy*.

If you use Maven you could just add the following to your `pom.xml`,
substituting the version number for the latest and greatest release (see
the download page for the latest versions).

[source,xml]
---------------------------------------
<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-groovy</artifactId>
  <version>x.x.x</version>
</dependency>
---------------------------------------

include::camel-spring-boot::page$groovy-starter.adoc[]
