To use a Groovy expression use the following Java code
You should add the camel-groovy dependeny when using Groovy language with Camel. The generic camel-script is not optimized for best Groovy experience, and hence you should add camel-groovy as dependency.
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...
...Camel will use your custom GroovyShell instance (containing your custom static imports), instead of the default one.
And the Spring DSL:
JSR-223 scripting language's
ScriptContext is pre-configured with the following attributes all set at
The Camel Context.
The Camel Context (cannot be used in groovy).
The current Exchange.
Camel 2.9: Function with a
See Scripting Languages for the list of languages with explicit DSL support.
Passing Additional Arguments to the
Available from Camel 2.8
You can provide additional arguments to the
ScriptingEngine using a header on the Camel message with the key
Using Properties Function
Available from Camel 2.9
If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. For example, to set a header name
myHeader with a value from a property placeholder, whose key is taken from a header named
From Camel 2.9: you can now use the properties function and the same example is simpler:
Loading Script From External Resource
Available from Camel 2.11
You can externalize the script and have Camel load it from a resource such as
http:. This is done using the following syntax:
resource:scheme:location e.g. to refer to a file on the classpath you can do:
How to Get the Result from Multiple Statements Script
Available from Camel 2.14
The script engine's eval method returns a
null when it runs a multi-statement script. However, Camel can look up the value of a script's result by using the key
result from the value set. When writing a multi-statement script set the value of the
result variable as the script return value.
textbar = "baz"; # some other statements ... # camel take the result value as the script evaluation result result = body * 2 + 1
To use scripting languages in your camel routes you need to add the a dependency on
camel-script which integrates the JSR-223 scripting engine.
If you use maven you could just add the following to your
pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions).