Camel supports BeanShell among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration.
To use a BeanShell expression use the following Java code:
Or the something like this in your Spring XML:
You must use BeanShell 2.0b5 or greater. Note that as of 2.0b5 BeanShell cannot compile scripts, which causes Camel releases before 2.6 to fail when configured with BeanShell expressions.
You could follow the examples above to create an Predicate in a Message Filter or as an Expression for a Recipient List
The JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
| Attribute || Type || Value |
| context || org.apache.camel.CamelContext || The Camel Context |
| exchange || org.apache.camel.Exchange || The current Exchange |
| request || org.apache.camel.Message || The IN message |
| response || org.apache.camel.Message || The OUT message |
| properties || org.apache.camel.builder.script.PropertiesFunction || Camel 2.9: Function with a resolve method to make it easier to use Camels Properties component from scripts. See further below for example. |
See Scripting Languages for the list of languages with explicit DSL support.
Additional arguments to ScriptingEngine
Available as of 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:
Using properties function
Available as of 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, which key is provided in a header named "foo".
From Camel 2.9 onwards you can now use the properties function and the same example is simpler:
Loading script from external resource
Available as of 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:
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).