ScriptContext Options

The JSR-223 scripting language's ScriptContext is pre-configured with the following attributes all set at ENGINE_SCOPE.

See Scripting Languages for the list of languages with explicit DSL support.

Passing Additional Arguments to the ScriptingEngine

Available from Camel 2.8

You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments.

Example:

public void testArgumentsExample() throws Exception {
    getMockEndpoint("mock:result").expectedMessageCount(0);
    getMockEndpoint("mock:unmatched").expectedMessageCount(1);

    // additional arguments to ScriptEngine
    Map<String, Object> arguments = new HashMap<>();
    arguments.put("foo", "bar");
    arguments.put("baz", 7);

    // those additional arguments is provided as a header on the Camel Message
    template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments);

    assertMockEndpointsSatisfied();


 

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 foo.

.setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')")

From Camel 2.9: you can now use the properties function and the same example is simpler:

.setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))")

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 classpath:, file:, or http:. This is done using the following syntax: resource:scheme:location e.g. to refer to a file on the classpath you can do:

.setHeader("myHeader").groovy("resource:classpath:mygroovy.groovy")

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

Dependencies

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).

<dependency>
 <groupId>org.apache.camel</groupId>
 <artifactId>camel-script</artifactId>
 <version>x.x.x</version>
</dependency>