PHP

Camel supports PHP among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration.

To use a PHP expression use the following Java code

... php("somePHPExpression") ... 

For example you could use the php function to create an Predicate in a Message Filter or as an Expression for a Recipient List

ScriptContext

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.

Attributes

You can add your own attributes with the attribute(name, value) DSL method, such as:

In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned.

from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users");

Any scripting language

Camel can run any JSR-223 scripting languages using the script DSL method such as:

from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users");

This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):

    <from uri="direct:in"/>
    <setHeader headerName="firstName">
        <expression language="jaskel">user.firstName</expression>
    </setHeader>
    <to uri="seda:users"/>

You can also use predicates e.g. in a Filter:

    <filter>
        <language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
        <to uri="direct:next" />
    </filter>

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

Some languages without specific DSL support but known to work with these generic methods include:

Language Implementation language="..." value
BeanShell BeanShell 2.0b5 beanshell or bsh

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:

    public void testArgumentsExample() throws Exception {
        if (!ScriptTestHelper.canRunTestOnThisPlatform()) {
            return;
        }

        getMockEndpoint("mock:result").expectedMessageCount(0);
        getMockEndpoint("mock:unmatched").expectedMessageCount(1);

        // additional arguments to ScriptEngine
        Map<String, Object> arguments = new HashMap<String, Object>();
        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 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".

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

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

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

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>