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ScriptContext Options

 

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

camelContext

Attribute

Type

Value

contextcamelContext

org.apache.camel.CamelContext

The Camel Context ( It cannot be used in groovy)

.

context

org.apache.camel.CamelContext

The Camel Context (cannot be used in groovy).

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.

request

org.apache.camel.Message

The IN message.

response

org.apache.camel.Message

Deprecated: The OUT message. The OUT message is null by default. Use the IN message instead.

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

Passing Additional

...

Arguments to the ScriptingEngine

Available as of from 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:

Wiki Markup
{snippet:id=e1|lang=java|url=camel/trunk/components/camel-script/src/test/java/org/apache/camel/builder/script/JavaScriptExpressionTest.java}

Using properties function

Example:

Code Block
languagejava
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 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 name myHeader with a value from a property placeholder, which whose key is provided in taken from a header named "foo".

Code Block
languagegroovy
.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:

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


Loading

...

Script From External Resource

Available as of 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", eg e.g. to refer to a file on the classpath you can do:

Code Block
languagejava
.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).

Code Block
xml
languagexml
<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-script</artifactId>
  <version>x.x.x</version>
</dependency>