[CONF] Apache Camel > Scripting Languages Context

[Claus Ibsen (Confluence)]

Scripting Languages Context Page edited by Claus Ibsen Changes (3) ... | 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. | h3. 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. {code:java} from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); {code} h3. Any scripting language Camel can run any JSR-223 scripting languages using the {{script}} DSL method such as: {code:java} from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); {code} This is a bit different using the Spring DSL where you use the *_expression_* element that doesn't support setting attributes (yet): {code:xml} <from uri="direct:in"/> <setHeader headerName="firstName"> <language language="jaskel">user.firstName</language> </setHeader> <to uri="seda:users"/> {code} You can also use predicates e.g. in a Filter: {code:xml} <filter> <language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language> <to uri="direct:next" /> </filter> {code} 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|http://svn.apache.org/repos/asf/servicemix/m2-repo/org/beanshell/bsh/2.0b5/bsh-2.0b5.jar]|{{beanshell}} or {{bsh}}| h3. Additional arguments to ScriptingEngine *Available as of Camel 2.8* ... 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|Download]). {code:xml} <dependency> <groupId>org.apache.camel</groupId> ... Full Content 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. 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". .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'))") 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: .setHeader("myHeader").groovy("resource:classpath:mygroovy.groovy") 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> Stop watching space | Change email notification preferences View Online | View Changes | Add Comment