We are using the Kettle Java API to execute Kettle transformations in a server application. I would like to be able to use the User Defined Java Class in this context and have it load classes from an external jar. Could anyone tell me how to do this? When I am running the UDJC within spoon I am able to do this using launcher.properties to set libraries / classpath where our jar is located. But I want to do this not running in spoon but in our Java application. Any help is much appreciated. Thanks.