Sometimes it would be nice to access a Java library directly from Kettle. You might find it useful for validation, lookup or custom cryptography support, just to give a few examples. Sometimes even basic access to data is not as straightforward as getting a file dump or a using a database connection. Some data sources might be encapsulated in an application, and the only way to get your hands on it, is using a custom Java client. This article explains how you can directly utilize your Java classes in Kettle a.k.a. PDI.
NOTE: If you’re using Kettle 4.0 or later, you also have the option to use the new User Defined Java Class step.