In the previous example, the logic was easily handled by either expressions or JavaScript within the business process. However, there may be cases when jBPM actions are better implemented in Java. For example, there might be an API readily available in Java that isn't available in JavaScript. Or suppose you want to manipulate workflows from outside a business process. May be you want to complete tasks, add items to a workflow, or start a workflow from an action, a web script, or a custom dialog. You could use the jBPM API directly to do these things, but a better approach is to go through Alfresco's Workflow Service. That way, you are insulated from any changes to the jBPM engine and, at least theoretically, from more drastic changes such as if Alfresco ever decides to swap out the workflow engine entirely.

The next example gives you a chance to try out both of these scenarios. In one, you're going to write a custom jBPM action. In the other, you are going to use the...