I am trying to integrate Bonita with Spring in order to implement a custom UI for my workflow processes.
I know Bonita provides a REST API out-of-the-box for this matter but I was thinking maybe there is already a java library for this API ready to use with Spring.
A first option would be to use the Bonita Java client library that can talk to Bonita Engine API using direct Java calls, HTTP or EJB. But this Java client does not enforce some security rules defined at an higher level. Moreover the current evolution focus on the Bonita Engine REST API.
So my recommendation would be to rather use the REST API and add a library (such as retrofit) to do the wrapping between your Java code and the REST API calls.
For my suggestion I recommend to keep a Bonita server running independently of your application. You just need to make sure that Bonita service is actually available before trying to call it.