Struts doesn't dictate what back-end one can use, so you're pretty much free to do whatever you want. What you have sounds like a typical Data Access Object. There shouldn't be any problem using such a thing with Struts.
You should be separating your project in two: the model and the viewer. Typically you would have a service that encapsulates the access to the data and then you struts front-end would make use of that service to access the data.
I have found the using Spring Persistence in addition to Struts works well, since you hand off the opening and closing of databases session to Spring.