jBPM is agnostic to any UI framework you want to use, i.e, it does not matter if you use Spring MVC, Struts, JSF, Swing, GWT etc. You can use jBPM API from any framework you like.
Here are some examples to see how the jBPM API is used. You can have the API calls from your Spring MVC framework.
http://docs.jboss.org/jbpm/v5.1/userguide/ch08.html#d0e2894
http://sourceforge.net/projects/jbpm/files/jBPM%205/jbpm-5.1.0.Final/jbpm-5.1.0.Final-examples.zip/download