You probably won't find a lot of resources about this -
1.) It appears
there hasn't been a JPF release since 2007.
2.) The only reference I found about
how to get JPF to workin a webapp.
3.) Spring has
Spring/DM which uses OSGi.
However, given a cursory glance, it looks like nothing would prevent you from using Spring to bind together objects taken from a JPF PluginRegistry, or to build Plugins using Spring - there's just no built-in solution (or many examples).