There is never just one answer on what libraries/frameworks to choose, and anyone who tells you that there is just one way you are "supposed to do it" probably isn't worth listening to :)

With that said, I am a big fan of Spring and I don't consider it "intrusive" as some other commenters do. But if you aren't interested in using it as a DI container then you may find it easier to just get closer to the other libraries used (i.e. Jersey etc) and avoid any helper code.