It depends on the kind of changes that you want to inject.
That said, I believe there is a deeper issue here. Restarting Jetty is the right thing to do from a test-quality standpoint. It ensures that each test starts from a clean page thereby minimizing the risk of inter-test dependencies. On the other hand, this is costly (time-wise) and make your suite runs slower.
If I were you, I would address this as follows: I will refactor the code that I want to test (presumably: servlets) such that they do not depend on the Jetty infrastructure, and can run stand-alone. For instance, If I have a servlet class SomeServlet
with its doGet()
method, I will refactor it such that it implement MyServelt
whose goGet()
takes a MyRequest
, MyResponse
parameters.
Once you do that, you can unit-test MyServlet
without a Jetty server. This will allow you not only to test faster, but also ease your debugging sessions and make your components more decoupled. Of course, you will need to add some plumbing code: a class that adapts the servelt interface to a MyServelt object (via delegation).