Hi!
A suggestion, given the limited requirements:
I assume the web service you want to interrupt perform some lengthy process.
In the code implementing the lengthy process, you can add periodic
testing of some flag of some kind. I would use an instance of AtomicBoolean. If this flag is set, then the lengthy process is aborted.
Clicking the button in the JSP causes some kind of code to be invoked that set the flag discussed above.
Best wishes!