How to do an integration test for a Spring Boot application?

TLDR: Should you test a compiled JAR or is it enough to write a @Test method to run the main class?

I have a Spring Boot service that integrates with several other services.

Currently, in order to test the integration between the services I'm running the compiled JAR in sort of a staging environment while simulating the other services.

Is there a benefit of running the compiled JAR over running a unit test that runs the main application and mocks (e.g. using Mockito) the other services?

Or maybe, do I need both of these capabilities?