HTTP endpoints are webservices' main entrypoint. Attackers will take advantage of any vulnerability by sending crafted inputs for headers (including cookies), body and URI. No input should be trusted and extreme care should be taken with all returned value (header, body and status code).
In the case of the Spring framework, methods of a ``++@Controller++`` object annotated with ``++@RequestMapping++`` (or all its variants such as ``++@GetMapping++``, ``++@PostMapping++``, ``++@PutMapping++``, ``++@PatchMapping++`` and ``++@DeleteMapping++``) are declaring HTTP endpoints.