@GetMapping(value="")
public ResponseEntity<JsonResponse> getLocations(@RequestHeader(value="id") String id, @LocationType @RequestParam(value="locationType" ) String P_STS_AREA_TYP) {

    ...
    return new ResponseEntity<>(response,HttpStatus.OK);
}

@Target({ElementType.METHOD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = LocationTypeValidator.class)
public @interface LocationType {
String message() default "";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};

@Test
public void should_return_input_invalid_exception_for_invalid_location_type_for_get_location_endpoint() throws Exception {
    mockMvc.perform(get("/something/something/something")
            .param("locationType", "something")
            .header("id", "12345678"))
            .andExpect(status().isBadRequest());

}

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = { something.class, something.class})