Exercise.getAllByCustomerId fix, HTTP test

src/main/kotlin/com/aitrainer/api/controller/ExerciesController.kt

@@ -6,10 +6,19 @@ import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.*
 import javax.validation.Valid
 
+@RestController
+@RequestMapping("/api")
 class ExerciesController(private val exercisesRepository: ExercisesRepository) {
 
+    @GetMapping("/exercises/{id}")
+    fun getExerciseById(@PathVariable(value = "id") exerciseId: Long): ResponseEntity<Exercises> {
+        return exercisesRepository.findById(exerciseId).map { exercise ->
+            ResponseEntity.ok(exercise)
+        }.orElse(ResponseEntity.notFound().build())
+    }
+
     @GetMapping("/exercises/customer/{id}")
-    fun getAllExersicesByCustomerId(customerId: Long): List<Exercises> =
+    fun getAllExersicesByCustomerId(@PathVariable( value = "id" ) customerId: Long? ): List<Exercises> =
             exercisesRepository.getAllByCustomerId(customerId)
 
     @PostMapping("/exercises")