Amends the Generic solution to PATCH HTPP requests.

Author: brunodrugowick

src/main/java/dev/drugowick/algaworks/algafoodapi/api/controller/CityController.java

@@ -26,12 +26,10 @@ public class CityController {
 
     private CityRepository cityRepository;
     private CityCrudService cityCrudService;
-    private ObjectMerger<City> objectMerger;
 
-    public CityController(CityRepository cityRepository, CityCrudService cityCrudService, ObjectMerger<City> objectMerger) {
+    public CityController(CityRepository cityRepository, CityCrudService cityCrudService) {
         this.cityRepository = cityRepository;
         this.cityCrudService = cityCrudService;
-        this.objectMerger = objectMerger;
     }
 
     @GetMapping
@@ -98,7 +96,9 @@ public ResponseEntity<?> partialUpdate(@PathVariable Long id, @RequestBody Map<S
             return ResponseEntity.notFound().build();
         }
 
-        cityToUpdate = objectMerger.mergeRequestBodyToGenericObject(cityMap, cityToUpdate);
+        ObjectMerger
+                .of(City.class)
+                .mergeRequestBodyToGenericObject(cityMap, cityToUpdate);
 
         return update(id, cityToUpdate);
     }

src/main/java/dev/drugowick/algaworks/algafoodapi/api/controller/CuisineController.java

@@ -26,12 +26,10 @@ public class CuisineController {
 
 	private CuisineRepository cuisineRepository;
 	private CuisineCrudService cuisinesCrudService;
-	private ObjectMerger<Cuisine> objectMerger;
 
-	public CuisineController(CuisineRepository cuisineRepository, CuisineCrudService cuisinesCrudService, ObjectMerger<Cuisine> objectMerger) {
+	public CuisineController(CuisineRepository cuisineRepository, CuisineCrudService cuisinesCrudService) {
 		this.cuisineRepository = cuisineRepository;
 		this.cuisinesCrudService = cuisinesCrudService;
-		this.objectMerger = objectMerger;
 	}
 
 	@GetMapping
@@ -82,7 +80,9 @@ public ResponseEntity<?> partialUpdate(@PathVariable Long id, @RequestBody Map<S
 			return ResponseEntity.notFound().build();
 		}
 
-		cuisineToUpdate = objectMerger.mergeRequestBodyToGenericObject(cuisineMap, cuisineToUpdate);
+		ObjectMerger
+				.of(Cuisine.class)
+				.mergeRequestBodyToGenericObject(cuisineMap, cuisineToUpdate);
 
 		return update(id, cuisineToUpdate);
 	}

src/main/java/dev/drugowick/algaworks/algafoodapi/api/controller/ProvinceController.java

@@ -26,12 +26,10 @@ public class ProvinceController {
 
 	private ProvinceRepository provinceRepository;
 	private ProvinceCrudService provinceCrudService;
-	private ObjectMerger<Province> objectMerger;
 
-	public ProvinceController(ProvinceRepository provinceRepository, ProvinceCrudService provinceCrudService, ObjectMerger<Province> objectMerger) {
+	public ProvinceController(ProvinceRepository provinceRepository, ProvinceCrudService provinceCrudService) {
 		this.provinceRepository = provinceRepository;
 		this.provinceCrudService = provinceCrudService;
-		this.objectMerger = objectMerger;
 	}
 
 	@GetMapping
@@ -88,7 +86,9 @@ public ResponseEntity<?> partialUpdate(@PathVariable Long id, @RequestBody Map<S
 			return ResponseEntity.notFound().build();
 		}
 
-		provinceToUpdate = objectMerger.mergeRequestBodyToGenericObject(provinceMap, provinceToUpdate);
+		ObjectMerger
+				.of(Province.class)
+				.mergeRequestBodyToGenericObject(provinceMap, provinceToUpdate);
 
 		return update(id, provinceToUpdate);
 	}

src/main/java/dev/drugowick/algaworks/algafoodapi/api/controller/RestaurantController.java

@@ -18,11 +18,9 @@
 public class RestaurantController {
 
 	private RestaurantCrudService restaurantCrudService;
-	private ObjectMerger<Restaurant> objectMerger;
 
-	public RestaurantController(RestaurantCrudService restaurantCrudService, ObjectMerger<Restaurant> objectMerger) {
+	public RestaurantController(RestaurantCrudService restaurantCrudService) {
 		this.restaurantCrudService = restaurantCrudService;
-		this.objectMerger = objectMerger;
 	}
 
 	@GetMapping
@@ -85,7 +83,9 @@ public ResponseEntity<?> partialUpdate(@PathVariable Long id, @RequestBody Map<S
 			return ResponseEntity.notFound().build();
 		}
 
-		restaurantToUpdate = objectMerger.mergeRequestBodyToGenericObject(restaurantMap, restaurantToUpdate);
+		ObjectMerger
+				.of(Restaurant.class)
+				.mergeRequestBodyToGenericObject(restaurantMap, restaurantToUpdate);
 
 		return update(id, restaurantToUpdate);
 	}

src/main/java/dev/drugowick/algaworks/algafoodapi/api/controller/utils/ObjectMerger.java

@@ -18,12 +18,29 @@ public class ObjectMerger<T> {
     private ObjectMapper objectMapper;
     private Class<T> type;
 
-    public ObjectMerger(Class<T> type) {
+    private ObjectMerger(Class<T> type) {
         this.objectMapper = new ObjectMapper();
         this.type = type;
     }
 
-    public T mergeRequestBodyToGenericObject(Map<String, Object> objectMap, T objectToUpdate) {
+    /**
+     * Returns a new instance of ObjectMerger<T> of the given type as parameter.
+     *
+     * @param type a class to be merged with a Map of <String, Object>.
+     * @return
+     */
+    public static ObjectMerger of(Class type) {
+        return new ObjectMerger(type);
+    }
+
+    /**
+     * Updates an objectToUpdate according to data from a Map<String, Object>.
+     *
+     * @param objectMap      a Map of <String, Object> with data to update destination object. The string values
+     *                       must match fields on the destination object.
+     * @param objectToUpdate the object to update.
+     */
+    public void mergeRequestBodyToGenericObject(Map<String, Object> objectMap, T objectToUpdate) {
         T newObject = objectMapper.convertValue(objectMap, type);
 
         objectMap.forEach((fieldProp, valueProp) -> {
@@ -34,7 +51,5 @@ public T mergeRequestBodyToGenericObject(Map<String, Object> objectMap, T object
 
             ReflectionUtils.setField(field, objectToUpdate, newValue);
         });
-
-        return objectToUpdate;
     }
 }