feat: implements completed MediaItemsCOntroller

Author: Meiko-S22

lesson_26/api/java/api_app/src/main/java/com/codedifferently/lesson26/web/CreateMediaItemRequest.java

@@ -14,8 +14,4 @@
 public class CreateMediaItemRequest {
   @NotNull(message = "item is required") @Valid
   private MediaItemRequest item;
-
-  MediaItemRequest getItem() {
-    throw new UnsupportedOperationException("Not supported yet.");
-  }
 }

lesson_26/api/java/api_app/src/main/java/com/codedifferently/lesson26/web/MediaItemsController.java

@@ -42,12 +42,11 @@ public ResponseEntity<GetMediaItemsResponse> getItems() {
   }
 
   @PostMapping("/items")
-  public ResponseEntity<CreateMediaItemResponse> postItem(
-      @Valid @RequestBody CreateMediaItemRequest request) {
+  public ResponseEntity<CreateMediaItemResponse> postItem(@Valid @RequestBody CreateMediaItemRequest request) {
     MediaItemRequest itemRequest = request.getItem();
-    MediaItem item = MediaItemRequest.asMediaItem(itemRequest);
-    library.addMediaItem(item, librarian);
-    MediaItemResponse itemResponse = MediaItemResponse.from(item);
+    MediaItem newItem = MediaItemRequest.asMediaItem(itemRequest);
+    library.addMediaItem(newItem, librarian);
+    MediaItemResponse itemResponse = MediaItemResponse.from(newItem);
     CreateMediaItemResponse response = CreateMediaItemResponse.builder().item(itemResponse).build();
     return ResponseEntity.ok(response);
   }