add item classes

Java-Knight/src/main/java/org/project/constants/gameConstant/ItemClass.java

@@ -0,0 +1,12 @@
+package org.project.constants.gameConstant;
+
+public enum ItemClass {
+    KEY,
+    SELLABLE,
+    UNNECESSARY,
+    ACCESSORY,
+    SHIELD,
+    WEAPON,
+    COSTUME,
+}
+

Java-Knight/src/main/java/org/project/constants/gameConstant/ItemClassExt.java

@@ -0,0 +1,25 @@
+package org.project.constants.gameConstant;
+
+import org.project.item.Accessory.Accessory;
+import org.project.item.Accessory.Costume;
+import org.project.item.Accessory.Shield;
+import org.project.item.Accessory.Weapon;
+import org.project.item.KeyItem;
+import org.project.item.SellableItem;
+
+public final class ItemClassExt {
+    private ItemClassExt() {}
+
+    public static boolean Matches(ItemClass itemClass, Object subject) {
+        return switch (itemClass) {
+            case KEY -> subject instanceof KeyItem;
+            case SELLABLE -> subject instanceof SellableItem;
+            case UNNECESSARY -> subject.getClass() == SellableItem.class;
+            case ACCESSORY -> subject instanceof Accessory;
+            case WEAPON -> subject instanceof Weapon;
+            case COSTUME -> subject instanceof Costume;
+            case SHIELD -> subject instanceof Shield;
+            case null, default -> false;
+        };
+    }
+}