jpashop : item entity

jpashop/src/main/java/com/example/jpashop/domain/item/Item.java

@@ -1,6 +1,7 @@
 package com.example.jpashop.domain.item;
 
 import com.example.jpashop.domain.Category;
+import com.example.jpashop.exception.NotEnoughStockException;
 import lombok.Getter;
 import lombok.Setter;
 
@@ -24,4 +25,24 @@ public abstract class Item {
 
     @ManyToMany(mappedBy = "items")
     private List<Category> categories = new ArrayList<>();
+
+    // 비지니스 로직
+
+    /**
+     *  stock 증가
+     */
+    public void addStock(int quantity) {
+        this.stockQuantity += quantity;
+    }
+
+    /**
+     *  stock 감소
+     */
+    public void removeStock(int quantity) {
+        int restStock = this.stockQuantity - quantity;
+        if (restStock < 0) {
+            throw new NotEnoughStockException("need more stock0");
+        }
+        this.stockQuantity = restStock;
+    }
 }

jpashop/src/main/java/com/example/jpashop/exception/NotEnoughStockException.java

@@ -0,0 +1,20 @@
+package com.example.jpashop.exception;
+
+public class NotEnoughStockException extends RuntimeException {
+
+    public NotEnoughStockException() {
+        super();
+    }
+
+    public NotEnoughStockException(String message) {
+        super(message);
+    }
+
+    public NotEnoughStockException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public NotEnoughStockException(Throwable cause) {
+        super(cause);
+    }
+}