feat：库存仓储服务

route/src/main/java/pers/amos/mall/route/dal/dataobject/InventoryDO.java

@@ -54,6 +54,12 @@ public class InventoryDO implements Serializable {
      */
     private Integer remainingStock;
 
+    /**
+     * 乐观锁版本号
+     */
+    @Version
+    private Integer version;
+
     /**
      * 创建时间
      */

route/src/main/java/pers/amos/mall/route/dal/repository/InventoryRepository.java

@@ -1,22 +1,18 @@
 package pers.amos.mall.route.dal.repository;
 
+import com.baomidou.mybatisplus.extension.service.IService;
 import pers.amos.mall.route.dal.dataobject.InventoryDO;
 
 /**
  * 库存仓储接口
  */
-public interface InventoryRepository {
+public interface InventoryRepository extends IService<InventoryDO> {
     
     /**
      * 根据库存编码查询
      */
     InventoryDO findByInventoryCode(String inventoryCode);
-    
-    /**
-     * 保存库存
-     */
-    void save(InventoryDO inventoryDO);
-    
+
     /**
      * 更新库存（乐观锁）
      */

route/src/main/java/pers/amos/mall/route/dal/repository/impl/InventoryRepositoryImpl.java

@@ -0,0 +1,50 @@
+package pers.amos.mall.route.dal.repository.impl;
+
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.core.toolkit.Wrappers;
+import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
+import org.springframework.stereotype.Repository;
+import pers.amos.mall.common.log.LogUtil;
+import pers.amos.mall.route.dal.dataobject.InventoryDO;
+import pers.amos.mall.route.dal.mapper.InventoryMapper;
+import pers.amos.mall.route.dal.repository.InventoryRepository;
+
+/**
+ * 库存Repository实现
+ */
+@Repository
+public class InventoryRepositoryImpl extends ServiceImpl<InventoryMapper, InventoryDO> implements InventoryRepository {
+    
+    @Override
+    public InventoryDO findByInventoryCode(String inventoryCode) {
+        LambdaQueryWrapper<InventoryDO> queryWrapper = Wrappers.lambdaQuery(InventoryDO.class)
+                .eq(InventoryDO::getInventoryCode, inventoryCode);
+        
+        return this.getOne(queryWrapper);
+    }
+    
+    @Override
+    public boolean updateWithVersion(InventoryDO inventoryDO) {
+        // MyBatis-Plus 的 @Version 注解会自动处理乐观锁
+        // 更新时会自动：
+        // 1. WHERE 条件加上 version = 当前版本
+        // 2. SET version = version + 1
+        // 3. 如果 affected rows = 0，说明版本冲突或库存不足
+        
+        // 额外检查：确保剩余库存不为负数
+        if (inventoryDO.getRemainingStock() < 0) {
+            LogUtil.warn("库存更新失败（剩余库存为负）, inventoryCode={}, remainingStock={}", 
+                    inventoryDO.getInventoryCode(), inventoryDO.getRemainingStock());
+            return false;
+        }
+        
+        boolean success = this.updateById(inventoryDO);
+        
+        if (!success) {
+            LogUtil.warn("库存更新失败（乐观锁冲突）, inventoryCode={}, version={}", 
+                    inventoryDO.getInventoryCode(), inventoryDO.getVersion());
+        }
+        
+        return success;
+    }
+}