feat: 种类属性管理，支持定义属性模板和商品属性值

src/main/java/com/example/building/service/CategoryAttributeService.java

@@ -0,0 +1,26 @@
+package com.example.building.service;
+
+import com.example.building.entity.CategoryAttribute;
+import com.baomidou.mybatisplus.extension.service.IService;
+import java.util.List;
+
+/**
+ * 种类属性服务接口
+ */
+public interface CategoryAttributeService extends IService<CategoryAttribute> {
+
+    /**
+     * 获取种类的所有属性
+     */
+    List<CategoryAttribute> getByCategoryId(String categoryId);
+
+    /**
+     * 保存属性
+     */
+    void saveAttributes(String categoryId, List<CategoryAttribute> attrs);
+
+    /**
+     * 删除种类的所有属性
+     */
+    void deleteByCategoryId(String categoryId);
+}

src/main/java/com/example/building/service/ProductAttributeService.java

@@ -0,0 +1,27 @@
+package com.example.building.service;
+
+import com.example.building.entity.ProductAttribute;
+import com.baomidou.mybatisplus.extension.service.IService;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * 商品属性服务接口
+ */
+public interface ProductAttributeService extends IService<ProductAttribute> {
+
+    /**
+     * 获取商品的属性值
+     */
+    List<ProductAttribute> getByProductId(String productId);
+
+    /**
+     * 保存商品属性值
+     */
+    void saveProductAttributes(String productId, List<Map<String, Object>> attrs);
+
+    /**
+     * 删除商品的所有属性
+     */
+    void deleteByProductId(String productId);
+}

src/main/java/com/example/building/service/impl/CategoryAttributeServiceImpl.java

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+package com.example.building.service.impl;
+
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
+import com.example.building.entity.CategoryAttribute;
+import com.example.building.mapper.CategoryAttributeMapper;
+import com.example.building.service.CategoryAttributeService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * 种类属性服务实现
+ */
+@Service
+public class CategoryAttributeServiceImpl implements CategoryAttributeService {
+
+    @Override
+    public List<CategoryAttribute> getByCategoryId(String categoryId) {
+        return this.list(new LambdaQueryWrapper<CategoryAttribute>()
+                .eq(CategoryAttribute::getCategoryId, categoryId)
+                .orderByAsc(CategoryAttribute::getSortOrder));
+    }
+
+    @Override
+    @Transactional
+    public void saveAttributes(String categoryId, List<CategoryAttribute> attrs) {
+        // 删除旧属性
+        this.remove(new LambdaQueryWrapper<CategoryAttribute>()
+                .eq(CategoryAttribute::getCategoryId, categoryId));
+        
+        // 保存新属性
+        if (attrs != null && !attrs.isEmpty()) {
+            for (int i = 0; i < attrs.size(); i++) {
+                CategoryAttribute attr = attrs.get(i);
+                attr.setAttrId(UUID.randomUUID().toString());
+                attr.setCategoryId(categoryId);
+                attr.setSortOrder(i);
+                this.save(attr);
+            }
+        }
+    }
+
+    @Override
+    @Transactional
+    public void deleteByCategoryId(String categoryId) {
+        this.remove(new LambdaQueryWrapper<CategoryAttribute>()
+                .eq(CategoryAttribute::getCategoryId, categoryId));
+    }
+}

src/main/java/com/example/building/service/impl/ProductAttributeServiceImpl.java

@@ -0,0 +1,54 @@
+package com.example.building.service.impl;
+
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
+import com.example.building.entity.ProductAttribute;
+import com.example.building.mapper.ProductAttributeMapper;
+import com.example.building.service.ProductAttributeService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * 商品属性服务实现
+ */
+@Service
+public class ProductAttributeServiceImpl implements ProductAttributeService {
+
+    @Override
+    public List<ProductAttribute> getByProductId(String productId) {
+        return this.list(new LambdaQueryWrapper<ProductAttribute>()
+                .eq(ProductAttribute::getProductId, productId));
+    }
+
+    @Override
+    @Transactional
+    public void saveProductAttributes(String productId, List<Map<String, Object>> attrs) {
+        // 删除旧属性
+        this.remove(new LambdaQueryWrapper<ProductAttribute>()
+                .eq(ProductAttribute::getProductId, productId));
+        
+        // 保存新属性
+        if (attrs != null && !attrs.isEmpty()) {
+            for (Map<String, Object> attr : attrs) {
+                ProductAttribute pa = new ProductAttribute();
+                pa.setId(UUID.randomUUID().toString());
+                pa.setProductId(productId);
+                pa.setAttrId((String) attr.get("attrId"));
+                pa.setAttrName((String) attr.get("attrName"));
+                pa.setAttrValue(String.valueOf(attr.get("attrValue")));
+                this.save(pa);
+            }
+        }
+    }
+
+    @Override
+    @Transactional
+    public void deleteByProductId(String productId) {
+        this.remove(new LambdaQueryWrapper<ProductAttribute>()
+                .eq(ProductAttribute::getProductId, productId));
+    }
+}