在库存服务中实现缓存与数据库双写一致性保障方案（二）

封装请求接口，第一个实现类，data数据更新的操作，比如一个商品发生了交易，就要修改商品对应的库存了，此时就

data update request，数据更新请求

1.删除缓存

2.更新数据库

实体类:

package com.roncoo.eshop.entity;

/**
 * 库存数量model
 * @author Administrator
 *
 */
public class ProductInventory {

  /**
   * 商品id
   */
  private Integer productId;
  /**
   * 库存数量
   */
  private Long inventoryCnt;

  public ProductInventory() {

  }

  public ProductInventory(Integer productId, Long inventoryCnt) {
    this.productId = productId;
    this.inventoryCnt = inventoryCnt;
  }

  public Integer getProductId() {
    return productId;
  }
  public void setProductId(Integer productId) {
    this.productId = productId;
  }
  public Long getInventoryCnt() {
    return inventoryCnt;
  }
  public void setInventoryCnt(Long inventoryCnt) {
    this.inventoryCnt = inventoryCnt;
  }

}

　　mapper:

package com.roncoo.eshop.dao;

import com.roncoo.eshop.entity.ProductInventory;
import org.apache.ibatis.annotations.Param;

public interface ProductInventoryMapper {

    /**
     * 更新库存数量
     * @param productInventory 商品库存
     */
    void updateProductInventory(ProductInventory productInventory);

    /**
     * 根据商品id查询商品库存信息
     * @param productId 商品id
     * @return 商品库存信息
     */
    ProductInventory findProductInventory(@Param("productId") Integer productId);
}

　　xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.roncoo.eshop.dao.ProductInventoryMapper">

    <update id="updateProductInventory" parameterType="com.roncoo.eshop.entity.ProductInventory">
    update product_inventory set inventory_cnt=#{inventoryCnt} where product_id=#{productId}
    </update>

    <select id="findProductInventory" resultType="com.roncoo.eshop.entity.ProductInventory">
      select product_id as "productId",inventory_cnt as "inventoryCnt" from
       product_inventory where product_id=#{productId}
    </select>

</mapper>

　　sql:

create table product_inventory
(
    product_id    int auto_increment
        primary key,
    inventory_cnt bigint(255) null
);

作者：​​三号小玩家​​​，转载请注明原文链接 ​