首先MiaoshaController類，因為生成訂單之前要進行秒殺。其中，@RequestParam是獲取表單提交的name屬性中value

①判斷秒殺商品的庫存。

MiaoshaController:

GoodsVo goodsVo = goodsService.getOneGoodsVoById(goodsId);
int stockCount = goodsVo.getStockCount();
if(stockCount <= 0){
model.addAttribute("errmsg", CodeMsg.MIAO_SHA_OVER.getMsg());
return "miaosha_fail";
}

GoodsService:

public GoodsVo getOneGoodsVoById(long goodsId) {
return goodsDao.getOneGoodsVoById(goodsId);

}

GoodsDao:

@Select("select g.*, mg.stock_count, mg.miaosha_price, mg.start_date, mg.end_date from miaosha_goods mg left join goods g on mg.goods_id = g.id where mg.goods_id = #{id}")

public GoodsVo getOneGoodsVoById(@Param("id")long goodsId);

②防止重複秒殺

MiaoshaController:

//防止一個人秒殺多個商品，判斷是否已經秒殺到了  ==> 到OrderService中去查詢(查詢生成的秒殺型別的訂單，這種訂單必須是一個使用者和一個特價商品關聯產生的，且每個使用者只能產生一個)

}

OrderService:

public MiaoshaOrder getMiaoshaOrderByUserIdGoodsId(Long userId, long goodsId) {
return orderDao.getMiaoshaOrderByUserIdGoodsId(userId, goodsId);

}

OrderDao:

@Select("select * from miaosha_order where user_id= #{id} and goods_id=#{goodsId}")

public MiaoshaOrder getMiaoshaOrderByUserIdGoodsId(@Param("id")Long id, @Param("goodsId")long goodsId);

③//減庫存，（需要在一個事務當中去做，搞一個service，做一個MiaoshaService，然後進行一個Transaction操作）

OrderInfo orderInfo = miaoshaService.miaosha(user, goodsVo);//為什麼成功了以後要返回訂單呢？因為我們想秒殺成功之後直接進入到訂單詳情頁

@Transactional
public OrderInfo miaosha(MiaoshaUser user, GoodsVo goodsVo) {
//減庫存(減miaosha_goods的庫存)， 寫入秒殺訂單
goodsService.reduceStock(goodsVo);
//下訂單， 包含兩步：一、order_info  二、miaosha_order  實際上是兩步操作
return orderService.createOrder(user, goodsVo);

}

GoodsService:

public void reduceStock(GoodsVo goodsVo) {
//MiaoshaGoods mg = new MiaoshaGoods();
//mg.setGoodsId(goodsVo.getId());
goodsDao.reduceStock(goodsVo.getId());

}

GoodsDao:

@Update("update miaosha_goods set stock_count=stock_count-1 where goods_id = #{goods_id}")

public void reduceStock(@Param("goods_id")long goods_id);

④下(寫)訂單，寫入秒殺訂單

OrderService:

@Transactional
public OrderInfo createOrder(MiaoshaUser user, GoodsVo goodsVo) {
OrderInfo orderInfo = new OrderInfo();
orderInfo.setCreateDate(new Date());
orderInfo.setDeliveryAddrId(0L);
orderInfo.setGoodsCount(1);//本訂單購買商品的數量
orderInfo.setGoodsId(goodsVo.getId());
orderInfo.setGoodsName(goodsVo.getGoodsName());
orderInfo.setGoodsPrice(goodsVo.getMiaoshaPrice());
orderInfo.setOrderChannel(1);
orderInfo.setPayDate(new Date());
orderInfo.setStatus(0);
orderInfo.setUserId(user.getId());
long orderId = orderDao.insertOrderInfo(orderInfo);
MiaoshaOrder miaoshaOrder = new MiaoshaOrder();
miaoshaOrder.setGoodsId(goodsVo.getId());
miaoshaOrder.setOrderId(orderId);
miaoshaOrder.setUserId(user.getId());
//miaoshaOrder.setId(id);//這裡對id不需要進行設定
orderDao.insertMiaoshaOrder(miaoshaOrder);
return orderInfo;//最終返回的是orderInfo

}

OrderDao:   從形參傳遞進來的javaBean，在使用的時候直接${...}即可取出。

@Insert("insert into order_info(user_id, goods_id, goods_name, goods_count, goods_price, order_channel, status, create_date) values(#{userId},"
+ " #{goodsId}, #{goodsName}, #{goodsCount}, #{goodsPrice}, #{orderChannel}, #{status}, #{createDate})")
@SelectKey(keyColumn="id", keyProperty="id", resultType=long.class, before=false, statement="select last_insert_id()")
public long insertOrderInfo(OrderInfo orderInfo);

@Insert("insert into miaosha_order(user_id, order_id, goods_id) values(#{userId},#{orderId},#{goodsId})")
public int insertMiaoshaOrder(MiaoshaOrder miaoshaOrder);