秒杀代码核心部分

　　//内存标记，商品是否卖完
    private HashMap<Long, Boolean> localOverMap =  new HashMap<Long, Boolean>();
    
    /**
     * 系统初始化，加载商品库存，并为每个商品初始化内存标记
     * */
    public void afterPropertiesSet() throws Exception {  //该Controller实现InitializingBean
        List<GoodsVo> goodsList = goodsService.listGoodsVo();
        if(goodsList == null) {
            return;
        }
        for(GoodsVo goods : goodsList) {
            redisService.set(GoodsKey.getMiaoshaGoodsStock, ""+goods.getId(), goods.getStockCount());
            localOverMap.put(goods.getId(), false);
        }
    }
    
   　//这里使用pathVariable，为了拼接动态路径，也是一种防刷手段
　　 @RequestMapping(value="/{path}/do_miaosha", method=RequestMethod.POST)
    @ResponseBody
    public Result<Integer> miaosha(Model model,MiaoshaUser user,
            @RequestParam("goodsId")long goodsId,
            @PathVariable("path") String path) {
        model.addAttribute("user", user);
        if(user == null) {
            return Result.error(CodeMsg.SESSION_ERROR);
        }
        //验证path
        boolean check = miaoshaService.checkPath(user, goodsId, path);
        if(!check){
            return Result.error(CodeMsg.REQUEST_ILLEGAL);
        }
        //内存标记，减少redis访问，如果没有这一步，也可以，直接去预减库存，但是，会造成redis的负担，所以加一个非线程安全的map，去做一层简单过滤
        //同一时间，有可能100个人去抢最后一件商品（get为false），但是没关系，有redis的decr去做原子保障，保证不会超卖
        boolean over = localOverMap.get(goodsId);
        if(over) {
            return Result.error(CodeMsg.MIAO_SHA_OVER);
        }
　　　　　//开始主流程：预减库存->判断重复秒杀->加入消息队列，返回成功（即排队中）
        //预减库存
        long stock = redisService.decr(GoodsKey.getMiaoshaGoodsStock, ""+goodsId);//10
        if(stock < 0) {
             localOverMap.put(goodsId, true);
            redisService.set(GoodsKey.getMiaoshaGoodsStock, ""+goodsId,0);
            return Result.error(CodeMsg.MIAO_SHA_OVER);
        }
        //判断是否已经秒杀到了
        //redisService.set(OrderKey.getMiaoshaOrderByUidGid, ""+user.getId()+"_"+goods.getId(), miaoshaOrder);
        MiaoshaOrder order = orderService.getMiaoshaOrderByUserIdGoodsId(user.getId(), goodsId);
        if(order != null) {
            redisService.incr(GoodsKey.getMiaoshaGoodsStock, ""+goodsId);
            localOverMap.put(goodsId, false);
            return Result.error(CodeMsg.REPEATE_MIAOSHA);
        }
        //入队
        MiaoshaMessage mm = new MiaoshaMessage();
        mm.setUser(user);
        mm.setGoodsId(goodsId);
　　　　　//消息队列发送者，发送消息
        sender.sendMiaoshaMessage(mm);
        return Result.success(0);//排队中，用户点击秒杀后（内部去请求path，然后用path去请求秒杀服务，然后调轮询接口，查询结果）
      
    }
    
    /**做延迟任务setTimeOut，轮询秒杀结果
     * orderId：成功
     * -1：秒杀失败
     * 0： 排队中
     * */
    @RequestMapping(value="/result", method=RequestMethod.GET)
    @ResponseBody
    public Result<Long> miaoshaResult(Model model,MiaoshaUser user,
            @RequestParam("goodsId")long goodsId) {
        model.addAttribute("user", user);
        if(user == null) {
            return Result.error(CodeMsg.SESSION_ERROR);
        }
        long result  =miaoshaService.getMiaoshaResult(user.getId(), goodsId);
        return Result.success(result);
    }
    
    @AccessLimit(seconds=5, maxCount=5, needLogin=true)//自定义注解，接口防刷
    @RequestMapping(value="/path", method=RequestMethod.GET)//先获取path，才能请求秒杀接口
    @ResponseBody
    public Result<String> getMiaoshaPath(HttpServletRequest request, MiaoshaUser user,
            @RequestParam("goodsId")long goodsId,
            @RequestParam(value="verifyCode", defaultValue="0")int verifyCode
            ) {
        if(user == null) {
            return Result.error(CodeMsg.SESSION_ERROR);
        }
        boolean check = miaoshaService.checkVerifyCode(user, goodsId, verifyCode);
        if(!check) {
            return Result.error(CodeMsg.REQUEST_ILLEGAL);
        }
        String path = miaoshaService.createMiaoshaPath(user, goodsId);
        return Result.success(path);
    }
    
}