淘东电商项目（78） -秒杀系统（服务保护）

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
</dependency>

/**
 * description: 服务限流
 * create by: YangLinWei
 * create time: 2020/5/26 3:00 下午
 */
@Component
@Slf4j
public class CurrentLimitHandler extends BaseHandler implements GatewayHandler {
    private RateLimiter rateLimiter = RateLimiter.create(1);
    @Autowired
    private GenerateToken generateToken;
    @Override
    public Boolean service(RequestContext ctx, String ipAddres, HttpServletRequest request, HttpServletResponse response) {
        // 1.用户限流频率设置 每秒中限制1个请求
        boolean tryAcquire = rateLimiter.tryAcquire(0, TimeUnit.SECONDS);
        if (!tryAcquire) {
            resultError(ctx, "There are too many people snapping up goods now. Please wait a moment!");
            return Boolean.FALSE;
        }
        // 2.使用redis限制用户访问频率
        String seckillId = request.getParameter("seckillId");
        String seckillToken = generateToken.getListKeyToken(seckillId + "");
        if (StringUtils.isEmpty(seckillToken)) {
            log.info(">>>seckillId:{}, The second kill has sold out, please come again next time!", seckillId);
            resultError(ctx, "The second kill has sold out, please come again next time!");
            return Boolean.FALSE;
        }
        if (gatewayHandler != null) {
            gatewayHandler.service(ctx, ipAddres, request, response);
        }
        return Boolean.TRUE;
    }
}

public class FactoryHandler {
    public static GatewayHandler getHandler() {
        // 1.黑名单拦截
        GatewayHandler handler1 = (GatewayHandler) SpringContextUtil.getBean("blackListHandler");
        // 2.API接口参数接口验签
        GatewayHandler handler2 = (GatewayHandler) SpringContextUtil.getBean("verifySignHandler");
        handler1.setNextHandler(handler2);
        // 3.参数过滤
        GatewayHandler handler3 = (GatewayHandler) SpringContextUtil.getBean("filterParamHandler");
        handler1.setNextHandler(handler3);
        //4.服务限流
        GatewayHandler handler4 = (GatewayHandler) SpringContextUtil.getBean("currentLimitHandler");
        handler3.setNextHandler(handler4);
        //5.验证accessToken
        GatewayHandler handler5 = (GatewayHandler) SpringContextUtil.getBean("apiAuthorityHandler");
        handler4.setNextHandler(handler5);
        return handler1;
    }
}

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>

@Override
@Transactional
@HystrixCommand(fallbackMethod = "spikeFallback")
public BaseResponse<JSONObject> spike(String phone, Long seckillId) {
  // 1.参数验证
  if (StringUtils.isEmpty(phone)) {
    return setResultError("手机号码不能为空!");
  }
  if (seckillId == null) {
    return setResultError("商品库存id不能为空!");
  }
  // 2.从redis从获取对应的秒杀token
  String seckillToken = generateToken.getListKeyToken(seckillId + "");
  if (StringUtils.isEmpty(seckillToken)) {
    log.info(">>>seckillId:{}, 亲，该秒杀已经售空，请下次再来!", seckillId);
    return setResultError("亲，该秒杀已经售空，请下次再来!");
  }
  // 3.获取到秒杀token之后，异步放入mq中实现修改商品的库存
  sendSeckillMsg(seckillId, phone);
  return setResultSuccess("正在排队中.......");
}
private BaseResponse<JSONObject> spikeFallback(String phone, Long seckillId) {
  return setResultError("服务器忙,请稍后重试!");
}