Java利用Redis实现高并发计数器的示例代码

 /**
 * 是否拒绝服务
 * @return
 */
 private boolean denialOfService(String userId){
 long count=JedisUtil.setIncr(DateUtil.getDate()+"&"+userId+"&"+"queryCarViolation", 86400);
 if(count<=10){
  return false;
 }
 return true;
 }

    /**
 * 查询违章
 * @param plateNumber车牌
 * @param vin 车架号
 * @param engineNo发动机
 * @param request
 * @param response
 * @throws Exception
 */
 @RequestMapping("/queryCarViolationList.json")
 @AuthorizationApi
 public void queryCarViolationList(@CurrentToken Token token,String plateNumber,String vin,
    String engineNo,HttpServletRequest request,HttpServletResponse response) throws Exception {
   String userId=token.getUserId();
      //超过限制，拦截请求
   if(denialOfService(userId)){
  apiData(request, response, ReqJson.error(CarError.ONLY_5_TIMES_A_DAY_CAN_BE_FOUND));
  return;
   }
 //没超过限制，业务逻辑……
 }

public class JedisUtil {
 protected final static Logger logger = Logger.getLogger(JedisUtil.class);
 private static JedisPool jedisPool;
 
 @Autowired(required = true)
 public void setJedisPool(JedisPool jedisPool) {
 JedisUtil.jedisPool = jedisPool;
 }
 /**
 * 对某个键的值自增
 * @author liboyi
 * @param key 键
 * @param cacheSeconds 超时时间，0为不超时
 * @return
 */
 public static long setIncr(String key, int cacheSeconds) {
 long result = 0;
 Jedis jedis = null;
 try {
  jedis = jedisPool.getResource();
  result =jedis.incr(key);
  if (result<=1 && cacheSeconds != 0) {
  jedis.expire(key, cacheSeconds);
  }
  logger.debug("set "+ key + " = " + result);
 } catch (Exception e) {
  logger.warn("set "+ key + " = " + result);
 } finally {
  jedisPool.returnResource(jedis);
 }
 return result;
 }
}