import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 防止同時提交注解
 */
@Target({ElementType.PARAMETER, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface NoRepeatCommit {
    // key的過期時間3s
    int expire() default 3;
}

@NoRepeatCommit
或者
@NoRepeatCommit(expire = 10)

@Aspect
public class NoRepeatSubmitAspect {
    private static Logger _log = LoggerFactory.getLogger(NoRepeatSubmitAspect.class);
    RedisLock redisLock = new RedisLock();

    @Pointcut("@annotation(com.zheng.common.annotation.NoRepeatCommit)")
    public void point() {}

    @Around("point()")
    public Object doAround(ProceedingJoinPoint pjp) throws Throwable {
        // 獲取request
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
        ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes) requestAttributes;
        HttpServletRequest request = servletRequestAttributes.getRequest();
        HttpServletResponse responese = servletRequestAttributes.getResponse();
        Object result = null;

        String account = (String) request.getSession().getAttribute(UpmsConstant.ACCOUNT);
        User user = (User) request.getSession().getAttribute(UpmsConstant.USER);
        if (StringUtils.isEmpty(account)) {
            return pjp.proceed();
        }

        MethodSignature signature = (MethodSignature) pjp.getSignature();
        Method method = signature.getMethod();
        NoRepeatCommit form = method.getAnnotation(NoRepeatCommit.class);

        String sessionId = request.getSession().getId() + "|" + user.getUsername();
        String url = ObjectUtils.toString(request.getRequestURL());
        String pg = request.getMethod();
        String key = account + "_" + sessionId + "_" + url + "_" + pg;
        int expire = form.expire();
        if (expire < 0) {
            expire = 3;
        }

        // 獲取鎖
        boolean isSuccess = redisLock.tryLock(key, key + sessionId, expire);
        // 獲取成功
        if (isSuccess) {
            // 執(zhí)行請求
            result = pjp.proceed();
            int status = responese.getStatus();
            _log.debug("status = {}" + status);
            // 釋放鎖，3s后讓鎖自動釋放，也可以手動釋放
            // redisLock.releaseLock(key, key + sessionId);
            return result;
        } else {
            // 失敗，認為是重復提交的請求
            return new UpmsResult(UpmsResultConstant.REPEAT_COMMIT, ValidationError.create(UpmsResultConstant.REPEAT_COMMIT.message));
        }
    }
}

/**
 * redis分布式鎖實現(xiàn)
 * Lua表達式為了保持數(shù)據(jù)的原子性
 */
public class RedisLock {

    /**
     * redis 鎖成功標識常量
     */
    private static final Long RELEASE_SUCCESS = 1L;
    private static final String SET_IF_NOT_EXIST = "NX";
    private static final String SET_WITH_EXPIRE_TIME = "EX";
    private static final String LOCK_SUCCESS= "OK";
    /**
     * 加鎖 Lua 表達式。
     */
    private static final String RELEASE_TRY_LOCK_LUA =
            "if redis.call('setNx',KEYS[1],ARGV[1]) == 1 then return redis.call('expire',KEYS[1],ARGV[2]) else return 0 end";
    /**
     * 解鎖 Lua 表達式.
     */
    private static final String RELEASE_RELEASE_LOCK_LUA =
            "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";

    /**
     * 加鎖
     * 支持重復，線程安全
     * 既然持有鎖的線程崩潰，也不會發(fā)生死鎖，因為鎖到期會自動釋放
     * @param lockKey    加鎖鍵
     * @param userId     加鎖客戶端唯一標識（采用用戶id, 需要把用戶 id 轉(zhuǎn)換為 String 類型）
     * @param expireTime 鎖過期時間
     * @return OK 如果key被設置了
     */
    public boolean tryLock(String lockKey, String userId, long expireTime) {
        Jedis jedis = JedisUtils.getInstance().getJedis();
        try {
            jedis.select(JedisUtils.index);
            String result = jedis.set(lockKey, userId, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, expireTime);
            if (LOCK_SUCCESS.equals(result)) {
                return true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (jedis != null)
                jedis.close();
        }

        return false;
    }

    /**
     * 解鎖
     * 與 tryLock 相對應，用作釋放鎖
     * 解鎖必須與加鎖是同一人，其他人拿到鎖也不可以解鎖
     *
     * @param lockKey 加鎖鍵
     * @param userId  解鎖客戶端唯一標識（采用用戶id, 需要把用戶 id 轉(zhuǎn)換為 String 類型）
     * @return
     */
    public boolean releaseLock(String lockKey, String userId) {
        Jedis jedis = JedisUtils.getInstance().getJedis();
        try {
            jedis.select(JedisUtils.index);
            Object result = jedis.eval(RELEASE_RELEASE_LOCK_LUA, Collections.singletonList(lockKey), Collections.singletonList(userId));
            if (RELEASE_SUCCESS.equals(result)) {
                return true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (jedis != null)
                jedis.close();
        }

        return false;
    }
}

/* Set the string value as value of the key. The string can't be longer than 1073741824 bytes (1 GB).
Params:
		key –
		value –
		nxxx – NX|XX, NX -- Only set the key if it does not already exist. XX -- Only set the 		key if it already exist.
		expx – EX|PX, expire time units: EX = seconds; PX = milliseconds
		time – expire time in the units of expx
Returns: Status code reply
*/
public String set(final String key, final String value, final String nxxx, final String expx,
      final long time) {
    checkIsInMultiOrPipeline();
    client.set(key, value, nxxx, expx, time);
    return client.getStatusCodeReply();
  }