如何操作Redis和zookeeper實現(xiàn)分布式鎖

setnx(key,value) 如果key不存在，設(shè)置為當(dāng)前key的值為value;如果key存在，直接返回。
expire()來設(shè)置超時時間

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Lockable{
  // redis緩存key
  String key();
  // redis緩存key中的數(shù)據(jù)
  String value() default "";
  // 過期時間(秒)，默認為一分鐘
  long expire() default 60;
}

 @Lockable(key = "DistributedLock:dealExpireRecords")
 public void dealExpireRecords() {
 }

@Component
@Slf4j
@Aspect
public class LockAspect {

  @Autowired
  private RedisTemplate redisTemplate;

  @Around("@annotation(com.records.aop.Lockable)")
  public Object distributeLock(ProceedingJoinPoint pjp) {
    Object resultObject = null;

    //確認此注解是用在方法上
    Signature signature = pjp.getSignature();
    if (!(signature instanceof MethodSignature)) {
      log.error("Lockable is method annotation!");
      return resultObject;
    }

    MethodSignature methodSignature = (MethodSignature) signature;
    Method targetMethod = methodSignature.getMethod();

    //獲取注解信息
    Lockable lockable = targetMethod.getAnnotation(Lockable.class);
    String key = lockable.key();
    String value = lockable.value();
    long expire = lockable.expire();

    // 分布式鎖，如果沒有此key，設(shè)置此值并返回true；如果有此key，則返回false
    boolean result = redisTemplate.boundValueOps(key).setIfAbsent(value);
    if (!result) {
      //其他程序已經(jīng)獲取分布式鎖
      return resultObject;
    }

    //設(shè)置過期時間，默認一分鐘
    redisTemplate.boundValueOps(key).expire(expire, TimeUnit.SECONDS);

    try {
      resultObject = pjp.proceed(); //調(diào)用對應(yīng)方法執(zhí)行
    } catch (Throwable throwable) {
      throwable.printStackTrace();
    }
    return resultObject;
  }
}