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一、锁定
基于Redis的Java分布式可重入锁对象,并实现了锁接口。
如果获取锁的Redisson实例崩溃,则此类锁可能会在获取状态下永久挂起。为了避免这种Redisson维护锁看门狗,当锁持有者Redisson实例处于活动状态时,它会延长锁的到期时间。默认情况下,锁看门狗超时为30秒,可以通过Config.lockWatchdogTimeout设置进行更改。
可以定义锁获取期间的leaseTime参数。在指定的时间间隔后,锁定的锁将自动释放。
RLock对象的行为符合Java Lock规范。这意味着只有锁所有者线程才能解锁它,否则将引发IllegalMonitorStateException。否则,请考虑使用RSemaphore对象。
代码示例:
RLock lock = redisson.getLock("myLock");// traditional lock method
lock.lock();// or acquire lock and automatically unlock it after 10 seconds
lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
boolean res = lock.tryLock(100, 10, TimeUnit.SECONDS);
if (res) {try {...} finally {lock.unlock();}
}
异步接口用法的代码示例:
RLock lock = redisson.getLock("myLock");RFuture<Void> lockFuture = lock.lockAsync();// or acquire lock and automatically unlock it after 10 seconds
RFuture<Void> lockFuture = lock.lockAsync(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
RFuture<Boolean> lockFuture = lock.tryLockAsync(100, 10, TimeUnit.SECONDS);lockFuture.whenComplete((res, exception) -> {// ...lock.unlockAsync();
});
反应式接口用法的代码示例:
RedissonReactiveClient redisson = redissonClient.reactive();
RLockReactive lock = redisson.getLock("myLock");Mono<Void> lockMono = lock.lock();// or acquire lock and automatically unlock it after 10 seconds
Mono<Void> lockMono = lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Mono<Boolean> lockMono = lock.tryLock(100, 10, TimeUnit.SECONDS);lockMono.doOnNext(res -> {// ...
})
.doFinally(lock.unlock())
.subscribe();
RxJava3 接口使用的代码示例:
RedissonRxClient redisson = redissonClient.rxJava();
RLockRx lock = redisson.getLock("myLock");Completable lockRes = lock.lock();// or acquire lock and automatically unlock it after 10 seconds
Completable lockRes = lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Single<Boolean> lockRes = lock.tryLock(100, 10, TimeUnit.SECONDS);lockRes.doOnSuccess(res -> {// ...
})
.doFinally(lock.unlock())
.subscribe();
二、公平锁定
基于Redis的分布式可重入公平Java锁对象实现了锁接口。
公平锁保证线程将按照请求的顺序获取它。所有等待的线程都将排队,如果某个线程已死亡,Redisson将等待其返回5秒。例如,如果5个线程由于某种原因而死亡,那么延迟将为25秒。
如果获取锁的Redisson实例崩溃,则此类锁可能会在获取状态下永久挂起。为了避免这种Redisson维护锁看门狗,当锁持有者Redisson实例处于活动状态时,它会延长锁的到期时间。默认情况下,锁看门狗超时为30秒,可以通过Config.lockWatchdogTimeout设置进行更改。
可以定义锁获取期间的leaseTime参数。在指定的时间间隔后,锁定的锁将自动释放。
RLock对象的行为符合Java Lock规范。这意味着只有锁所有者线程才能解锁它,否则将引发IllegalMonitorStateException。否则,请考虑使用RSemaphore对象。
代码示例:
RLock lock = redisson.getFairLock("myLock");// traditional lock method
lock.lock();// or acquire lock and automatically unlock it after 10 seconds
lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
boolean res = lock.tryLock(100, 10, TimeUnit.SECONDS);
if (res) {try {...} finally {lock.unlock();}
}
异步接口用法的代码示例:
RLock lock = redisson.getFairLock("myLock");RFuture<Void> lockFuture = lock.lockAsync();// or acquire lock and automatically unlock it after 10 seconds
RFuture<Void> lockFuture = lock.lockAsync(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
RFuture<Boolean> lockFuture = lock.tryLockAsync(100, 10, TimeUnit.SECONDS);lockFuture.whenComplete((res, exception) -> {// ...lock.unlockAsync();
});
Reactive接口 用法的代码示例:
RedissonReactiveClient redisson = redissonClient.reactive();
RLockReactive lock = redisson.getFairLock("myLock");Mono<Void> lockMono = lock.lock();// or acquire lock and automatically unlock it after 10 seconds
Mono<Void> lockMono = lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Mono<Boolean> lockMono = lock.tryLock(100, 10, TimeUnit.SECONDS);lockMono.doOnNext(res -> {// ...
})
.doFinally(lock.unlock())
.subscribe();
RxJava3 接口使用的代码示例:
RedissonRxClient redisson = redissonClient.rxJava();
RLockRx lock = redisson.getFairLock("myLock");Completable lockRes = lock.lock();// or acquire lock and automatically unlock it after 10 seconds
Completable lockRes = lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Single<Boolean> lockRes = lock.tryLock(100, 10, TimeUnit.SECONDS);lockRes.doOnSuccess(res -> {// ...
})
.doFinally(lock.unlock())
.subscribe();
三、多重锁
基于Redis的分布式MultiLock对象允许将Lock对象分组,并将其作为单个锁处理。每个RLock对象可能属于不同的Redisson实例。
如果获取MultiLock的Redisson实例崩溃,那么这样的MultiLock可能会永远挂在获取状态。为了避免这种Redisson维护锁看门狗,当锁持有者Redisson实例处于活动状态时,它会延长锁的到期时间。默认情况下,锁看门狗超时为30秒,可以通过Config.lockWatchdogTimeout设置进行更改。
可以定义锁获取期间的leaseTime参数。在指定的时间间隔后,锁定的锁将自动释放。
MultiLock对象的行为符合Java Lock规范。这意味着只有锁所有者线程才能解锁它,否则将引发IllegalMonitorStateException。否则,请考虑使用RSemaphore对象。
代码示例:
RLock lock1 = redisson1.getLock("lock1");
RLock lock2 = redisson2.getLock("lock2");
RLock lock3 = redisson3.getLock("lock3");RLock multiLock = anyRedisson.getMultiLock(lock1, lock2, lock3);// traditional lock method
multiLock.lock();// or acquire lock and automatically unlock it after 10 seconds
multiLock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
boolean res = multiLock.tryLock(100, 10, TimeUnit.SECONDS);
if (res) {try {...} finally {multiLock.unlock();}
}
异步接口用法的代码示例:
RLock lock1 = redisson1.getLock("lock1");
RLock lock2 = redisson2.getLock("lock2");
RLock lock3 = redisson3.getLock("lock3");RLock multiLock = anyRedisson.getMultiLock(lock1, lock2, lock3);RFuture<Void> lockFuture = multiLock.lockAsync();// or acquire lock and automatically unlock it after 10 seconds
RFuture<Void> lockFuture = multiLock.lockAsync(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
RFuture<Boolean> lockFuture = multiLock.tryLockAsync(100, 10, TimeUnit.SECONDS);lockFuture.whenComplete((res, exception) -> {// ...multiLock.unlockAsync();
});
反应式接口用法的代码示例:
RedissonReactiveClient anyRedisson = redissonClient.reactive();RLockReactive lock1 = redisson1.getLock("lock1");
RLockReactive lock2 = redisson2.getLock("lock2");
RLockReactive lock3 = redisson3.getLock("lock3");RLockReactive multiLock = anyRedisson.getMultiLock(lock1, lock2, lock3);Mono<Void> lockMono = multiLock.lock();// or acquire lock and automatically unlock it after 10 seconds
Mono<Void> lockMono = multiLock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Mono<Boolean> lockMono = multiLock.tryLock(100, 10, TimeUnit.SECONDS);lockMono.doOnNext(res -> {// ...
})
.doFinally(multiLock.unlock())
.subscribe();
RxJava3 接口使用的代码示例:
RedissonRxClient anyRedisson = redissonClient.rxJava();RLockRx lock1 = redisson1.getLock("lock1");
RLockRx lock2 = redisson2.getLock("lock2");
RLockRx lock3 = redisson3.getLock("lock3");RLockRx multiLock = anyRedisson.getMultiLock(lock1, lock2, lock3);Completable lockRes = multiLock.lock();// or acquire lock and automatically unlock it after 10 seconds
Completable lockRes = multiLock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Single<Boolean> lockRes = multiLock.tryLock(100, 10, TimeUnit.SECONDS);lockRes.doOnSuccess(res -> {// ...
})
.doFinally(multiLock.unlock())
.subscribe();
四、读写锁定
基于Redis的Java分布式可重入读写锁对象实现了读写锁接口。读和写锁都实现RLock接口。
只允许有多个ReadLock所有者和一个WriteLock所有者。
如果获取锁的Redisson实例崩溃,则此类锁可能会在获取状态下永久挂起。为了避免这种Redisson维护锁看门狗,当锁持有者Redisson实例处于活动状态时,它会延长锁的到期时间。默认情况下,锁看门狗超时为30秒,可以通过Config.lockWatchdogTimeout设置进行更改。
此外,Redisson允许在获取锁期间指定leaseTime参数。在指定的时间间隔后,锁定的锁将自动释放。
RLock对象的行为符合Java Lock规范。这意味着只有锁所有者线程才能解锁它,否则将引发IllegalMonitorStateException。否则,请考虑使用RSemaphore对象。
代码示例:
RReadWriteLock rwlock = redisson.getReadWriteLock("myLock");RLock lock = rwlock.readLock();
// or
RLock lock = rwlock.writeLock();// traditional lock method
lock.lock();// or acquire lock and automatically unlock it after 10 seconds
lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
boolean res = lock.tryLock(100, 10, TimeUnit.SECONDS);
if (res) {try {...} finally {lock.unlock();}
}
异步接口用法的代码示例:
RReadWriteLock rwlock = redisson.getReadWriteLock("myLock");RLock lock = rwlock.readLock();
// or
RLock lock = rwlock.writeLock();RFuture<Void> lockFuture = lock.lockAsync();// or acquire lock and automatically unlock it after 10 seconds
RFuture<Void> lockFuture = lock.lockAsync(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
RFuture<Boolean> lockFuture = lock.tryLockAsync(100, 10, TimeUnit.SECONDS);lockFuture.whenComplete((res, exception) -> {// ...lock.unlockAsync();
});
反应式接口用法的代码示例:
RedissonReactiveClient redisson = redissonClient.reactive();RReadWriteLockReactive rwlock = redisson.getReadWriteLock("myLock");RLockReactive lock = rwlock.readLock();
// or
RLockReactive lock = rwlock.writeLock();Mono<Void> lockMono = lock.lock();// or acquire lock and automatically unlock it after 10 seconds
Mono<Void> lockMono = lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Mono<Boolean> lockMono = lock.tryLock(100, 10, TimeUnit.SECONDS);lockMono.doOnNext(res -> {// ...
})
.doFinally(lock.unlock())
.subscribe();
RxJava3 接口使用的代码示例:
RedissonRxClient redisson = redissonClient.rxJava();RReadWriteLockRx rwlock = redisson.getReadWriteLock("myLock");RLockRx lock = rwlock.readLock();
// or
RLockRx lock = rwlock.writeLock();Completable lockRes = lock.lock();// or acquire lock and automatically unlock it after 10 seconds
Completable lockRes = lock.lock(10, TimeUnit.SECONDS);// or wait for lock aquisition up to 100 seconds
// and automatically unlock it after 10 seconds
Single<Boolean> lockRes = lock.tryLock(100, 10, TimeUnit.SECONDS);lockRes.doOnSuccess(res -> {// ...
})
.doFinally(lock.unlock())
.subscribe();
五、信号量
基于Redis的分布式Java信号量对象,类似于信号量对象。
可以在使用前初始化,但这不是必需的,通过trySetPermissions(permissions)方法获得可用的许可量。
代码示例:
RSemaphore semaphore = redisson.getSemaphore("mySemaphore");// acquire single permit
semaphore.acquire();// or acquire 10 permits
semaphore.acquire(10);// or try to acquire permit
boolean res = semaphore.tryAcquire();// or try to acquire permit or wait up to 15 seconds
boolean res = semaphore.tryAcquire(15, TimeUnit.SECONDS);// or try to acquire 10 permit
boolean res = semaphore.tryAcquire(10);// or try to acquire 10 permits or wait up to 15 seconds
boolean res = semaphore.tryAcquire(10, 15, TimeUnit.SECONDS);
if (res) {try {...} finally {semaphore.release();}
}
异步接口用法的代码示例:
RSemaphore semaphore = redisson.getSemaphore("mySemaphore");// acquire single permit
RFuture<Void> acquireFuture = semaphore.acquireAsync();// or acquire 10 permits
RFuture<Void> acquireFuture = semaphore.acquireAsync(10);// or try to acquire permit
RFuture<Boolean> acquireFuture = semaphore.tryAcquireAsync();// or try to acquire permit or wait up to 15 seconds
RFuture<Boolean> acquireFuture = semaphore.tryAcquireAsync(15, TimeUnit.SECONDS);// or try to acquire 10 permit
RFuture<Boolean> acquireFuture = semaphore.tryAcquireAsync(10);// or try to acquire 10 permits or wait up to 15 seconds
RFuture<Boolean> acquireFuture = semaphore.tryAcquireAsync(10, 15, TimeUnit.SECONDS);acquireFuture.whenComplete((res, exception) -> {// ...semaphore.releaseAsync();
});
反应式接口用法的代码示例:
RedissonReactiveClient redisson = redissonClient.reactive();RSemaphoreReactive semaphore = redisson.getSemaphore("mySemaphore");// acquire single permit
Mono<Void> acquireMono = semaphore.acquire();// or acquire 10 permits
Mono<Void> acquireMono = semaphore.acquire(10);// or try to acquire permit
Mono<Boolean> acquireMono = semaphore.tryAcquire();// or try to acquire permit or wait up to 15 seconds
Mono<Boolean> acquireMono = semaphore.tryAcquire(15, TimeUnit.SECONDS);// or try to acquire 10 permit
Mono<Boolean> acquireMono = semaphore.tryAcquire(10);// or try to acquire 10 permits or wait up to 15 seconds
Mono<Boolean> acquireMono = semaphore.tryAcquire(10, 15, TimeUnit.SECONDS);acquireMono.doOnNext(res -> {// ...
})
.doFinally(semaphore.release())
.subscribe();
RxJava3 接口使用的代码示例:
RedissonRxClient redisson = redissonClient.rxJava();RSemaphoreRx semaphore = redisson.getSemaphore("mySemaphore");// acquire single permit
Completable acquireRx = semaphore.acquire();// or acquire 10 permits
Completable acquireRx = semaphore.acquire(10);// or try to acquire permit
Single<Boolean> acquireRx = semaphore.tryAcquire();// or try to acquire permit or wait up to 15 seconds
Single<Boolean> acquireRx = semaphore.tryAcquire(15, TimeUnit.SECONDS);// or try to acquire 10 permit
Single<Boolean> acquireRx = semaphore.tryAcquire(10);// or try to acquire 10 permits or wait up to 15 seconds
Single<Boolean> acquireRx = semaphore.tryAcquire(10, 15, TimeUnit.SECONDS);acquireRx.doOnSuccess(res -> {// ...
})
.doFinally(semaphore.release())
.subscribe();