Sender. cancel Scheduled Message(long sequenceNumber) 方法
Cancels the enqueuing of an already sent scheduled message, if it was not already enqueued. This method blocks until the message is sent to the entity. Calling this method is equivalent to calling . For better performance, use async methods.
public void cancelScheduledMessage(long sequenceNumber)
sequence number of the scheduled message
if the current thread was interrupted while waiting
if scheduled message couldn't be cancelled