Queue.Poll() is return null but Queue.size() >0 in java queue

问题

My code:

while( Memo.qRcv.size() > 0) {
    MessageReceived msg=Memo.qRcv.poll();
    ...
}

Then I got

2014-03-01 11:09:36 DEBUG [Thread-16] (threadQueueSendtoUser.java:163) - Memo.qRcv = null, size = 41590

回答1:

I found solution by using ConcurrentLinkedQueue http://www.javacodex.com/Concurrency/ConcurrentLinkedQueue-Example

Problem here is I used 2 thread to process a Queue, should not use normal queue. I will feedback if any problem

Thank you all

来源：https://stackoverflow.com/questions/22112580/queue-poll-is-return-null-but-queue-size-0-in-java-queue