一个同步队列例子

这个用的也比较少, 做一个参考, 原文见 这里

private BlockingQueue workQueue = new LinkedBlockingQueue();
private Map commandQueueMap = new ConcurrentHashMap(); 
 
public SynchronousQueue addCommand(Command command) {
    SynchronousQueue queue = new SynchronousQueue();
    commandQueueMap.put(command, queue);
    workQueue.offer(command);
    return queue;
}
 
public Object call() throws Exception {
    try {
        Command command = workQueue.take();
        Result result = command.execute();
        SynchronousQueue queue = commandQueueMap.get(command);
        queue.offer(result);
        return null;
    } catch (InterruptedException e) {
        throw new WorkException(e);
    }
}

Command command;
SynchronousQueue queue = commandRunner.addCommand(command);
Result result = queue.poll(2, TimeUnit.MINUTES);
if (result == null) {
	throw new CommandTooLongException(command);
} else {
	return result;
}