ThreadPoolExecutor的PriorityBlockingQueue的cannot be cast to问题

一、异常信息：

java.lang.ClassCastException: java.util.concurrent.FutureTask cannot be cast to java.lang.Comparable
        at java.util.concurrent.PriorityBlockingQueue.siftUpComparable(PriorityBlockingQueue.java:357)
        at java.util.concurrent.PriorityBlockingQueue.offer(PriorityBlockingQueue.java:489)

二、代码信息

private static ExecutorService executorService = new ThreadPoolExecutor(CORE_POOL_SIZE, MAX_POOL_SIZE,
        60L, TimeUnit.SECONDS, new PriorityBlockingQueue<Runnable>(1024));

    executorService.execute(new Runnable() {
        @Override
        public void run() {
            .....
        }
    }

三、解决方法

executorService.execute(new TestTask());
class TestTask implements Comparable,Runnable{
    .....
}