预定执行程序：以固定速率轮询结果，如果超时或结果有效，则退出

使它成为自调度任务。用伪代码：

public class PollingTaskRunner {...CountDownLatch doneWait = new CountDownLatch(1);volatile boolean done;PollingTaskRunner(Runnable pollingTask, int frequency, int period) {    ...    endTime = now + period;    executor.schedule(this, 0);}run() {    try {        pollingTask.run();    } catch (Exception e) {        ...    }    if (pollingTask.isComplete() || now + frequency > endTime) {        done = true;        doneWait.countDown();        executor.shutdown();    } else {        executor.schedule(this, frequency);    }}await() {    doneWait.await();}isDone() {    return done;}}

它并不复杂，但是在您第一次运行/测试时添加大量调试语句，以便您了解发生了什么。一旦按预期运行，就很容易重用该模式。