Java11优雅实现在一段时间内等待某个结果

比如有个需求，超时30秒，检查是否准备好，某个条件是否为真，30秒后也算条件为假，比较传统的做法是，每一秒检查，中间用Thread.sleep停一下

boolean checkResult = false;
for (int i = 0; i < 30; i++) {
    if (condition()) {//某种条件下判断为真，表示已经准备好
         checkResult = true;
          break;
    }
    Thread.sleep(1000L);
}
System.out.println(checkResult);

这样不是很优雅，且容易阻塞线程

Java8以上可以利用

private void test() throws Exception {
   CompletableFuture<Boolean> future = CompletableFuture.supplyAsync(this::condition)
                .completeOnTimeout(false, 30, TimeUnit.SECONDS);
   System.out.println(future.get());
}

public boolean condition() {
   //这里是比较耗时的操作，可能30秒内不返回
   return true;
}

public class LimitedTimeCondition {
    private final CountDownLatch conditionMetLatch;
    private final Integer timeoutSeconds;

    public LimitedTimeCondition(final Integer timeoutSeconds) {
        conditionMetLatch = new CountDownLatch(1);
        this.timeoutSeconds = timeoutSeconds;
    }

    public boolean waitForConditionToBeMet() {
        try {
            return conditionMetLatch.await(timeoutSeconds, TimeUnit.SECONDS);
        } catch (final InterruptedException e) {
            //被打断了
            return false;
        }
    }

    public void conditionWasMet() {
        conditionMetLatch.countDown();
    }

}

LimitedTimeCondition condition = new LimitedTimeCondition(30);
//在其他方法，适当的时候，调用condition.conditionWasMet();
if (condition.waitForConditionToBeMet()) {
//成功
} else {
//30秒超时不成功
}