如果它没有在 5 秒内完成,我想启动一个线程并取消它:
private final class HelloWorker implements Callable<String> {
public String call() throws Exception {
while(true) {
if (Thread.isInterrupted()) {
return null;
}
}
return performExpensiveComputation();
}
private String performExpensiveComputation() {
// some blocking expensive computation that may or may not take a very long time
}
}
private ExecutorService executorService = Executors.newFixedThreadPool(threadPoolSize);
Future<String> future = executorService.submit(new HelloWorker());
try {
String s = future.get(5, TimeUnit.SECONDS);
} catch (TimeoutException e) {
future.cancel(true);
System.out.println("cancelled: " + future.isCancelled() + "done: " + future.isDone());
executorService.shutdown();
try {
System.out.println("try to terminate: " + executorService.awaitTermination(60, TimeUnit.SECONDS));
} catch (Exception ex) {
// ignore
}
}
但是,awaitTermination 似乎返回 false。有没有办法让我检查为什么 ExecutorService 不会终止?我可以弄清楚哪些线程仍在运行吗?