FutureTask异步任务，超时打断执行

package com.louis.z.ifs.demo;

import java.util.concurrent.*;

public class Test {
    public static void main(String[] args) {
        try {
            ThreadPoolExecutor pool = (ThreadPoolExecutor) Executors.newFixedThreadPool(1);
            FutureTask<Long> futureTask = (FutureTask<Long>) pool.submit(new Callable<Long>() {
                @Override
                public Long call() throws Exception {
                    long s = System.currentTimeMillis();
                    System.out.println("Callable Start");
                    while (!Thread.currentThread().isInterrupted()) {
                        if (System.currentTimeMillis() - s > 4000) {
                            System.out.println("Callable break;");
                            break;
                        }
                    }
                    System.out.println("Callable Over");
                    return System.currentTimeMillis() - s;
                }
            });
            try {
                Long r = futureTask.get(3, TimeUnit.SECONDS);
                System.out.println("用时:" + r);
            } catch (InterruptedException | ExecutionException | TimeoutException e) {
                futureTask.cancel(true);
                System.out.println("futureTask cancel");
            } finally {
                pool.shutdown();
                System.out.println("finally");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}