public class Test {
    public static void main(String[] args) {
        //第一種方式
        ExecutorService executor = Executors.newCachedThreadPool();
        Task task = new Task();
        FutureTask<Integer> futureTask = new FutureTask<Integer>(task);
        executor.submit(futureTask);
        executor.shutdown();
         
        //第二種方式，注意這種方式和第一種方式效果是類似的，只不過一個使用的是ExecutorService，一個使用的是Thread
        /*Task task = new Task();
        FutureTask<Integer> futureTask = new FutureTask<Integer>(task);
        Thread thread = new Thread(futureTask);
        thread.start();*/
         
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e1) {
            e1.printStackTrace();
        }
         
        System.out.println("主執行緒在執行任務");
         
        try {
            System.out.println("task執行結果"+futureTask.get());
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
         
        System.out.println("所有任務執行完畢");
    }
}
class Task implements Callable<Integer>{
    @Override
    public Integer call() throws Exception {
        System.out.println("子執行緒在進行計算");
        Thread.sleep(3000);
        int sum = 0;
        for(int i=0;i<100;i++)
            sum += i;
        return sum;
    }
}