package thread;

import java.util.concurrent.Callable;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.FutureTask;

public class App {

    public static class MySum implements Callable<Integer> {

        @Override

        public Integer call() throws Exception {

            System.out.println("准备计算");

            Thread.sleep(2000);

            int sum = 0;

            for (int i = 0; i < 5000; i++) {

                sum += i;

            }

            System.out.println("计算结果:" + sum);

            return sum;

        }

    }

    public static void main(String[] args) throws InterruptedException, ExecutionException {

        MySum mysum=new MySum();

        FutureTask<Integer> futureTask=new FutureTask<>(mysum);

        new Thread(futureTask).start();

        System.out.println("主线程的最终结果是:"+futureTask.get());

    }

}