java----练习

利用线程池求和1+2+…+100;

要求：将任务分成10个部分，每个线程单独计算和，将最终的结果合并。

使用callable和future。

HomeWork.java

import java.util.ArrayList;
import java.util.concurrent.*;

public class HomeWork {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService pool = Executors.newSingleThreadExecutor();

        int sum1=0;
        ArrayList<Integer> list = new ArrayList<>();
        for (int i = 1; i < 100; i++) {
            int tmp=i;
            if(i%10==1){
                Future<Integer> future = pool.submit(new Callable<Integer>() {
                    @Override
                    public Integer call() throws Exception {
                        int sum = 0;
                        for (int j = tmp; j < tmp + 10; j++) {
                            sum += j;
                        }
                        return sum;
                    }
                });
                list.add(future.get());
            }
        }
        for (Integer num :
                list) {
            sum1 += num;
        }
        System.out.println(sum1);
    }
}