利用CountDownLatch实现并行计算

import java.util.concurrent.CountDownLatch;

/**
 * @Author pipi
 * @Date 2018/10/15 13:56
 **/
public class ParallelComputing {
    private int[] nums;
    private String[] info;
    private CountDownLatch countDownLatch;

    public ParallelComputing(String[] info) {
        this.info = info;
        int size = info.length;
        nums = new int[size];
        this.countDownLatch = new CountDownLatch(size);
    }

    public void calc(String line, int index) throws InterruptedException {
        String[] numbers = line.split(",");
        int total = 0;
        for (String num : numbers) {
            total += Integer.parseInt(num);
        }
        Thread.sleep(5000);
        nums[index] = total;
        countDownLatch.countDown();
        System.out.println(Thread.currentThread().getName() + "执行计算任务..." + line + ",结果为：" + total);
    }

    public void sum() {
        System.out.println("汇总线程开始执行...");
        int total = 0;
        for (int i : nums) {
            total += i;
        }
        System.out.println("汇总线程结束执行...结果为：" + total);
    }

    public void calcSum() throws InterruptedException {
        int size = info.length;
        for (int i = 0; i < size; i++) {
            final int j = i;
            new Thread(() -> {
                try {
                    calc(info[j], j);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }).start();
        }
        countDownLatch.await();
        sum();
    }

    public static void main(String[] args) throws InterruptedException {
        long start = System.currentTimeMillis();
        String[] info = {
                "2,22",
                "3,33",
                "232,32,76,84",
                "99,45,1"
        };
        ParallelComputing parallelComputing = new ParallelComputing(info);
        parallelComputing.calcSum();
        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }
}