在Java中如何使用ForkJoinPool拆分大任务实现并行计算_并行计算实践方法

public class SumTask extends RecursiveTask<Long> {
    private static final int THRESHOLD = 1000; // 拆分阈值
    private long[] array;
    private int start, end;
<pre class='brush:java;toolbar:false;'>public SumTask(long[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
}

@Override
protected Long compute() {
    if (end - start <= THRESHOLD) {
        // 小任务直接计算
        long sum = 0;
        for (int i = start; i < end; i++) {
            sum += array[i];
        }
        return sum;
    } else {
        // 拆分为两个子任务
        int mid = (start + end) / 2;
        SumTask left = new SumTask(array, start, mid);
        SumTask right = new SumTask(array, mid, end);

        left.fork(); // 异步执行左任务
        right.fork(); // 异步执行右任务

        return left.join() + right.join(); // 合并结果
    }
}

public class ParallelSumExample {
    public static void main(String[] args) {
        long[] data = new long[100_000];
        Arrays.fill(data, 1); // 填充测试数据
<pre class='brush:java;toolbar:false;'>    ForkJoinPool pool = new ForkJoinPool();
    SumTask task = new SumTask(data, 0, data.length);

    long result = pool.invoke(task);
    System.out.println("总和: " + result);

    pool.shutdown(); // 释放资源
}

try (ForkJoinPool pool = new ForkJoinPool()) {
    long result = pool.invoke(task);
    System.out.println("结果: " + result);
}