JavaForkJoinPool使用教程详解

import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.RecursiveTask;
public class SumTask extends RecursiveTask {
private final long[] array;
private final int start;
private final int end;
private static final int THRESHOLD = 1000; // 任务拆分阈值
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 leftTask = new SumTask(array, start, mid);
        SumTask rightTask = new SumTask(array, mid, end);

        leftTask.fork(); // 异步执行左任务
        Long rightResult = rightTask.compute(); // 当前线程执行右任务
        Long leftResult = leftTask.join();      // 等待左任务结果

        return leftResult + rightResult;
    }
}

public static void main(String[] args) {
    long[] data = new long[10000];
    for (int i = 0; i < data.length; i++) {
        data[i] = i + 1;
    }

    ForkJoinPool pool = new ForkJoinPool();
    ForkJoinTask<Long> task = new SumTask(data, 0, data.length);
    Long result = pool.invoke(task); // 提交任务并等待结果
    System.out.println("Sum: " + result);

    pool.shutdown(); // 关闭线程池
}
}

ForkJoinPool commonPool = ForkJoinPool.commonPool();
Long result = commonPool.invoke(new SumTask(data, 0, data.length));