ForkJoin框架示例（一）

package com.zzj.concurrency;import java.io.IOException;import java.util.Random;import java.util.concurrent.ForkJoinPool;import java.util.concurrent.RecursiveAction;/** * 计算一千万个1到100之间的数值之和，此示例使用没有返回值的任务，没有合并结果 * @author lenovo * */public class ForkJoinTest {    static int[] nums = new int[10000000];    static int max_num = 50000;    static{        Random r = new Random();        for (int i = 0; i < nums.length; i++) {            nums[i] = r.nextInt(100);        }    }    /**     * 没有返回值     * @author lenovo     *     */    static class AddTask extends RecursiveAction{        private static final long serialVersionUID = 1L;        private int start;        private int end;        public AddTask(int start, int end) {            this.start = start;            this.end = end;        }        @Override        protected void compute() {            if (end - start <= max_num) {                int s = 0;                for (int i = start; i < end; i++) {                    s += nums[i];                }                System.out.println("from " + start + " to " + end + ":" + s);            } else {                int middle = start + (end - start) / 2;                AddTask addTask1 = new AddTask(start, middle);                AddTask addTask2 = new AddTask(middle, end);                addTask1.fork();                addTask2.fork();            }        }    }    public static void main(String[] args) throws IOException {        ForkJoinPool pool = new ForkJoinPool();        pool.execute(new AddTask(0, nums.length));        System.in.read(); // 必须阻塞，ForkJoinPool线程是后台线程    }}