Java在JDK7之后加入了并行计算的框架Fork/Join，可以解决我们系统中大数据计算的性能问题。Fork/Join采用的是分治法，Fork是将一个大任务拆分成若干个子任务，子任务分别去计算，而Join是获取到子任务的计算结果，然后合并，这个是递归的过程。子任务被分配到不同的核上执行时，效率最高。

package com.thread.forkjoin;import java.util.Arrays;import java.util.Random;import java.util.concurrent.ExecutionException;import java.util.concurrent.ForkJoinPool;import java.util.concurrent.RecursiveTask;/** * Java在JDK7之后加入了并行计算的框架Fork/Join，可以解决我们系统中大数据计算的性能问题。 * Fork/Join采用的是分治法，Fork是将一个大任务拆分成若干个子任务，子任务分别去计算，而Join是获取到子任务的计算结果，然后合并，这个是递归的过程。 * 子任务被分配到不同的核上执行时，效率最高。 */public class ForkJoinTest extends RecursiveTask
    
      {    private static final int THREADSHOLD = 50000;    private long[] array;    private int low;    private int hight;    public ForkJoinTest(long[] array, int low, int hight) {        this.array = array;        this.low = low;        this.hight = hight;    }    @Override    protected Long compute() {        long sum = 0;        if (hight - low < THREADSHOLD) {            for (int i = low; i < hight; i++) {                sum += array[i];            }        } else {            int middle = (low + hight) >>> 1;            ForkJoinTest left = new ForkJoinTest(array, low, middle);            ForkJoinTest right = new ForkJoinTest(array, middle + 1, hight);            left.fork();            right.fork();            sum = left.join() + right.join();        }        return sum;    }    public static void main(String[] args) throws ExecutionException, InterruptedException {        long[] array = genArray(1000000);        System.out.println(Arrays.toString(array));        ForkJoinTest forkJoinTest = new ForkJoinTest(array, 0, array.length - 1);        long begin = System.currentTimeMillis();        ForkJoinPool forkJoinPool = new ForkJoinPool();        forkJoinPool.submit(forkJoinTest);        Long result = forkJoinTest.get();        long end = System.currentTimeMillis();        System.out.println(String.format("结果 %s 耗时 %sms", result, end - begin));    }    private static long[] genArray(int size) {        long[] array = new long[size];        for (int i = 0; i < size; i++) {            array[i] = new Random().nextLong();        }        return array;    }}