JUC_分支合并框架

一、分支合并框架

1.原理

2.相关类

ForkJoinPool

3.计算0，100的总和=5050

//计算0，100的总和=5050
class MyTask extends RecursiveTask<Integer>{

    //声明一些变量
    //以10为界限区分！
    private static final Integer ADJUST_VALUE = 10;
    private int begin;
    private int end;
    private int result;

    //创建一个构造方法
    public MyTask(int begin,int end){
        this.begin = begin;
        this.end = end;
    }

    //递归调用
    @Override
    protected Integer compute() {
        if ((end-begin)<=ADJUST_VALUE){
            for (int i = begin; i <=end; i++) {
                result = result+i;
            }
        }else {
            //0,100 相差100 找个中间值 100/2=50 0,50  51,100
            int mid = (begin+end)/2;
            MyTask myTask01 = new MyTask(begin, mid);
            MyTask myTask02 = new MyTask(mid+1, end);
            //计算
            myTask01.fork();
            myTask02.fork();

            //最终计算结果
            result = myTask01.join()+myTask02.join();
        }
        return result;
    }
}


public class ForkJoinDemo {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        MyTask myTask = new MyTask(0, 100);
        //分支合并池
        ForkJoinPool forkJoinPool = new ForkJoinPool();
        //需要将ForkJoinTask扔进去
        ForkJoinTask<Integer> forkJoinTask = forkJoinPool.submit(myTask);
        System.out.println(forkJoinTask.get());
    }
}