小编str*_*vil的帖子

我正在使用Java SE 7中的RecursiveTask测试Fibonacci示例http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/RecursiveTask.html.

该计划如下:

import java.util.concurrent.*;

public class testfuture{
    public static void main(String[] args) {
        System.out.println("Hello, World");
        Fibonacci fib = new Fibonacci(10);
        int result = fib.compute();
        System.out.println(result);
        }
}

class Fibonacci extends RecursiveTask<Integer> {
    final int n;
    Fibonacci(int n) { this.n = n; }
    public Integer compute() {
        if (n <= 1)
        return n;
        Fibonacci f1 = new Fibonacci(n - 1);
        f1.fork();
        Fibonacci f2 = new Fibonacci(n - 2);
        return f2.invoke() + f1.join();
    }
}

但是,该程序会抛出运行时异常

Hello, World …