【java多线程】分段阶乘计算

阶乘线程类：Factorial.java
需要返回值，故实现Callable接口，call()返回计算结果

import java.util.concurrent.Callable;

public class Factorial implements Callable<Object>{

    private long val1;
    private long val2;
    private long sum;
    private long time;
    public Factorial(long val1, long val2) {
        this.val1 = val1;
        this.val2 = val2;
    }

    public  void  sum() throws InterruptedException {
        long temp =val1;
        for (long i = 1; i < val2 - val1 + 1; i++) {
            temp *= (val1+i);
        }
        sum = temp;
    }

    @Override
    public Object call() throws Exception {

        System.out.println("线程 "+ Thread.currentThread().getName() + ":运行，计算"+val1+"~"+val2+"的阶乘");
        long t1 = System.currentTimeMillis();
        sum();
        long t2 = System.currentTimeMillis();
        time = t2 - t1;
        System.out.println("线程 "+ Thread.currentThread().getName() + ":结束，执行时间"+time+"ms");
        return sum;
    }

    public long getTime() {
        return time;
    }

    public void setTime(long time) {
        this.time = time;
    }

}

Main.java:

public class Main {

    public static void main(String[] args) throws InterruptedException, ExecutionException {

            Factorial c = new Factorial(1,10);
            FutureTask<Object> result = new FutureTask<Object>(c);
            new Thread(result).start();

            Factorial c2 = new Factorial(11,20);
            FutureTask<Object> result2 = new FutureTask<Object>(c2);
            new Thread(result2).start();

            long a = (long) result.get();
            long b = (long) result2.get();

            System.out.println("sum : "+(a*b));
    }

}