[开发工具]JAVA利用 executor 并发框架，实现 计算100的阶乘分解为 10 个子任务运算（idea）源码

我们知道100的阶乘的值为：

100的阶乘为：93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000

这个值很大，一般数据类型无法接受，只有用JAVA程序语言中的 BigInteger 来接收

采用并发框架 executor 来计算

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程序源代码

package text.ght02;

//编写一个测试程序，利用 executor 并发框架，实现 100!分解为 10 个子任务运算。

public class Main {

    public static void main(String[] args) throws InterruptedException {
        // 创建一个执行服务器
        Server server=new Server();

        // 创建10个任务，并发给执行器，等待完成
        for (int i=0; i<10; i++){
            Task task=new Task("Task "+i);
            Thread.sleep(10);
            server.submitTask(task);
        }
        server.endServer();
    }
}

package text.ght02;
import text.ght02.Task;

import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;

/**
 * 执行服务器
 *
 */
public class Server {

    //线程池
    private ThreadPoolExecutor executor;

    public Server(){
        executor=(ThreadPoolExecutor)Executors.newCachedThreadPool();
        //executor=(ThreadPoolExecutor)Executors.newFixedThreadPool(5);
    }

    //向线程池提交任务
    public void submitTask(Task task){
        System.out.printf("Server: A new task has arrived\n");
        executor.execute(task); //执行  无返回值

        System.out.printf("Server: Pool Size: %d\n",executor.getPoolSize());
        System.out.printf("Server: Active Count: %d\n",executor.getActiveCount());
        System.out.printf("Server: Completed Tasks: %d\n",executor.getCompletedTaskCount());
    }

    public void endServer() {
        executor.shutdown();
    }
}

package text.ght02;

import javax.management.StringValueExp;
import java.math.BigInteger;
import java.util.Date;
import java.util.concurrent.TimeUnit;

/**
 * Task 任务类
 */
public class Task implements Runnable {

    private String name;
    public volatile BigInteger result = new BigInteger("1");//结果
    
    public volatile int time = 1;//用于计算100的阶乘，当做工具数

    public Task(String name) {
        this.name = name;
    }

    public void run() {
        while (true)// 循环是指线程不停的去执行业务操作
        {
            String str = Thread.currentThread().getName();

            BigInteger num = new BigInteger(String.valueOf(time));
            result = result.multiply(num);
            time++;
            System.out.println(str + "得到的值为：" + result);
            System.out.printf("%s: Task %s: Finished on: %s\n", Thread.currentThread().getName(), name, new Date());

//            for (int i = k; i < k + 10; i++) {
//                BigInteger num = new BigInteger(String.valueOf(i));
//                result = result.multiply(num);
//                System.out.printf("%s: Task %s: Finished on: %s\n", Thread.currentThread().getName(), name, new Date());
//            }

            if (time > 100) {
                System.out.println("最终结果为：" + result);
                break;
            }
        }

    }
}

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