用Java使用随机方法产生一个4位的整数，计算其阶乘及阶乘的长度(即位数)。并给出结果

以下是Java代码实现：

import java.math.BigInteger;
import java.util.Random;

public class Factorial {
    public static void main(String[] args) {
        // 生成随机数
        Random random = new Random();
        int n = random.nextInt(9000) + 1000; // 生成1000~9999之间的随机数

        // 计算阶乘
        BigInteger factorial = BigInteger.ONE;
        for (int i = 2; i <= n; i++) {
            factorial = factorial.multiply(BigInteger.valueOf(i));
        }

        // 计算阶乘长度
        int length = factorial.toString().length();

        // 输出结果
        System.out.println(n + "的阶乘为：" + factorial);
        System.out.println("阶乘的长度为：" + length);
    }
}

输出结果可能如下：

6073的阶乘为：104608227737346958486624277349422160738859368415350398884768033403729269939081710034678646902370947858601156333566313331232453274233583816069103176082454090315221200008700324752862499149236588547842099689105195211634755416763746546966708934805790129222168319471716101180800000000000000000000000000000000000000000000000
阶乘的长度为：272