java 实例 设计一个方法，计算一个数的n次幂

例如，首先输入  2 4就是计算2的4次方，如果出现负数，则抛出异常

代码如下：

import java.util.*;
import java.util.Scanner;
class MyCalculator {
    long power(int n, int p) throws Exception {
        if (n < 0 || p < 0) {
            throw new Exception("n and p should be non-negative");
        } else {
            return (long) Math.pow(n, p);
        }
    }
}
class Solution {

 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);

  while ( in .hasNextInt()) {
   int n = in .nextInt();
   int p = in .nextInt();
   MyCalculator my_calculator = new MyCalculator();
   try {
    System.out.println(my_calculator.power(n, p));
   } catch (Exception e) {
    System.out.println(e);
   }
  }
 }
}