Java计算器输出

Question

我正在尝试使用类和通过它们传递值来计算器。

我发现的问题是，当我编译时，程序没有给我任何答案。

这是我的代码：

package apps;

import java.util.Scanner;


public class Apps
{


public static void main(String[] args) throws Exception
{
   System.out.println("1.Add");
   System.out.println("2.Subtract");
   System.out.println("3.Divide");
   System.out.println("4.Multiply");

   String Input;
   String Input1;
   String Input2;

   int N1;
   int N2;



   Scanner UserIn = new Scanner(System.in);
   Input = UserIn.nextLine();
   char aChar = Input.charAt(0);

   System.out.println("Enter First number");
   Input1 = UserIn.nextLine();
   N1 = Integer.parseInt(Input1);

   System.out.println("Enter Second number");
   Input2 = UserIn.nextLine();
   N2 = Integer.parseInt(Input2);

   Calculator Calc = new Calculator();


   if (aChar == 1){
   System.out.println(Calc.Addition(N1,N2));
   } else if (aChar == 2){
   System.out.println(Calc.Subtraction(N1,N2));
   }else if (aChar == 3){
   System.out.println(Calc.Division(N1,N2));
   }

}

}



package apps;


public class Calculator
{
    public int Addition(int N1, int N2)
    {
        //num 1 + num2
       int totalA = N1 + N2;
       return totalA;

    }

public int Subtraction(int N1, int N2)
{
 //num 2 - num1 
   int totalS = N1 - N2;
   return totalS;

}

public int Division(int N1, int N2)
{
    int totalD = N2 / N1;
    return totalD;

}

}

谢谢你的帮助。