在Java中使用多个类创建程序时遇到问题

我正在尝试创建一个程序，其中用户输入四位数字，并给出一个六位数字。前四位是用户输入的数字，第五位是（（digit1+digit2+digit4）%10），第六位是第三位。这是我到目前为止所拥有的。已提供用于用户输入的类。感谢您的帮助

import java.lang.Math;

/**
* Purpose: This class/program generates a 6 digit card number based on 4 digits inputed by the user
*/
public class CardGenerator
{
   public void main(String[] args)
   {    
      UserInteraction input = new UserInteraction();
      calculateDigit5 digit5Calc = new calculateDigit5();
      getDigit digit = new getDigit();
      getRemainder remainder = new getRemainder();

      int number = input.getIntValueFromUser("Enter the four digit card number"),
          digit1 = getDigit(number, 3),
          number = getRemainder(number, 3),
          digit2 = getDigit(number, 2),
          number = getRemainder(number, 2),
          digit3 = getDigit(number, 1),
          number = getRemainder(number, 1),
          digit4 = getDigit(number, 0),
          digit5 = calculateDigit5,
          digit6 = digit3;

      System.out.println("The 6 digit card number is " + digit1 + digit2 + digit3 + digit4 + digit5
      + digit6);
   }

   public class getDigit
   {
     int digitWeight = Math.pow(number, (1/1000)),
                 rem = getRemainder(number, digitPosition),
               digit = (originalNumber - rem) / digitWeight;


   }

   public class getRamainder
   {

   }

   public class calculateDigit5
   {
     int digit5 = (digit1 + digit2 + digit4) % 10;
   }
}

这是提供给我的

import java.util.*;
//DO NOT PUT OTHER METHODS IN THIS CLASS or make any changes to it
public class UserInteraction
{
    public String getStringValueFromUser(String message)
    {
        String value = "";
        Scanner input = new Scanner(System.in);
        System.out.print(message + " : ");
        value = input.nextLine();
        return value;
    }
//DO NOT PUT OTHER METHODS IN THIS CLASS or make any changes to it
    public double getDoubleValueFromUser(String message)
    {
        double value = 0;
        Scanner input = new Scanner(System.in);
        System.out.print(message + " : ");
        value = input.nextDouble();
        return value;
    }
//DO NOT PUT OTHER METHODS IN THIS CLASS or make any changes to it
    public int getIntValueFromUser(String message)
    {
        int value = 0;
        Scanner input = new Scanner(System.in);
        System.out.print(message + " : ");
        value = input.nextInt();
        return value;
    }

  //DO NOT PUT OTHER METHODS IN THIS CLASS or make any changes to it
}

公共类所有数字{
私有int[]位；
公共所有数字（）
{
数字=新整数[6]；
}
公共整数getDigit（整数索引）
{
返回数字[索引]；
}
公共void setDigit（int索引，int值）
{
如果（索引>=0&&index
public class AllDigits {

private int[] digits;

public AllDigits()
{
    digits = new int[6];
}

public int getDigit(int index)
{
    return digits[index];
}

public void setDigit(int index, int value)
{
    if(index >= 0 && index <=3)
    {
        digits[index] = value;
        //if we are setting the 3rd number set the 6th as well
        if(index == 2)
            digits[5] = value;
    }
    //this is for the fifth digit
    else if(index == 4)
    {
        digits[index] = (digits[0] + digits[1] + digits[3]) % 10;
    }
}

public void printDigit()
{
    for(int i = 0; i < digits.length; i++)
    {
        System.out.print(digits[i]);
        if(i != digits.length - 1)
            System.out.print(" ");
    }
    System.out.println();
}
}