HAPPY NUMBER

A happy number is a number in which the eventual sum of the square of the digits of the number is equal to 1.
Example :
28 = 2^2 + 8^2 = 4 + 64 = 68
68 = 6^2 + 8^2 = 36 + 64 = 100
100 = 1 ^2 + 0 ^2 + 0^2 = 1 + 0 + 0 = 1
Hence 28 is a happy number.
Example :
12 = 1^2 + 2^2 = 1 + 4 = 5 Hence 12 is not a happy number.
Design a class Happy to check if a given number is a happy number.

Input: n = 19
Output: True 19 is Happy Number,
1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1
As we reached to 1, 19 is a Happy Number.
Input: n = 20
Output: False

import java.util.*;
class Happy
{
    int n,num;
    Scanner sc=new Scanner(System.in);
    Happy()
    {
        n=0;
    }
    void getnum()
    {
        System.out.println("Enter the number ");
        n= sc.nextInt();
    }
    int sum_sq_digits(int x)
    {
       if(x/10==0)
       return x*x;
       else
       {
       return (int)Math.pow(x%10,2)+ sum_sq_digits(x/10);
    }
    }
    void ishappy()
    {
        while((num=sum_sq_digits(n))/10!=0)
        {
            n=num;
        }
        if ( num==1) 
        System.out.println("It is a happy number ");
        else
        System.out.println("Not a happy number");
    }
    public static void main(String args[])
    {
        Happy ob = new Happy();
        ob.getnum();
        ob.ishappy();
    }
}