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:



Hence, 28 is a happy number.*/

import java.io.*;
class Happy
{
static BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
int n;
Happy()
{
n=0;
}
void getnum(int nn)
{
n=nn;
}
int sum_sq_digits(int x)
{
if(x==0)
return 0;
else
{
int d=x%10;
return (d*d+ sum_sq_digits(x/10));
}
}
void ishappy()
{
int a=sum_sq_digits(n);
while(a>9)
{
a=sum_sq_digits(a);
}
if(a==1)
System.out.print(n+" is a Happy Number");
else
System.out.print(n+" is Not a Happy Number");
}
public static void main()throws IOException
{
Happy ob=new Happy();
System.out.print("Enter any number: ");
int b=Integer.parseInt(br.readLine());
ob.getnum(b);
ob.ishappy();
}
}