Number of 1 Bits

/* Programmer     : Dhruv Patel
*  Problem Name   : Number of 1 Bits
*  Used In        : Leetcode
*  Used As        : 191
*  Problem        :
*                    Write a function that takes an unsigned integer and returns the number of '1' bits it has 
*                    (also known as the Hamming weight).
*                    For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, 
*                    so the function should return 3.
*  Credits:
*                    Special thanks to @ts for adding this problem and creating all test cases.
*  Thoughts       => 
*                    Brute Force / Naive Approach :- We convert int number to the BigDecimal with 32-bit string and shooting a loop
*                                                    to count ASCII - '49' which returns the number of ones.
*
*/
import java.math.BigDecimal;

class Solution {
    public static int hammingWeight(int n) {
        BigDecimal b = new BigDecimal(n + "");
        StringBuilder b1 = new StringBuilder(String.format("%32s", Integer.toBinaryString(b.intValue()))
                .replace(' ', '0'));
        int count = 0;
        for (char k : b1.toString().toCharArray()) {
            if (k == 49) {
                count++;
            }
        }
        return count;
    }

    public static void main(String args[]) {
        for (int i = 0; i < Integer.MAX_VALUE; i++) {
            System.out.println("Total number of zeroes in number " + i + " " + hammingWeight(i));
        }
    }
}