Radix sort in java

Grouping of the items with their MSB and then compare and merge. The number of digits in each element should be made same. In the below example it is 2 ie, 3 = 03 or 8 = 08.

import java.util.ArrayList;

public class RadixSort {

	public void radixSort(int arr[], int maxDigits){
		int exp = 1;//10^0;
		for(int i =0; i < maxDigits; i++){
			ArrayList bucketList[] = new ArrayList[10];
			for(int k=0; k < 10; k++){
				bucketList[k] = new ArrayList();
			}
			for(int j =0; j < arr.length; j++){
				int number = (arr[j]/exp)%10;
				bucketList[number].add(arr[j]);
			}
			exp *= 10;
			int index =0;
			for(int k=0; k < 10; k++){
				for(int num: bucketList[k]){
					arr[index] = num;
					index++;
				}
			}
		}

		System.out.println("Sorted numbers");
		for(int i =0; i < arr.length; i++){
			System.out.print(arr[i] +", ");
		}
	}

	public static void main(String[] argv){
		int n = 5;
		int arr[] = {1,4,2,3,5,10,8};
		new RadixSort().radixSort(arr, 2);
	}
}