How to find the most frequent digit in a number string?

import java.util.ArrayList;
import java.util.List;

public class MostFrequentDigits1 {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

long number = 12345612;
String str = "12342352397235823050237238523";
getMostFrequentDigitWInNumber(number);
getMostFrequentDigitInString(str);

}

public static void getMostFrequentDigitWInNumber(long number) {
List list = new ArrayList();
int[] frequency = new int[10];
int mostFrequentVal = 0;
while (number > 0) {
int digit = (int) (number % 10);
number /= 10;
frequency[digit]++;
if (frequency[digit] > mostFrequentVal) {
mostFrequentVal = frequency[digit];
}
}

for (int j = 0; j < frequency.length; j++) {
if (frequency[j] == mostFrequentVal) {
list.add(j);
}
}
System.out.println("most frequent digits in Number:" + list);
}

public static void getMostFrequentDigitInString(String str) {
List list = new ArrayList();
int mostFrequentVal = 0;
int[] frequency = new int[10];
for (int k = 0; k < str.length(); k++) {
char c = str.charAt(k);
int ind = Integer.valueOf(String.valueOf(c));
frequency[ind]++;
if (frequency[ind] > mostFrequentVal) {
mostFrequentVal = frequency[ind];
}
}

for (int j = 0; j < frequency.length; j++) {
if (frequency[j] == mostFrequentVal) {

list.add(j);
}
}
System.out.println("most frequent digits in string:" + list);
}

}