why wrote:
Write your own simple String arrayToString(int[]) and int[] stringToArray(String) helper methods (assume you have an int array to store), e.g.

StringBuffer sb = new StringBuffer();
String delimiter = "#";
for (int i = 1; i < intArray.length; i++) {
sb.append(int).append(delimiter);
}
retrun sb.toString();

string[] strArray= str.split(delimiter);
int[] intArray = new int[strArray.length];
for (int i = 1; i < strArray.length; i++) {
intArray[i] = Integer.parseInt(strArray[i]);
}
return intArray;