private String fillWithZero(String str, Integer length) {
StringBuilder stringBuilder = new StringBuilder(length);
stringBuilder.append(str);
if (str.length() > length) {
stringBuilder.deleteCharAt(length);
} else if (str.length() < length) {
int tempLength = length - str.length();
for (int i = 0; i < tempLength; i++) {
stringBuilder.insert(0, "0");
}
}
return stringBuilder.toString();
}
