How to sort Alphanumeric String

Question

I have a problem with sorting strings which include integers. If I use the below code I get sorting like: 1some, 2some, 20some, 21some, 3some, some

However I want it

Answer 1

If you know that pattern is always NUMALPHA or ALPHANUM and alpha always same:

if(str1.length() != str2.length()){
   return str1.length() - str2.length();
}

return str1.compareTo(str2);