Question

I have a list of String characters, They are mix characters that includes special characters too. I want to know how to sort them ascendingly ?

updated
example
aplha1.jpg
aplha10.jpg
2.jpg
3.jpg
4.jpg
aplha5.jpg

Answer 1

I hope this will work for you.

public class AlphanumericSorting implements Comparator<String> {

    public int compare(String firstObjToCompare, String secondObjToCompare) {
        String firstString = firstObjToCompare.toString();
        String secondString = secondObjToCompare.toString();

        if (secondString == null || firstString == null) {
            return 0;
        }

        int lengthFirstStr = firstString.length();
        int lengthSecondStr = secondString.length();

        int index1 = 0;
        int index2 = 0;

        while (index1 < lengthFirstStr && index2 < lengthSecondStr) {
            char ch1 = firstString.charAt(index1);
            char ch2 = secondString.charAt(index2);

            char[] space1 = new char[lengthFirstStr];
            char[] space2 = new char[lengthSecondStr];

            int loc1 = 0;
            int loc2 = 0;

            do {
                space1[loc1++] = ch1;
                index1++;

                if (index1 < lengthFirstStr) {
                    ch1 = firstString.charAt(index1);
                } else {
                    break;
                }
            } while (Character.isDigit(ch1) == Character.isDigit(space1[0]));

            do {
                space2[loc2++] = ch2;
                index2++;

                if (index2 < lengthSecondStr) {
                    ch2 = secondString.charAt(index2);
                } else {
                    break;
                }
            } while (Character.isDigit(ch2) == Character.isDigit(space2[0]));

            String str1 = new String(space1);
            String str2 = new String(space2);

            int result;

            if (Character.isDigit(space1[0]) && Character.isDigit(space2[0])) {
                Integer firstNumberToCompare = new Integer(Integer.parseInt(str1.trim()));
                Integer secondNumberToCompare = new Integer(Integer.parseInt(str2.trim()));
                result = firstNumberToCompare.compareTo(secondNumberToCompare);
            } else {
                result = str1.compareTo(str2);
            }

            if (result != 0) {
                return result;
            }
        }
        return lengthFirstStr - lengthSecondStr;
    }

}