Java sort String array of file names by their extension

Question

I have an array of filenames and need to sort that array by the extensions of the filename. Is there an easy way to do this?

Answer 1

You can implement a custom Comparator of Strings. Make it sort them by the substring after the last index of '.'. Then pass in the comparator and your array into

Arrays.sort(stringArray, yourComparator);

//  An implementation of the compare method
public int compare(String o1, String o2) {
    return o1.substring(o1.lastIndexOf('.')).compareTo(o2.substring(o2.lastIndexOf('.'));
}