How to sort file names in ascending order?

Question

I have a set of files in a folder, and all of them starting with a similar name, except one. Here is an example:

Coordinate.txt
Spectrum_1.txt
Spectrum_2.txt         


        

Answer 1

Arrays.sort(fileList, new Comparator()
{
    @Override
    public int compare(Object f1, Object f2) {
        String fileName1 = ((File) f1).getName();
        String fileName2 = ((File) f1).getName();

        int fileId1 = Integer.parseInt(fileName1.split("_")[1]);
        int fileId2 = Integer.parseInt(fileName2.split("_")[1]);

        return fileId1 - fileId2;
    }
});

make sure to handle files that does not has _ in the name