SortByFileTypeThenByName

/**
@author : Aamir khan
@url : chapter09.blogspot.in

Sort Files by type and then by names and vice versa
**/
private static Comparator SortByFileTypeThenByName() {

        return Comparator.comparing((File f) -> {
            String probeContentType = null;
            try {
                probeContentType = Files.probeContentType(f.toPath());
                if (probeContentType == null) {
                    probeContentType = "probeContentTypeIsNull";
                }
            } catch (IOException e) {}
            return probeContentType;
        }).thenComparing(File::getName);
    }