Ignoring diacritic characters when comparing words with special characters (é, è, ...)

Question

I have a list with some Belgian cities with diacritic characters: (Liège, Quiévrain, Franière, etc.) and I would like to transform these special characters to compare with a list containing the same names in upper case, but without the diacritical marks (LIEGE, QUIEVRAIN, FRANIERE)

What i first tried to do was to use the upper case:

LIEGE.contentEqual(Liège.toUpperCase()) but that doesn't fit because the Upper case of Liège is LIÈGE and not LIEGE.

I have some complicated ideas like replacing each character, but that sounds stupid and a long process.

Any ideas on how to do this in a smart way?

Answer 1

As of Java 6, you can use java.text.Normalizer:

public String unaccent(String s) {
    String normalized = Normalizer.normalize(s, Normalizer.Form.NFD);
    return normalized.replaceAll("[^\\p{ASCII}]", "");
}

Note that in Java 5 there is also a sun.text.Normalizer, but its use is strongly discouraged since it's part of Sun's proprietary API and has been removed in Java 6.