How to normalize all special characters but umlauts?

Question

I'd like to normalize any extended ascii characters, but exclude umlauts.

If I'd like to include umlauts, I would go for:

Normalizer.normalize(value, Normalizer.Form.NFKD)
    .replaceAll("\\p{InCombiningDiacriticalMarks}+", "");

But how can I exclude german umlauts?

As a result I would like to get:

source: üöäâÇæôøñÁ

desired result: üöäaCaeoonA or similar

Answer 1

From here I see 2 solutions, the first one is quite dirty the second is quite boring to implement I guess.

• Remove from the string you want to normalize the characters with umlauts, then after normalization put them back.

• Don't use the pre-buit pattern p{InCombiningDiacriticalMarks}. Instead build your own one excluding umlaut. Take a look at :

  • Regex: what is InCombiningDiacriticalMarks?
  • Unicode blocks
  • Combining Diacritical Marks and Combining Diacritical Marks for Symbols