Converting String which contains Turkish characters to lowercase

Question

I want to convert a string which contains Turkish characters to lowercase with Turkish characters mapped into English equivalents i.e. "İĞŞÇ" -> "igsc".

When I use toLowerCase(new Locale("en", "US")) function it converts for example İ to i but with dotted.

How can I solve this problem? (I'm using Java 7)

Thank you.

Solution 1

You may

1) First, remove the accents :

the following comes from this topic :

Is there a way to get rid of accents and convert a whole string to regular letters? :

Use java.text.Normalizer to handle this for you.

string = Normalizer.normalize(string, Normalizer.Form.NFD);

This will separate all of the accent marks from the characters. Then, you just need to compare each character against being a letter and throw out the ones that aren't.

string = string.replaceAll("[^\\p{ASCII}]", "");

If your text is in unicode, you should use this instead:

string = string.replaceAll("\\p{M}", "");

For unicode, \P{M} matches the base glyph and \p{M} (lowercase) matches each accent.

2) Then, just put the remaining String to lower case

string = string.toLowerCase();

Solution 2

String testString = "İĞŞÇ";
System.out.println(testString);
Locale trlocale = new Locale("tr-TR");
testString = testString .toLowerCase(trlocale);
System.out.println(testString);

Works like a charm :)

Comments

[Alain BECKER]

The least I can say is that your solution is... not universal. When I try it, I get "iğşç", while the OP asked for "igsc"...