How to remove all non-alphanumeric characters from a string expect decimal point in Java

Having this String with decimal point, I would like to remove all non alphaNumeric expect the decimal point.

 String toPharse = "the. book - cost 7.55 dollars.";

 String newPharse =  toPharse.replaceAll("[^A-Za-zd.0-9 ]", " ").replaceAll("\s+", " ");

Currently I get "the. book cost 7.55 dollars.";

However I would like to return "the book cost 7.55 dollars";

Answer

You can use:

String toPharse = "the. book - cost 7.55 dollars.";
toPhrase = toPharse
   .replaceAll("(?<!\d)\.(?!\d)|[^a-zA-Z\d. ]+", "")
   .replaceAll("\h{2,}", " ");

//=> "the book cost 7.55 dollars"

RegEx Demo

RegEx Details:

• (?<!\d): Previous character is not a digit
• \.: Match a dot
• (?!\d): Next character is not a digit
• |: OR
• [^a-zA-Z\d. ]+: Match 1+ of non-alphanumeric characters that are not space or dot
• .replaceAll("\h{2,}", " "): is for replacing 2+ whitespaces with a single space