How to escape text for regular expression in Java

Question

Does Java have a built-in way to escape arbitrary text so that it can be included in a regular expression? For example, if my users enter \"$5\", I\'d like to match that exa

Answer 1

Pattern.quote("blabla") works nicely.

The Pattern.quote() works nicely. It encloses the sentence with the characters "\Q" and "\E", and if it does escape "\Q" and "\E". However, if you need to do a real regular expression escaping(or custom escaping), you can use this code:

String someText = "Some/s/wText*/,**";
System.out.println(someText.replaceAll("[-\\[\\]{}()*+?.,\\\\\\\\^$|#\\\\s]", "\\\\$0"));

This method returns: Some/\s/wText*/\,**

Code for example and tests:

String someText = "Some\\E/s/wText*/,**";
System.out.println("Pattern.quote: "+ Pattern.quote(someText));
System.out.println("Full escape: "+someText.replaceAll("[-\\[\\]{}()*+?.,\\\\\\\\^$|#\\\\s]", "\\\\$0"));

Answer 2

Difference between Pattern.quote and Matcher.quoteReplacement was not clear to me before I saw following example

s.replaceFirst(Pattern.quote("text to replace"), 
               Matcher.quoteReplacement("replacement text"));