Java regex replaceAll multiline

Question

I have a problem with the replaceAll for a multiline string:

String regex = "\\s*/\\*.*\\*/"; String testWorks = " /** this should be replaced **/ just text"; String testIllegal = " /** this should be replaced \n **/ just text";  testWorks.replaceAll(regex, "x");  testIllegal.replaceAll(regex, "x");  

The above works for testWorks, but not for testIllegal!? Why is that and how can I overcome this? I need to replace something like a comment /* ... */ that spans multiple lines.

Answer 1

You need to use the Pattern.DOTALL flag to say that the dot should match newlines. e.g.

Pattern.compile(regex, Pattern.DOTALL).matcher(testIllegal).replaceAll("x") 

or alternatively specify the flag in the pattern using (?s) e.g.

String regex = "(?s)\\s*/\\*.*\\*/";