Question

I have a regular expression which will parse the content of a message and convert plain text hyperlinks into HTML hyperlinks.

message = message.replaceAll("(?:https?|http?)://[\\w/%.\\-?&=!#]+",
                             "<a href='$0' target='_blank'>$0</a>");

It is fine when converting http or https hyperlinks.

The problem is that I also have other hyperlinks enclosed within bbcode tags which I do not want the regular expression to converted into HTML hyperlinks.

E.g. [IMG]http://www.google.com/img.png[/IMG] or [YOUTUBE]http://www.youtube.com[/YOUTUBE]

How do I change my regular expression to prevent the regex from converting bbcode hyperlinks?

Answer 1

You can use negative lookbehind.

"(?<!\])(?:https?|http?)://[\\w/%.\\-?&=!#]+"

The (?<!\]) will only allow the rest of the URL pattern to match if it does not immediately follow a ']'.