Is Java RegEx case-insensitive?

In Java, when doing a replaceAll to look for a regex pattern like:

replaceAll("\\?i\\b(\\w+)\\b(\\s+\\1)+\\b", "$1"); 

(to remove duplicate consecutive case-insensitive words, e.g. Test test), I'm not sure where I put the ?i. I read that it is supposed to be at the beginning, but if I take it out then i catch duplicate consecutive words (e.g. test test), but not case-insensitive words (e.g. Test test). So I thought I could add the ?i in the beginning but that does not seem to get the job done. Any thoughts? Thanks!

You can also match case insensitive regexs and make it more readable by using the Pattern.CASE_INSENSITIVE constant like:

Pattern mypattern = Pattern.compile(MYREGEX, Pattern.CASE_INSENSITIVE);
Matcher mymatcher= mypattern.matcher(mystring);

RegexBuddy is telling me if you want to include it at the beginning, this is the correct syntax:

"(?i)\\b(\\w+)\\b(\\s+\\1)+\\b"