Note to self when using java regex - always call Matcher.matches() so that text matching actually happens

The general pattern of usage is:

1. regexString = [REGEX]

2. final Pattern p = Pattern.compile(regexString);

3. final Matcher matcher = p.matcher(text_to_match);

4. matcher.matches() 

DO NOT FORGET to call Matcher.matches().

Otherwise you will get messages like:

java.lang.IllegalStateException: No match found
at java.util.regex.Matcher.group(Matcher.java:468)

and you'll be wondering why because you have confirmed that the regex itself is correct. (http://www.fileformat.info/tool/regex.htm and http://rubular.com/ are useful tools for doing this quickly)

REMEMBER: call .matches() so that our Matcher actually performs the matching!

Just wasted 10 minutes wondering what I was doing wrong.