More efficient way to make a Twitter status in a string of just words
(subject to further changes)

In your simple example, how are the hashtags and usernames actually derived from the tweet?

My suggestion is to tokenize the tweet by whitespaces first, then look at the individual words to determine if they must be stored ("Vote") or discarded ("#LittleMonsters"). 

    // Delete all RT (retweets flags)
    text = text.replaceAll("RT", "");


You do realize that this will turn text like "ART!" into just "A!" right? Tokenizing first should remedy this issue.

On a related note, Apache Incubator Storm's tutorials usually use tweets as an example to demonstrate the Big Data approach. I'm not suggesting that you need such a set-up in your context, but perhaps you can give those a quick read-through to pick up some tips.