Sometimes users ask for TT4J to include a tokenizer. I will not include a ready-to-use tokenizer with TT4J, since there are other libraries that do a much better job here. A good tokenizer for English for example is included with the Stanford Parser.
If you do not wish to look for a good tokenizer for your task, you may find this method useful. It uses a simple tokenizer called !BreakIterator which ships with Java.