How to split abccbaabc in java



Hi Everyone,
I want to do a map reduce code. I want to split a codon string ababcadcabcabc like using java.

I want to do make a word using 3 characters like aba, then bca , then dca. But for split, i donot have a delimiter ilke comma, colon, I have to use 3 charcaters and make a word, similarly the next word using next 3 characters.

Can you please guide me how to implement it.