This is an Java API wrapping the http request commands to a wifi GoPro. It includes the project setting for eclispe. It was published on http://goprojavaapi.blogspot.ch/ and the source code on https://code.google.com/p/goprojavaapi under the Apache License 2.0.
It's wasn't complet though. I tried to contact the person behind it, but never got an answer. On some parts had bugs or seem unfinished I fixed it here and there and that's why I'm putting it on GitHub, it's a improved version. But honstely I didn't have the time to go through all the possible requests and test them. You're welcome to collaborate.
I used this API to extract single images out of a small videos recorded with gopro. See: https://github.com/DomDomHaas/gopro-image-extraction
(For commands see GoPro URL.txt)