If you're new to OpenDaylight environment and try to follow the getting started guide at the official documentation page, you'll spend hours. In the worst case, it might take your entire weekend. :-) This short tutorial is a 'working' version of the official development getting started guide. Note that versions do matter. I've spent hours trying to get everything work for Nitrogen before I read this thread. It's still broken for Nitrogen. This guide is based on OpenDaylight Carbon.

OpenDaylight (ODL) is a modular open platform for customizing and automating networks of any size and scale. The OpenDaylight Project arose out of the SDN movement, with a clear focus on network programmability. It was designed from the outset as a foundation for commercial solutions that address a variety of use cases in existing network environments.