Walrus CMS is an easy to use intuitive edit-in-place java based content management system. No admin dashboard at all - which makes Walrus rather unique. Walrus uses inline editing - just click and edit, like in your usual document editing software.
Walrus was built from scratch using Spring framework technology and a full stack of other Java frameworks - Hibernate, theTiles, Freemarker.
It's architecture is very lightweight and clear, so it's really easy to extend and integrate. Documentation is included within the demo bundle that is available from their website.
You can also test the online demo as well: http://walrus.lt