Well, java can seamlessly use your systems wifi capabilities... so that server example still holds merrit.
Remember that the internet is nothing more than a socket layer with a software protocol (http - HyperText Transfer Protocol) on top, there is no reason why you can't make a (http) socket connection from java to your wifi shield.
I do hope you mean your camera is a wireless IP camera, since the arduino won't be able to feed a video stream over wifi (it can't even do it over a wire, the constraint is in the arduino's processing speed and memory limitations).