I had to bust out my haynes manual to seeif i was right.
Since all gen 4's have speed sensors on all 4 corners and the same ABS hose adapters/fitments (things are different on the no abs models), i will say that you do have abs front and back...which kind of only makes sense. If you only had abs in the front and the rears locked up you'd be fish tailing your heart out...if not a total rotational spin.

Now i dont know if your camry has 4 way abs or just 3 way, but since there is no connected axle in the rear i will say you have 4 way independent abs just like on the 4 weel disc models. It'd be too costly for toyota to manufacture 3 different parts/designs for just the camry anyways.

in case you're wondering what is the differnce between 3 or 4 way abs.
My minivan had a 3 way abs system. it works like this.
Instead of 4 speed sensors there are only 3. 2 for the front two wheels and 1 for both the rear two. if at any one time one of the wheels in the rear would lock up the brakes would be pumped for both of the drums.
and the fronts always work independently to maximize brake force.

 

now thats some knowledge for my *** rite there.. thanks!