Here you have it, pictures showing China's J-20 stealth fighter's weapons bay doors open.
It's a big jet and these images appear to show its multiple weapons bays. You can see the smaller lateral bays squeezed into to the space forward of the main landing gear and the engine inlets. These side bays are apparently meant to carry short range air-to-air missiles (AAMs). Here's another great picture of them. In the image below, it looks like you can see the larger, center-line bay open (or just a landing gear door shown at a weird angle, but I don't think so). That space may be designed to carry larger AAMs such as this new missile.
Above images via China Defense Blog.
I posted the following images to give you a better sense of the space found between the landing gear and engine inlets and the overall layout of the belly of the jet. The last picture shows the diverterless engine inlets head-on. In addition to aiding engine performance and reducing radar signature, these 'bumps' in the intakes can also create space for weapons bays. Finally, we've published this picture before but it gives you a great sense of just how big the J-20 is.
Here's a Photoshopped image showing the weapons bays of an F-22 on the J-20 that someone is trying to pass off as real.