Well, yes. But contrary to the tone of all the other comments, it is the Russians who we should be suspicious of.
The Chinese are able to buy considerable resources from Australia, Brazil, Africa, the Middle East and soon Canada. And maybe even the US. But still, with the Russians, it has been a trickle of gas and oil. And the irony of the fact that Russia is on China's North borders. And we can see how the Russians play hardball by the fact that they cut off gas supplies to Europe a few years ago.
Seeing how the Chinese are able to cooperate with the others in resources, but not the Russians, tells me something about the Russians and not the Chinese.
I suspect, somewhere between the terms of the original 200 Su-27's, and the actual delivery, it was the Russians who double crossed the Chinese.
In fact China reverse engineered carrier based version of Su-27 known as Su-33. There are videos available on youtube. I think it is pretty easy to build a land based fighter-bomber out of it.