It will be blockaded itself, as the US can within 48hrs blockade all commercial traffic in and out of china. China doesn't have much oil by itself, and it needs imports to properly feed its population.
It will end up like those scenarios, where the sieging forces, get sieged and cut off itself. Its navy is a near-shore force, and just can't project force outside the China sea. They can completely control the part of China sea near about 200-400km near its shore, but it will be unable to go any further than that.
It might end up like a Japan, 1941 scenario. They might be able to score some early surprise wins, but on the long term they are doomed to lose the war.
Ps. While china is experiencing a boom like the 50s and 60s in the USA (lots of infrastructure being built), China's demographic is aging, and we might see a scenario that the current boom will just slow down, and itself end up in a situation like Japan in the 90s, or USA itself in the 70s. It will reach a peak in the next 10 years (economically) and start leveling off to more normal rates of growth.