I was Joking,may be it can be fitted with few tweaks in airframe.But people must undertand that,it won't work because, neither JFT airframe can handle stress due to it's wight and thrust,neither it can provide it enough fuel.If anyhow they are able to strengthen that airframe for handling weight and stress of AL-31 117s,still it would be useless because it won't be able to sustain any combat mission due to limited fuel,it must be noted that current JFT carries 2330 kg of fuel while SU-27/30/35, if i am not wrong they have internal fuel capacity of around 10000-12000kg depending upon model.
If we take a JFT airframe and fit that Engine into it,it's extra length would take almost 2.34 Feet of extra length thus reducing quite good amount of fuel.In nutshell without going back on boards,and redesigning whole airframe it's impossible.