i have done BCA and i m interested in java language.so which course i should do further?

You can go for Vendor certifications like SCJP, SCWCD, SCBCD , etc... There are various institutes all across India offering Java based vendor courses. You surely can opt for them, in order to make a career in Java. Now these courses are offered by Oracle and is named as Oracle certified Java Progra

You should go for short term courses from institutes like NIIT & Aptech. Best of luck.