how can i get certificate in java. can anybody tell me any certified on-line exam .?

Question

i have learnt it and i dont want to join any institute to learn again.

Answer 1

This is the link for the index you are looking for.
I don't know what sort of certification you want so start here.
Follow the links and find out what is best for you.

I think you will find that you have to pay and that you have to go to an approved venue to take the test. It cannot be done online.