get method for geting the value from servlet.

i read a Headfirst servlet where written get method used to geting the value it doesn't change anything on the server.but we can also update database from get method.please help

I have no idea what you're talking about.

Can you quote exactly what was written, and identify the source of the quote?

Also, it's not clear what your question is. "Please help"? Help with what? What don't you understand?

means difference between idempotent and non-idempotent.

Ritesh raushan wrote:means difference between idempotent and non-idempotent.

I'm sure you can look up those terms on the web.

If you have a specific question about how this applies in some servlet context, please make the effort to ask a clear, complete question.