reethu singh wrote:but without using any software i need to do coding in java...
That statement is contradictory. Java is software, so you can't do it without using software of some kind.
Reflection, as reethu said, is one possibility; but the question you should probably be asking yourself is: "why do I need to do this?". If it's for a school exercise, then fine; if you simply want to crack someone else's code in order to plagiarize it, then it isn't.
I have never, in 12 years of using Java, needed to do what you want, and Reflection is fiddly, error-prone, arcane and SLOW; so I'd think long and hard before you go down that road.
Isn't it funny how there's always time and money enough to do it WRONG?