How to get audio decibel (dB) from mp3 file every second in Android?

How to get audio decibel (dB) from mp3 file every second in Android?

I want to create a music player application that can show decibel value
every second when music player played a song. And when I increase a volume
of my Android device, it makes decibel value get bigger. Otherwise,when I
decrease, that value get smaller. I'm really stuck where I must start for
creating it.
I've ever read from another articles, this related with FFT, buffering,
volume, etc.. But I don't know how to put that compenent in my source
code.
Is there any idea for its source code example ??? Please, help me !!! I'm
really...really.. so depressed to find out that way..
Sorry for my poor English.. Thanks alot for your helping, I appreaciate.. :)