Since I use Sublime ,I want to write a encoding convent program .

Here is the knowage what i need .

InputStreamReader:

This class is the brage from byte type to reffered charset . 

FileInputStream :

This class read file to byte .

I think that file has no Charset ,File just store data I just should wirte data by refferd charset is ok.

When read file ,just load  it by refferd  charset .