Java tutorial
import java.io.FileOutputStream; import java.io.IOException; import java.nio.channels.FileChannel; public class Main { public static void main(String[] args) throws IOException { byte b[] = { 65, 66, 67, 68, 69 }; FileOutputStream fos = new FileOutputStream("C://test.txt"); fos.write(b); // pushes stream content to the underlying file fos.flush(); // returns file channel associated with this stream FileChannel fc = fos.getChannel(); // returns the number of bytes written long pos = fc.position(); System.out.print(pos); } }