Java tutorial
import java.io.BufferedOutputStream; import java.io.FileOutputStream; public class Main { public static void main(String[] args) throws Exception { FileOutputStream fos = new FileOutputStream("C:/Demo.txt"); BufferedOutputStream bos = new BufferedOutputStream(fos); byte b = 66; // write a character represented by ascii 66 i.e. 'B' bos.write(b); bos.flush(); bos.close(); } }