FileOutputStream writer = new FileOutputStream("output.txt");
Scanner scanner = new Scanner(Test.class.getResourceAsStream("input.txt"));
String line;
while(scanner.hasNextLine()){
    line = scanner.nextLine();
    String[] split = line.split(" ");
    byte[] chars = new byte[split.length];
    for (int i = 0; i < split.length; i++)
        chars[i] = (byte) (int) Integer.valueOf(split[i]);
    writer.write(chars);
}