import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Iterator;
import java.util.stream.Stream;


public class StringToBytes {


 private static void convertor(Stream<String> input) throws IOException
 {

     File file = new File("byteTest.txt");
        BufferedOutputStream writer = new BufferedOutputStream(new FileOutputStream(file));

    Iterator<String> it= input.iterator();

    while (it.hasNext())
    {
        byte []b= it.next().getBytes();
        writer.write(b);

    }
    writer.close();
}

public static void main(String args[]) throws IOException{
    Path path= Paths.get("test.txt");

    Stream<String>lines=Files.lines(path, StandardCharsets.UTF_8);
    convertor(lines);
}
}