Reliance on default encoding, what should I use and why?

Question

FindBugs reports a bug:

Reliance on default encoding Found a call to a method which will perform a byte to String (or String to byte) conversion, a

Answer 1

When you are using a PrintWriter,

File file = new File(file_path);
Writer w = new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.UTF_16.name());
PrintWriter pw = new PrintWriter(w);
pw.println(content_to_write);
pw.close();