java, StandardCharsets utf-16 issue

September 29, 2023

I’m trying to undetstand why the results are different while I’m trying to write a test string using different encoding.
For StandardCharsets.UTF_16LE the result is "test" (seems correct), while
for StandardCharsets.UTF_16BE the resul is " t e s t" (seems wrong).
Can someone please explane why in the case of UTF_16BE the result is having unnecessary spaces between letters?

    String filename="C:\\Users\\name\\Downloads\\debugging.txt";
    String str="test";

    File fl = new File(filename);

    try (FileOutputStream fos = new FileOutputStream(fl);

         //BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos, StandardCharsets.UTF_16LE))) {//seems does work
         BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos, StandardCharsets.UTF_16BE))) {//seems does not work

        bw.write(str);
    } catch (IOException ignored) {
        //some actions
    }

>Solution :

Javadoc says:

When decoding, the UTF-16BE and UTF-16LE charsets interpret the
initial byte-order marks as a ZERO-WIDTH NON-BREAKING SPACE; when
encoding, they do not write byte-order marks.

Without a BOM, editors have to guess the correct encoding and they could be not so clever. Some editor could simply not support some encoding. So it depends on the editor that you use to read the file.