JavaCompiler.getStandardFileManager(...,Locale,...) always uses default locale and ignores the one that user specifies.


<JavacTool.java>
.
.
.
public JavacFileManager getStandardFileManager(
        DiagnosticListener<? super JavaFileObject> diagnosticListener,
        Locale locale,
        Charset charset) {
        Context context = new Context();
        if (diagnosticListener != null)
            context.put(DiagnosticListener.class, diagnosticListener);
        context.put(Log.outKey, new PrintWriter(System.err, true)); // FIXME
        return new JavacFileManager(context, true, charset);
}
...
.

</JavacTool.java>

In the above Standard implementaion, locale is ignored.