While reviewing the API signature changes for 8u40 I noticed that the following protected fields of DateTimeStringConverter do not have proper javadoc comments. Note that protected fields and methods in Java are public API (meaning that the comment preceding those fields is simply wrong).
protected final Locale locale;
protected final String pattern;
protected final DateFormat dateFormat;
protected final int dateStyle;
protected final int timeStyle;
I expect that these were not intended to be public API, but since they are, we need to document them at some point.