Java: Extend SimpleDateFormat with new pattern letters

Question

Java's SimpleDateFormat is used to format a Date object to a string. The formatter supports various pattern letters, which denote textual representation of a Date field. For example, yy is two-letter year, yyyy is four-letter year, and E is day of week.

For example, A SimpleDateFormat initialized with yyyy.MM.dd G 'at' HH:mm:ss z will format a date to something like 2001.07.04 AD at 12:08:56 PDT.

I would like to add some pattern letters to SimpleDateFormat. For example, want C to denote Hebrew weekday (יום ראשון, יום שני, ...).

What's the right way to extend SimpleDateFormat with these new pattern letters? The only online example I could find seems somewhat complicated. I can live with formatting only, without parsing.

Answer 1

E can already be used to get the day of the week. If you want it in hebrew, then initialize the SimpleDateFormat instance with the hebrew locale.

Answer 2

From what I can tell SDF was not build to be extendable so each Calendar field formatting is hardcoded into one method : (. What I would do is I would create a wrapper object and detect special (handled by me chars) and format output by my own in mixed formats i would divide format into whats before and after my format char, and pass them to original SDF and then glue the results together.