Localized date format in Java

问题:

I have a timestamp in millis and want to format it indicating day, month, year and the hour with minutes precission.

I know I can specify the format like this:

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("MM/dd/yy HH:mm");
String formatted = simpleDateFormat.format(900000)

But I'd like the format to be localized with the user's locale. I've also tried

DateFormat DATE_FORMAT = DateFormat.getDateInstance(DateFormat.SHORT, Locale.getDefault());
DATE_FORMAT.format(new Date());

But it does not show the hour. How can I do it?

回答1:

Is using joda time (http://joda-time.sourceforge.net/) out of the question? If not, then I would wholeheartedly recommend using this wonderful library instead of the cumbersome Java API.

If not, you could use DateFormat.getDateTimeInstance(int, int, Locale)

The first int is the style for hour, the other is the style for time, so try using:

DateFormat f = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, Locale.getDefault());
String formattedDate = f.format(new Date());
System.out.println("Date: " + formattedDate);

See if this suits you.

Output for Locale.GERMANY: Date: 25.07.13 10:57

Output for Locale.US: Date: 7/25/13 10:57 AM

回答2:

But it does not show the hour. How can I do it?

You have to call DateFormat.getDateTimeInstance(int, int, Locale)

DateFormat.getDateInstance(int, Locale) => Gets the date formatter with the given formatting style for the given locale.

While

DateFormat.getDateTimeInstance(int, int, Locale) => Gets the date/time formatter with the given formatting styles for the given locale.

回答3:

Try some thing like this

    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("MM/dd/yy HH:mm", Locale.getDefault());
    String formatted = simpleDateFormat.format(900000);
    System.out.println(simpleDateFormat.parse(formatted));

回答4:

You can use method getDateTimeInstance, of DateFormat. Here the getDateTimeInstance method takes 3 arguments

1. the style of Date field
2. the style of time field

3. the Locale using which pattern is auto extracted

   DATE_FORMAT = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, Locale.US);
   System.out.println(DATE_FORMAT.format(d));
   DATE_FORMAT = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM, Locale.FRENCH);
   System.out.println(DATE_FORMAT.format(d));
   

回答5:

You can use something like this:

SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yy HH:mm", Locale.getDefault());
String formatted = sdf .format(900000);
System.out.println(simpleDateFormat.parse(formatted));

回答6:

Using Joda-Time you could detect the system setting and use different time format:

String format;

if (DateFormat.is24HourFormat(context)) {
  format = "MM/dd/yy, hh:mm";
}
else {
  format = "MM/dd/yy, h:mm aa";
}

DateTimeFormatter formatter = DateTimeFormat.forPattern(format);
formatter.print(new DateTime());