Using Predefined Formats
Version note: This Date and Time section uses the date and time APIs in the java.util package. The java.time APIs, available in the JDK 8 release, provides a comprehensive date and time model that offers significant improvements over the java.util classes. The java.time APIs are described in the Date Time trail. The Legacy Date-Time Code page might be of particular interest.
The DateFormat
class allows you to format dates and times with predefined styles in a locale-sensitive manner. The sections that follow demonstrate how to use the DateFormat
class with a program called DateFormatDemo.java
.
Dates
Formatting dates with the DateFormat
class is a two-step process. First, you create a formatter with the getDateInstance
method. Second, you invoke the format
method, which returns a String
containing the formatted date. The following example formats today's date by calling these two methods:
Date today; String dateOut; DateFormat dateFormatter; dateFormatter = DateFormat.getDateInstance(DateFormat.DEFAULT, currentLocale); today = new Date(); dateOut = dateFormatter.format(today); System.out.println(dateOut + " " + currentLocale.toString());
The output generated by this code follows. Notice that the formats of the dates vary with Locale
. Since DateFormat
is locale-sensitive, it takes care of the formatting details for each Locale
.
30 juin 2009 fr_FR 30.06.2009 de_DE Jun 30, 2009 en_US
The preceding code example specified the DEFAULT
formatting style. The DEFAULT
style is just one of the predefined formatting styles that the DateFormat
class provides, as follows:
- DEFAULT
- SHORT
- MEDIUM
- LONG
- FULL
The following table shows how dates are formatted for each style with the U.S. and French locales:
Style | U.S. Locale | French Locale |
---|---|---|
DEFAULT |
Jun 30, 2009 | 30 juin 2009 |
SHORT |
6/30/09 | 30/06/09 |
MEDIUM |
Jun 30, 2009 | 30 juin 2009 |
LONG |
June 30, 2009 | 30 juin 2009 |
FULL |
Tuesday, June 30, 2009 | mardi 30 juin 2009 |
Times
Date
objects represent both dates and times. Formatting times with the DateFormat
class is similar to formatting dates, except that you create the formatter with the getTimeInstance
method, as follows:
DateFormat timeFormatter = DateFormat.getTimeInstance(DateFormat.DEFAULT, currentLocale);
The table that follows shows the various predefined format styles for the U.S. and German locales:
Style | U.S. Locale | German Locale |
---|---|---|
DEFAULT |
7:03:47 AM | 7:03:47 |
SHORT |
7:03 AM | 07:03 |
MEDIUM |
7:03:47 AM | 07:03:07 |
LONG |
7:03:47 AM PDT | 07:03:45 PDT |
FULL |
7:03:47 AM PDT | 7.03 Uhr PDT |
Both Dates and Times
To display a date and time in the same String
, create the formatter with the getDateTimeInstance
method. The first parameter is the date style, and the second is the time style. The third parameter is the Locale
. Here's a quick example:
DateFormat formatter = DateFormat.getDateTimeInstance( DateFormat.LONG, DateFormat.LONG, currentLocale);
The following table shows the date and time formatting styles for the U.S. and French locales:
Style | U.S. Locale | French Locale |
---|---|---|
DEFAULT |
Jun 30, 2009 7:03:47 AM | 30 juin 2009 07:03:47 |
SHORT |
6/30/09 7:03 AM | 30/06/09 07:03 |
MEDIUM |
Jun 30, 2009 7:03:47 AM | 30 juin 2009 07:03:47 |
LONG |
June 30, 2009 7:03:47 AM PDT | 30 juin 2009 07:03:47 PDT |
FULL |
Tuesday, June 30, 2009 7:03:47 AM PDT | mardi 30 juin 2009 07 h 03 PDT |