public abstract class DateFormat extends Format
DateFormat is an abstract class for date/time formatting subclasses which
 formats and parses dates or time in a language-independent manner.
 The date/time formatting subclass, such as SimpleDateFormat, allows for
 formatting (i.e., date -> text), parsing (text -> date), and
 normalization.  The date is represented as a Date object or
 as the milliseconds since January 1, 1970, 00:00:00 GMT.
 DateFormat provides many class methods for obtaining default date/time
 formatters based on the default or a given locale and a number of formatting
 styles. The formatting styles include FULL, LONG, MEDIUM, and SHORT. More
 detail and examples of using these styles are provided in the method
 descriptions.
 
DateFormat helps you to format and parse dates for any locale.
 Your code can be completely independent of the locale conventions for
 months, days of the week, or even the calendar format: lunar vs. solar.
 
To format a date for the current Locale, use one of the static factory methods:
myString = DateFormat.getDateInstance().format(myDate);
If you are formatting multiple dates, it is more efficient to get the format and use it multiple times so that the system doesn't have to fetch the information about the local language and country conventions multiple times.
  DateFormat df = DateFormat.getDateInstance();
  for (int i = 0; i < myDate.length; ++i) {
    output.println(df.format(myDate[i]) + "; ");
  }
 
 To format a date for a different Locale, specify it in the
 call to getDateInstance().
 
DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE);
You can use a DateFormat to parse also.
myDate = df.parse(myString);
Use getDateInstance to get the normal date format for that country.
 There are other static factory methods available.
 Use getTimeInstance to get the time format for that country.
 Use getDateTimeInstance to get a date and time format. You can pass in
 different options to these factory methods to control the length of the
 result; from SHORT to MEDIUM to LONG to FULL. The exact result depends
 on the locale, but generally:
 
SHORT is completely numeric, such as 12.13.52 or 3:30pm
 MEDIUM is longer, such as Jan 12, 1952
 LONG is longer, such as January 12, 1952 or 3:30:32pm
 FULL is pretty completely specified, such as
 Tuesday, April 12, 1952 AD or 3:30:42pm PST.
 You can also set the time zone on the format if you wish.
 If you want even more control over the format or parsing,
 (or want to give your users more control),
 you can try casting the DateFormat you get from the factory methods
 to a SimpleDateFormat. This will work for the majority
 of countries; just remember to put it in a try block in case you
 encounter an unusual one.
 
You can also use forms of the parse and format methods with
 ParsePosition and FieldPosition to
 allow you to
 
Date formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.
Format, 
NumberFormat, 
SimpleDateFormat, 
Calendar, 
GregorianCalendar, 
TimeZone, 
Serialized Form| Modifier and Type | Class and Description | 
|---|---|
| static class  | DateFormat.FieldDefines constants that are used as attribute keys in the
  AttributedCharacterIteratorreturned
 fromDateFormat.formatToCharacterIteratorand as
 field identifiers inFieldPosition. | 
| Modifier and Type | Field and Description | 
|---|---|
| static int | AM_PM_FIELDUseful constant for AM_PM field alignment. | 
| protected Calendar | calendarThe  Calendarinstance used for calculating the date-time fields
 and the instant of time. | 
| static int | DATE_FIELDUseful constant for DATE field alignment. | 
| static int | DAY_OF_WEEK_FIELDUseful constant for DAY_OF_WEEK field alignment. | 
| static int | DAY_OF_WEEK_IN_MONTH_FIELDUseful constant for DAY_OF_WEEK_IN_MONTH field alignment. | 
| static int | DAY_OF_YEAR_FIELDUseful constant for DAY_OF_YEAR field alignment. | 
| static int | DEFAULTConstant for default style pattern. | 
| static int | ERA_FIELDUseful constant for ERA field alignment. | 
| static int | FULLConstant for full style pattern. | 
| static int | HOUR_OF_DAY0_FIELDUseful constant for zero-based HOUR_OF_DAY field alignment. | 
| static int | HOUR_OF_DAY1_FIELDUseful constant for one-based HOUR_OF_DAY field alignment. | 
| static int | HOUR0_FIELDUseful constant for zero-based HOUR field alignment. | 
| static int | HOUR1_FIELDUseful constant for one-based HOUR field alignment. | 
| static int | LONGConstant for long style pattern. | 
| static int | MEDIUMConstant for medium style pattern. | 
| static int | MILLISECOND_FIELDUseful constant for MILLISECOND field alignment. | 
| static int | MINUTE_FIELDUseful constant for MINUTE field alignment. | 
| static int | MONTH_FIELDUseful constant for MONTH field alignment. | 
| protected NumberFormat | numberFormatThe number formatter that  DateFormatuses to format numbers
 in dates and times. | 
| static int | SECOND_FIELDUseful constant for SECOND field alignment. | 
| static int | SHORTConstant for short style pattern. | 
| static int | TIMEZONE_FIELDUseful constant for TIMEZONE field alignment. | 
| static int | WEEK_OF_MONTH_FIELDUseful constant for WEEK_OF_MONTH field alignment. | 
| static int | WEEK_OF_YEAR_FIELDUseful constant for WEEK_OF_YEAR field alignment. | 
| static int | YEAR_FIELDUseful constant for YEAR field alignment. | 
| Modifier | Constructor and Description | 
|---|---|
| protected  | DateFormat()Create a new date format. | 
| Modifier and Type | Method and Description | 
|---|---|
| Object | clone()Overrides Cloneable | 
| boolean | equals(Object obj)Overrides equals | 
| String | format(Date date)Formats a Date into a date/time string. | 
| abstract StringBuffer | format(Date date,
      StringBuffer toAppendTo,
      FieldPosition fieldPosition)Formats a Date into a date/time string. | 
| StringBuffer | format(Object obj,
      StringBuffer toAppendTo,
      FieldPosition fieldPosition)Overrides Format. | 
| static Locale[] | getAvailableLocales()Returns an array of all locales for which the
  get*Instancemethods of this class can return
 localized instances. | 
| Calendar | getCalendar()Gets the calendar associated with this date/time formatter. | 
| static DateFormat | getDateInstance()Gets the date formatter with the default formatting style
 for the default locale. | 
| static DateFormat | getDateInstance(int style)Gets the date formatter with the given formatting style
 for the default locale. | 
| static DateFormat | getDateInstance(int style,
               Locale aLocale)Gets the date formatter with the given formatting style
 for the given locale. | 
| static DateFormat | getDateTimeInstance()Gets the date/time formatter with the default formatting style
 for the default locale. | 
| static DateFormat | getDateTimeInstance(int dateStyle,
                   int timeStyle)Gets the date/time formatter with the given date and time
 formatting styles for the default locale. | 
| static DateFormat | getDateTimeInstance(int dateStyle,
                   int timeStyle,
                   Locale aLocale)Gets the date/time formatter with the given formatting styles
 for the given locale. | 
| static DateFormat | getInstance()Get a default date/time formatter that uses the SHORT style for both the
 date and the time. | 
| NumberFormat | getNumberFormat()Gets the number formatter which this date/time formatter uses to
 format and parse a time. | 
| static DateFormat | getTimeInstance()Gets the time formatter with the default formatting style
 for the default locale. | 
| static DateFormat | getTimeInstance(int style)Gets the time formatter with the given formatting style
 for the default locale. | 
| static DateFormat | getTimeInstance(int style,
               Locale aLocale)Gets the time formatter with the given formatting style
 for the given locale. | 
| TimeZone | getTimeZone()Gets the time zone. | 
| int | hashCode()Overrides hashCode | 
| boolean | isLenient()Tell whether date/time parsing is to be lenient. | 
| Date | parse(String source)Parses text from the beginning of the given string to produce a date. | 
| abstract Date | parse(String source,
     ParsePosition pos)Parse a date/time string according to the given parse position. | 
| Object | parseObject(String source,
           ParsePosition pos)Parses text from a string to produce a  Date. | 
| void | setCalendar(Calendar newCalendar)Set the calendar to be used by this date format. | 
| void | setLenient(boolean lenient)Specify whether or not date/time parsing is to be lenient. | 
| void | setNumberFormat(NumberFormat newNumberFormat)Allows you to set the number formatter. | 
| void | setTimeZone(TimeZone zone)Sets the time zone for the calendar of this  DateFormatobject. | 
format, formatToCharacterIterator, parseObjectprotected Calendar calendar
protected NumberFormat numberFormat
DateFormat uses to format numbers
 in dates and times.  Subclasses should initialize this to a number format
 appropriate for the locale associated with this DateFormat.public static final int ERA_FIELD
public static final int YEAR_FIELD
public static final int MONTH_FIELD
public static final int DATE_FIELD
public static final int HOUR_OF_DAY1_FIELD
public static final int HOUR_OF_DAY0_FIELD
public static final int MINUTE_FIELD
public static final int SECOND_FIELD
public static final int MILLISECOND_FIELD
public static final int DAY_OF_WEEK_FIELD
public static final int DAY_OF_YEAR_FIELD
public static final int DAY_OF_WEEK_IN_MONTH_FIELD
public static final int WEEK_OF_YEAR_FIELD
public static final int WEEK_OF_MONTH_FIELD
public static final int AM_PM_FIELD
public static final int HOUR1_FIELD
public static final int HOUR0_FIELD
public static final int TIMEZONE_FIELD
public static final int FULL
public static final int LONG
public static final int MEDIUM
public static final int SHORT
public static final int DEFAULT
public final StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition fieldPosition)
format in class Formatobj - must be a Number or a Date.toAppendTo - the string buffer for the returning time string.fieldPosition - keeps track of the position of the field
 within the returned string.
 On input: an alignment field,
 if desired. On output: the offsets of the alignment field. For
 example, given a time text "1996.07.10 AD at 15:08:56 PDT",
 if the given fieldPosition is DateFormat.YEAR_FIELD, the
 begin index and end index of fieldPosition will be set to
 0 and 4, respectively.
 Notice that if the same time field appears
 more than once in a pattern, the fieldPosition will be set for the first
 occurrence of that time field. For instance, formatting a Date to
 the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
 "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
 the begin index and end index of fieldPosition will be set to
 5 and 8, respectively, for the first occurrence of the timezone
 pattern character 'z'.Formatpublic abstract StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition)
date - a Date to be formatted into a date/time string.toAppendTo - the string buffer for the returning date/time string.fieldPosition - keeps track of the position of the field
 within the returned string.
 On input: an alignment field,
 if desired. On output: the offsets of the alignment field. For
 example, given a time text "1996.07.10 AD at 15:08:56 PDT",
 if the given fieldPosition is DateFormat.YEAR_FIELD, the
 begin index and end index of fieldPosition will be set to
 0 and 4, respectively.
 Notice that if the same time field appears
 more than once in a pattern, the fieldPosition will be set for the first
 occurrence of that time field. For instance, formatting a Date to
 the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
 "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
 the begin index and end index of fieldPosition will be set to
 5 and 8, respectively, for the first occurrence of the timezone
 pattern character 'z'.public final String format(Date date)
date - the time value to be formatted into a time string.public Date parse(String source) throws ParseException
 See the parse(String, ParsePosition) method for more information
 on date parsing.
source - A String whose beginning should be parsed.Date parsed from the string.ParseException - if the beginning of the specified string
            cannot be parsed.public abstract Date parse(String source, ParsePosition pos)
"07/10/96 4:5 PM, PDT" will be parsed into a Date
 that is equivalent to Date(837039900000L).
  By default, parsing is lenient: If the input is not in the form used
 by this object's format method but can still be parsed as a date, then
 the parse succeeds.  Clients may insist on strict adherence to the
 format by calling setLenient(false).
 
This parsing operation uses the calendar to produce
 a Date. As a result, the calendar's date-time
 fields and the TimeZone value may have been
 overwritten, depending on subclass implementations. Any TimeZone value that has previously been set by a call to
 setTimeZone may need
 to be restored for further operations.
source - The date/time string to be parsedpos - On input, the position at which to start parsing; on
              output, the position at which parsing terminated, or the
              start position if the parse failed.Date, or null if the input could not be parsedpublic Object parseObject(String source, ParsePosition pos)
Date.
 
 The method attempts to parse text starting at the index given by
 pos.
 If parsing succeeds, then the index of pos is updated
 to the index after the last character used (parsing does not necessarily
 use all characters up to the end of the string), and the parsed
 date is returned. The updated pos can be used to
 indicate the starting point for the next call to this method.
 If an error occurs, then the index of pos is not
 changed, the error index of pos is set to the index of
 the character where the error occurred, and null is returned.
 
 See the parse(String, ParsePosition) method for more information
 on date parsing.
parseObject in class Formatsource - A String, part of which should be parsed.pos - A ParsePosition object with index and error
            index information as described above.Date parsed from the string. In case of
         error, returns null.NullPointerException - if pos is null.public static final DateFormat getTimeInstance()
public static final DateFormat getTimeInstance(int style)
style - the given formatting style. For example,
 SHORT for "h:mm a" in the US locale.public static final DateFormat getTimeInstance(int style, Locale aLocale)
style - the given formatting style. For example,
 SHORT for "h:mm a" in the US locale.aLocale - the given locale.public static final DateFormat getDateInstance()
public static final DateFormat getDateInstance(int style)
style - the given formatting style. For example,
 SHORT for "M/d/yy" in the US locale.public static final DateFormat getDateInstance(int style, Locale aLocale)
style - the given formatting style. For example,
 SHORT for "M/d/yy" in the US locale.aLocale - the given locale.public static final DateFormat getDateTimeInstance()
public static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle)
dateStyle - the given date formatting style. For example,
 SHORT for "M/d/yy" in the US locale.timeStyle - the given time formatting style. For example,
 SHORT for "h:mm a" in the US locale.public static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)
dateStyle - the given date formatting style.timeStyle - the given time formatting style.aLocale - the given locale.public static final DateFormat getInstance()
public static Locale[] getAvailableLocales()
get*Instance methods of this class can return
 localized instances.
 The returned array represents the union of locales supported by the Java
 runtime and by installed
 DateFormatProvider implementations.
 It must contain at least a Locale instance equal to
 Locale.US.DateFormat instances are available.public void setCalendar(Calendar newCalendar)
Any TimeZone and leniency values that have previously been set are
 overwritten by newCalendar's values.
newCalendar - the new Calendar to be used by the date formatpublic Calendar getCalendar()
public void setNumberFormat(NumberFormat newNumberFormat)
newNumberFormat - the given new NumberFormat.public NumberFormat getNumberFormat()
public void setTimeZone(TimeZone zone)
DateFormat object.
 This method is equivalent to the following call.
 getCalendar().setTimeZone(zone)
The TimeZone set by this method is overwritten by a
 setCalendar call.
 
The TimeZone set by this method may be overwritten as
 a result of a call to the parse method.
zone - the given new time zone.public TimeZone getTimeZone()
getCalendar().getTimeZone()
public void setLenient(boolean lenient)
This method is equivalent to the following call.
getCalendar().setLenient(lenient)
This leniency value is overwritten by a call to setCalendar().
lenient - when true, parsing is lenientCalendar.setLenient(boolean)public boolean isLenient()
getCalendar().isLenient()
true if the calendar is lenient;
         false otherwise.Calendar.isLenient()public int hashCode()
hashCode in class ObjectObject.equals(java.lang.Object), 
System.identityHashCode(java.lang.Object)public boolean equals(Object obj)
equals in class Objectobj - the reference object with which to compare.true if this object is the same as the obj
          argument; false otherwise.Object.hashCode(), 
HashMap Submit a bug or feature 
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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