com.ibm.icu.text
public class SimpleDateFormat extends DateFormat
SimpleDateFormat
is a concrete class for formatting and
parsing dates in a locale-sensitive manner. It allows for formatting
(date -> text), parsing (text -> date), and normalization.
SimpleDateFormat
allows you to start by choosing
any user-defined patterns for date-time formatting. However, you
are encouraged to create a date-time formatter with either
getTimeInstance
, getDateInstance
, or
getDateTimeInstance
in DateFormat
. Each
of these class methods can return a date/time formatter initialized
with a default format pattern. You may modify the format pattern
using the applyPattern
methods as desired.
For more information on using these methods, see
DateFormat
.
Time Format Syntax:
To specify the time format use a time pattern string. In this pattern, all ASCII letters are reserved as pattern letters, which are defined as the following:
* These items are not supported by Java's SimpleDateFormat.Symbol Meaning Presentation Example ------ ------- ------------ ------- G era designator (Text) AD y† year (Number) 1996 Y* year (week of year) (Number) 1997 u* extended year (Number) 4601 M month in year (Text & Number) July & 07 d day in month (Number) 10 h hour in am/pm (1~12) (Number) 12 H hour in day (0~23) (Number) 0 m minute in hour (Number) 30 s second in minute (Number) 55 S fractional second (Number) 978 E day of week (Text) Tuesday e* day of week (local 1~7) (Text & Number) Tuesday & 2 D day in year (Number) 189 F day of week in month (Number) 2 (2nd Wed in July) w week in year (Number) 27 W week in month (Number) 2 a am/pm marker (Text) PM k hour in day (1~24) (Number) 24 K hour in am/pm (0~11) (Number) 0 z time zone (Text) Pacific Standard Time Z time zone (RFC 822) (Number) -0800 v time zone (generic) (Text) Pacific Time V time zone (location) (Text) United States (Los Angeles) g* Julian day (Number) 2451334 A* milliseconds in day (Number) 69540000 Q* quarter in year (Text & Number) Q1 & 01 c* stand alone day of week (Text & Number) Tuesday & 2 L* stand alone month (Text & Number) July & 07 q* stand alone quarter (Text & Number) Q1 & 01 ' escape for text (Delimiter) 'Date=' '' single quote (Literal) 'o''clock'
The count of pattern letters determine the format.
(Text): 4 or more pattern letters--use full form, < 4--use short or abbreviated form if one exists.
(Number): the minimum number of digits. Shorter numbers are zero-padded to this amount. Year is handled specially; that is, if the count of 'y' is 2, the Year will be truncated to 2 digits. (e.g., if "yyyy" produces "1997", "yy" produces "97".) Unlike other fields, fractional seconds are padded on the right with zero.
(Text & Number): 3 or over, use text, otherwise use number.
Any characters in the pattern that are not in the ranges of ['a'..'z'] and ['A'..'Z'] will be treated as quoted text. For instance, characters like ':', '.', ' ', '#' and '@' will appear in the resulting time text even they are not embraced within single quotes.
A pattern containing any invalid pattern letter will result in a thrown exception during formatting or parsing.
Examples Using the US Locale:
Code Sample:Format Pattern Result -------------- ------- "yyyy.MM.dd G 'at' HH:mm:ss vvvv" ->> 1996.07.10 AD at 15:08:56 Pacific Time "EEE, MMM d, ''yy" ->> Wed, July 10, '96 "h:mm a" ->> 12:08 PM "hh 'o''clock' a, zzzz" ->> 12 o'clock PM, Pacific Daylight Time "K:mm a, vvv" ->> 0:00 PM, PT "yyyyy.MMMMM.dd GGG hh:mm aaa" ->> 01996.July.10 AD 12:08 PM
In the example, the time valueSimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, "PST"); pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000); pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);
// Format the current time. SimpleDateFormat formatter = new SimpleDateFormat ("yyyy.MM.dd G 'at' hh:mm:ss a zzz"); Date currentTime_1 = new Date(); String dateString = formatter.format(currentTime_1);
// Parse the previous string back into a Date. ParsePosition pos = new ParsePosition(0); Date currentTime_2 = formatter.parse(dateString, pos);
currentTime_2
obtained from
parsing will be equal to currentTime_1
. However, they may not be
equal if the am/pm marker 'a' is left out from the format pattern while
the "hour in am/pm" pattern symbol is used. This information loss can
happen when formatting the time in PM.
When parsing a date string using the abbreviated year pattern ("yy"),
SimpleDateFormat must interpret the abbreviated year
relative to some century. It does this by adjusting dates to be
within 80 years before and 20 years after the time the SimpleDateFormat
instance is created. For example, using a pattern of "MM/dd/yy" and a
SimpleDateFormat instance created on Jan 1, 1997, the string
"01/11/12" would be interpreted as Jan 11, 2012 while the string "05/04/64"
would be interpreted as May 4, 1964.
During parsing, only strings consisting of exactly two digits, as defined by
UCharacter.isDigit(int)
, will be parsed into the default
century.
Any other numeric string, such as a one digit string, a three or more digit
string, or a two digit string that isn't all digits (for example, "-1"), is
interpreted literally. So "01/02/3" or "01/02/003" are parsed, using the
same pattern, as Jan 2, 3 AD. Likewise, "01/02/-3" is parsed as Jan 2, 4 BC.
If the year pattern does not have exactly two 'y' characters, the year is interpreted literally, regardless of the number of digits. So using the pattern "MM/dd/yyyy", "01/11/12" parses to Jan 11, 12 A.D.
When numeric fields abut one another directly, with no intervening delimiter characters, they constitute a run of abutting numeric fields. Such runs are parsed specially. For example, the format "HHmmss" parses the input text "123456" to 12:34:56, parses the input text "12345" to 1:23:45, and fails to parse "1234". In other words, the leftmost field of the run is flexible, while the others keep a fixed width. If the parse fails anywhere in the run, then the leftmost field is shortened by one character, and the entire run is parsed again. This is repeated until either the parse succeeds or the leftmost field is one character in length. If the parse still fails at that point, the parse of the run fails.
For time zones that have no names, use strings GMT+hours:minutes or GMT-hours:minutes.
The calendar defines what is the first day of the week, the first week of the year, whether hours are zero based or not (0 vs 12 or 24), and the time zone. There is one common decimal format to handle all the numbers; the digit count is handled programmatically according to the pattern.
Calendar
,
GregorianCalendar
,
TimeZone
,
DateFormat
,
DateFormatSymbols
,
DecimalFormat
,
Serialized FormDateFormat.Field
ABBR_MONTH, ABBR_MONTH_DAY, ABBR_MONTH_WEEKDAY_DAY, ABBR_STANDALONE_MONTH, AM_PM_FIELD, calendar, DATE_FIELD, DAY, DAY_OF_WEEK_FIELD, DAY_OF_WEEK_IN_MONTH_FIELD, DAY_OF_YEAR_FIELD, DEFAULT, DOW_LOCAL_FIELD, ERA_FIELD, EXTENDED_YEAR_FIELD, FIELD_COUNT, FRACTIONAL_SECOND_FIELD, FULL, HOUR, HOUR_GENERIC_TZ, HOUR_MINUTE, HOUR_MINUTE_GENERIC_TZ, HOUR_MINUTE_SECOND, HOUR_MINUTE_TZ, HOUR_OF_DAY0_FIELD, HOUR_OF_DAY1_FIELD, HOUR_TZ, HOUR0_FIELD, HOUR1_FIELD, HOUR24_MINUTE, HOUR24_MINUTE_SECOND, JULIAN_DAY_FIELD, LONG, MEDIUM, MILLISECOND_FIELD, MILLISECONDS_IN_DAY_FIELD, MINUTE_FIELD, MINUTE_SECOND, MONTH, MONTH_DAY, MONTH_FIELD, MONTH_WEEKDAY_DAY, NONE, NUM_MONTH, NUM_MONTH_DAY, NUM_MONTH_WEEKDAY_DAY, numberFormat, QUARTER_FIELD, RELATIVE, RELATIVE_DEFAULT, RELATIVE_FULL, RELATIVE_LONG, RELATIVE_MEDIUM, RELATIVE_SHORT, SECOND_FIELD, SHORT, STANDALONE_DAY_FIELD, STANDALONE_MONTH, STANDALONE_MONTH_FIELD, STANDALONE_QUARTER_FIELD, TIMEZONE_FIELD, TIMEZONE_GENERIC_FIELD, TIMEZONE_RFC_FIELD, TIMEZONE_SPECIAL_FIELD, WEEK_OF_MONTH_FIELD, WEEK_OF_YEAR_FIELD, YEAR, YEAR_ABBR_MONTH, YEAR_ABBR_MONTH_DAY, YEAR_ABBR_MONTH_WEEKDAY_DAY, YEAR_ABBR_QUARTER, YEAR_FIELD, YEAR_MONTH, YEAR_MONTH_DAY, YEAR_MONTH_WEEKDAY_DAY, YEAR_NUM_MONTH, YEAR_NUM_MONTH_DAY, YEAR_NUM_MONTH_WEEKDAY_DAY, YEAR_QUARTER, YEAR_WOY_FIELD
Constructor and Description |
---|
SimpleDateFormat()
Construct a SimpleDateFormat using the default pattern for the default
locale.
|
SimpleDateFormat(java.lang.String pattern)
Construct a SimpleDateFormat using the given pattern in the default
locale.
|
SimpleDateFormat(java.lang.String pattern,
DateFormatSymbols formatData)
Construct a SimpleDateFormat using the given pattern and
locale-specific symbol data.
|
SimpleDateFormat(java.lang.String pattern,
DateFormatSymbols formatData,
ULocale loc)
Deprecated.
This API is ICU internal only.
|
SimpleDateFormat(java.lang.String pattern,
java.util.Locale loc)
Construct a SimpleDateFormat using the given pattern and locale.
|
SimpleDateFormat(java.lang.String pattern,
java.lang.String override,
ULocale loc)
Construct a SimpleDateFormat using the given pattern , override and locale.
|
SimpleDateFormat(java.lang.String pattern,
ULocale loc)
Construct a SimpleDateFormat using the given pattern and locale.
|
Modifier and Type | Method and Description |
---|---|
void |
applyLocalizedPattern(java.lang.String pat)
Apply the given localized pattern string to this date format.
|
void |
applyPattern(java.lang.String pat)
Apply the given unlocalized pattern string to this date format.
|
java.lang.Object |
clone()
Overrides Cloneable
|
boolean |
equals(java.lang.Object obj)
Override equals.
|
java.lang.StringBuffer |
format(Calendar cal,
java.lang.StringBuffer toAppendTo,
java.text.FieldPosition pos)
Overrides DateFormat.
|
java.text.AttributedCharacterIterator |
formatToCharacterIterator(java.lang.Object obj)
Format the object to an attributed string, and return the corresponding iterator
Overrides superclass method.
|
java.util.Date |
get2DigitYearStart()
Returns the beginning date of the 100-year period 2-digit years are interpreted
as being within.
|
DateFormatSymbols |
getDateFormatSymbols()
Gets the date/time formatting data.
|
static SimpleDateFormat |
getInstance(Calendar.FormatConfiguration formatConfig)
Deprecated.
This API is ICU internal only.
|
protected NumberFormat |
getNumberFormat(char ch) |
protected DateFormatSymbols |
getSymbols()
Method for subclasses to access the DateFormatSymbols.
|
int |
hashCode()
Override hashCode.
|
java.lang.StringBuffer |
intervalFormatByAlgorithm(Calendar fromCalendar,
Calendar toCalendar,
java.lang.StringBuffer appendTo,
java.text.FieldPosition pos)
Format date interval by algorithm.
|
protected int |
matchQuarterString(java.lang.String text,
int start,
int field,
java.lang.String[] data,
Calendar cal)
Attempt to match the text at a given position against an array of quarter
strings.
|
protected int |
matchString(java.lang.String text,
int start,
int field,
java.lang.String[] data,
Calendar cal)
Attempt to match the text at a given position against an array of
strings.
|
void |
parse(java.lang.String text,
Calendar cal,
java.text.ParsePosition parsePos)
Overrides DateFormat
|
protected DateFormat.Field |
patternCharToDateFormatField(char ch)
Return a DateFormat.Field constant associated with the specified format pattern
character.
|
void |
set2DigitYearStart(java.util.Date startDate)
Sets the 100-year period 2-digit years will be interpreted as being in
to begin on the date the user specifies.
|
void |
setDateFormatSymbols(DateFormatSymbols newFormatSymbols)
Allows you to set the date/time formatting data.
|
void |
setNumberFormat(NumberFormat newNumberFormat)
Overrides superclass method
|
protected java.lang.String |
subFormat(char ch,
int count,
int beginOffset,
java.text.FieldPosition pos,
DateFormatSymbols fmtData,
Calendar cal)
Format a single field, given its pattern character.
|
protected void |
subFormat(java.lang.StringBuffer buf,
char ch,
int count,
int beginOffset,
java.text.FieldPosition pos,
Calendar cal)
Deprecated.
This API is ICU internal only.
|
protected int |
subParse(java.lang.String text,
int start,
char ch,
int count,
boolean obeyCount,
boolean allowNegative,
boolean[] ambiguousYear,
Calendar cal)
Protected method that converts one field of the input string into a
numeric field value in
cal . |
java.lang.String |
toLocalizedPattern()
Return a localized pattern string describing this date format.
|
java.lang.String |
toPattern()
Return a pattern string describing this date format.
|
protected java.lang.String |
zeroPaddingNumber(long value,
int minDigits,
int maxDigits)
Formats a number with the specified minimum and maximum number of digits.
|
protected void |
zeroPaddingNumber(NumberFormat nf,
java.lang.StringBuffer buf,
int value,
int minDigits,
int maxDigits)
Deprecated.
This API is ICU internal only.
|
format, format, format, getAvailableLocales, getAvailableULocales, getCalendar, getDateInstance, getDateInstance, getDateInstance, getDateInstance, getDateInstance, getDateInstance, getDateInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getInstance, getInstance, getInstance, getInstance, getNumberFormat, getPatternInstance, getPatternInstance, getPatternInstance, getPatternInstance, getPatternInstance, getTimeInstance, getTimeInstance, getTimeInstance, getTimeInstance, getTimeInstance, getTimeInstance, getTimeInstance, getTimeZone, isLenient, parse, parse, parseObject, setCalendar, setLenient, setTimeZone
public SimpleDateFormat()
DateFormat
public SimpleDateFormat(java.lang.String pattern)
public SimpleDateFormat(java.lang.String pattern, java.util.Locale loc)
public SimpleDateFormat(java.lang.String pattern, ULocale loc)
public SimpleDateFormat(java.lang.String pattern, java.lang.String override, ULocale loc)
public SimpleDateFormat(java.lang.String pattern, DateFormatSymbols formatData)
public SimpleDateFormat(java.lang.String pattern, DateFormatSymbols formatData, ULocale loc)
public static SimpleDateFormat getInstance(Calendar.FormatConfiguration formatConfig)
formatConfig
- the format configurationpublic void set2DigitYearStart(java.util.Date startDate)
startDate
- During parsing, two digit years will be placed in the range
startDate
to startDate + 100 years
.public java.util.Date get2DigitYearStart()
public java.lang.StringBuffer format(Calendar cal, java.lang.StringBuffer toAppendTo, java.text.FieldPosition pos)
Formats a date or time, which is the standard millis since January 1, 1970, 00:00:00 GMT.
Example: using the US locale: "yyyy.MM.dd G 'at' HH:mm:ss zzz" ->> 1996.07.10 AD at 15:08:56 PDT
format
in class DateFormat
cal
- the calendar whose date-time value is to be formatted into a date-time stringtoAppendTo
- where the new date-time text is to be appendedpos
- the formatting position. On input: an alignment field,
if desired. On output: the offsets of the alignment field.DateFormat
protected DateFormat.Field patternCharToDateFormatField(char ch)
ch
- The pattern characterprotected java.lang.String subFormat(char ch, int count, int beginOffset, java.text.FieldPosition pos, DateFormatSymbols fmtData, Calendar cal) throws java.lang.IllegalArgumentException
ch
- the pattern charactercount
- the number of times ch is repeated in the patternbeginOffset
- the offset of the output string at the start of
this field; used to set pos when appropriatepos
- receives the position of a field, when appropriatefmtData
- the symbols for this formatterjava.lang.IllegalArgumentException
protected void subFormat(java.lang.StringBuffer buf, char ch, int count, int beginOffset, java.text.FieldPosition pos, Calendar cal)
protected void zeroPaddingNumber(NumberFormat nf, java.lang.StringBuffer buf, int value, int minDigits, int maxDigits)
public void setNumberFormat(NumberFormat newNumberFormat)
setNumberFormat
in class DateFormat
newNumberFormat
- the given new NumberFormat.protected java.lang.String zeroPaddingNumber(long value, int minDigits, int maxDigits)
public void parse(java.lang.String text, Calendar cal, java.text.ParsePosition parsePos)
parse
in class DateFormat
text
- The date/time string to be parsedcal
- The calendar into which parsed data will be stored.
In general, this should be cleared before calling this
method. If this parse fails, the calendar may still
have been modified. When the calendar type is different
from the internal calendar held by this DateFormat
instance, calendar field values will be parsed based
on the internal calendar initialized with the time and
the time zone taken from this calendar, then the
parse result (time in milliseconds and time zone) will
be set back to this calendar.parsePos
- 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.DateFormat
protected int matchString(java.lang.String text, int start, int field, java.lang.String[] data, Calendar cal)
cal
is set to the index
of the best match, if there is one.text
- the time text being parsed.start
- where to start parsing.field
- the date field being parsed.data
- the string array to parsed.cal
field field
to the index
of the best match, if matching succeeded.protected int matchQuarterString(java.lang.String text, int start, int field, java.lang.String[] data, Calendar cal)
cal
is set to the index
of the best match, if there is one.text
- the time text being parsed.start
- where to start parsing.field
- the date field being parsed.data
- the string array to parsed.cal
field field
to the index
of the best match, if matching succeeded.protected int subParse(java.lang.String text, int start, char ch, int count, boolean obeyCount, boolean allowNegative, boolean[] ambiguousYear, Calendar cal)
cal
. Returns -start (for
ParsePosition) if failed. Subclasses may override this method to
modify or add parsing capabilities.text
- the time text to be parsed.start
- where to start parsing.ch
- the pattern character for the date field text to be parsed.count
- the count of a pattern character.obeyCount
- if true, then the next field directly abuts this one,
and we should use the count to know when to stop parsing.ambiguousYear
- return parameter; upon return, if ambiguousYear[0]
is true, then a two-digit year was parsed and may need to be readjusted.cal
with the parsed
value.public java.lang.String toPattern()
public java.lang.String toLocalizedPattern()
public void applyPattern(java.lang.String pat)
public void applyLocalizedPattern(java.lang.String pat)
public DateFormatSymbols getDateFormatSymbols()
public void setDateFormatSymbols(DateFormatSymbols newFormatSymbols)
newFormatSymbols
- the new symbolsprotected DateFormatSymbols getSymbols()
public java.lang.Object clone()
clone
in class DateFormat
public int hashCode()
hashCode
in class DateFormat
public boolean equals(java.lang.Object obj)
equals
in class DateFormat
public java.text.AttributedCharacterIterator formatToCharacterIterator(java.lang.Object obj)
formatToCharacterIterator
in class java.text.Format
obj
- The object to formatAttributedCharacterIterator
describing the formatted value.public final java.lang.StringBuffer intervalFormatByAlgorithm(Calendar fromCalendar, Calendar toCalendar, java.lang.StringBuffer appendTo, java.text.FieldPosition pos) throws java.lang.IllegalArgumentException
fromCalendar
- calendar set to the from date in date interval
to be formatted into date interval stirngtoCalendar
- calendar set to the to date in date interval
to be formatted into date interval stirngappendTo
- Output parameter to receive result.
Result is appended to existing contents.pos
- On input: an alignment field, if desired.
On output: the offsets of the alignment field.java.lang.IllegalArgumentException
- when there is non-recognized
pattern letterprotected NumberFormat getNumberFormat(char ch)
Copyright (c) 2009 IBM Corporation and others.