- java.lang.Object
-
- java.text.Format
-
- java.text.DateFormat
-
- java.text.SimpleDateFormat
-
- All Implemented Interfaces:
- Serializable, Cloneable
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 eithergetTimeInstance
,getDateInstance
, orgetDateTimeInstance
inDateFormat
. Each of these class methods can return a date/time formatter initialized with a default format pattern. You may modify the format pattern using theapplyPattern
methods as desired. For more information on using these methods, seeDateFormat
.Date and Time Patterns
Date and time formats are specified by date and time pattern strings. Within date and time pattern strings, unquoted letters from
'A'
to'Z'
and from'a'
to'z'
are interpreted as pattern letters representing the components of a date or time string. Text can be quoted using single quotes ('
) to avoid interpretation."''"
represents a single quote. All other characters are not interpreted; they're simply copied into the output string during formatting or matched against the input string during parsing.The following pattern letters are defined (all other characters from
'A'
to'Z'
and from'a'
to'z'
are reserved):Letter Date or Time Component Presentation Examples G
Era designator Text AD
y
Year Year 1996
;96
Y
Week year Year 2009
;09
M
Month in year Month July
;Jul
;07
w
Week in year Number 27
W
Week in month Number 2
D
Day in year Number 189
d
Day in month Number 10
F
Day of week in month Number 2
E
Day name in week Text Tuesday
;Tue
u
Day number of week (1 = Monday, ..., 7 = Sunday) Number 1
a
Am/pm marker Text PM
H
Hour in day (0-23) Number 0
k
Hour in day (1-24) Number 24
K
Hour in am/pm (0-11) Number 0
h
Hour in am/pm (1-12) Number 12
m
Minute in hour Number 30
s
Second in minute Number 55
S
Millisecond Number 978
z
Time zone General time zone Pacific Standard Time
;PST
;GMT-08:00
Z
Time zone RFC 822 time zone -0800
X
Time zone ISO 8601 time zone -08
;-0800
;-08:00
- Text:
For formatting, if the number of pattern letters is 4 or more,
the full form is used; otherwise a short or abbreviated form
is used if available.
For parsing, both forms are accepted, independent of the number
of pattern letters.
- Number:
For formatting, the number of pattern letters is the minimum
number of digits, and shorter numbers are zero-padded to this amount.
For parsing, the number of pattern letters is ignored unless
it's needed to separate two adjacent fields.
- Year:
If the formatter's
Calendar
is the Gregorian calendar, the following rules are applied.
- For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted as a number.
- For parsing, if the number of pattern letters is more than 2, 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.
- For parsing with the abbreviated year pattern ("y" or "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 theSimpleDateFormat
instance is created. For example, using a pattern of "MM/dd/yy" and aSimpleDateFormat
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 byCharacter.isDigit(char)
, 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 week year'Y'
is specified and the calendar doesn't support any week years, the calendar year ('y'
) is used instead. The support of week years can be tested with a call togetCalendar()
.isWeekDateSupported()
. - Month:
If the number of pattern letters is 3 or more, the month is
interpreted as text; otherwise,
it is interpreted as a number.
- General time zone:
Time zones are interpreted as text if they have
names. For time zones representing a GMT offset value, the
following syntax is used:
GMTOffsetTimeZone:
Hours must be between 0 and 23, and Minutes must be between 00 and 59. The format is locale independent and digits must be taken from the Basic Latin block of the Unicode standard.GMT
Sign Hours:
Minutes Sign: one of+ -
Hours: Digit Digit Digit Minutes: Digit Digit Digit: one of0 1 2 3 4 5 6 7 8 9
For parsing, RFC 822 time zones are also accepted.
- RFC 822 time zone:
For formatting, the RFC 822 4-digit time zone format is used:
RFC822TimeZone: Sign TwoDigitHours Minutes TwoDigitHours: Digit Digit
TwoDigitHours must be between 00 and 23. Other definitions are as for general time zones.For parsing, general time zones are also accepted.
- ISO 8601 Time zone:
The number of pattern letters designates the format for both formatting
and parsing as follows:
ISO8601TimeZone: OneLetterISO8601TimeZone TwoLetterISO8601TimeZone ThreeLetterISO8601TimeZone OneLetterISO8601TimeZone: Sign TwoDigitHours
Other definitions are as for general time zones or RFC 822 time zones.Z
TwoLetterISO8601TimeZone: Sign TwoDigitHours MinutesZ
ThreeLetterISO8601TimeZone: Sign TwoDigitHours:
MinutesZ
For formatting, if the offset value from GMT is 0,
"Z"
is produced. If the number of pattern letters is 1, any fraction of an hour is ignored. For example, if the pattern is"X"
and the time zone is"GMT+05:30"
,"+05"
is produced.For parsing,
"Z"
is parsed as the UTC time zone designator. General time zones are not accepted.If the number of pattern letters is 4 or more,
IllegalArgumentException
is thrown when constructing aSimpleDateFormat
or applying a pattern.
SimpleDateFormat
also supports localized date and time pattern strings. In these strings, the pattern letters described above may be replaced with other, locale dependent, pattern letters.SimpleDateFormat
does not deal with the localization of text other than the pattern letters; that's up to the client of the class.Examples
The following examples show how date and time patterns are interpreted in the U.S. locale. The given date and time are 2001-07-04 12:08:56 local time in the U.S. Pacific Time time zone.Date and Time Pattern Result "yyyy.MM.dd G 'at' HH:mm:ss z"
2001.07.04 AD at 12:08:56 PDT
"EEE, MMM d, ''yy"
Wed, Jul 4, '01
"h:mm a"
12:08 PM
"hh 'o''clock' a, zzzz"
12 o'clock PM, Pacific Daylight Time
"K:mm a, z"
0:08 PM, PDT
"yyyyy.MMMMM.dd GGG hh:mm aaa"
02001.July.04 AD 12:08 PM
"EEE, d MMM yyyy HH:mm:ss Z"
Wed, 4 Jul 2001 12:08:56 -0700
"yyMMddHHmmssZ"
010704120856-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSZ"
2001-07-04T12:08:56.235-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX"
2001-07-04T12:08:56.235-07:00
"YYYY-'W'ww-u"
2001-W27-3
Synchronization
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.
- See Also:
- Java Tutorial,
Calendar
,TimeZone
,DateFormat
,DateFormatSymbols
, Serialized Form
-
-
Nested Class Summary
-
Nested classes/interfaces inherited from class java.text.DateFormat
DateFormat.Field
-
-
Field Summary
-
Fields inherited from class java.text.DateFormat
AM_PM_FIELD, calendar, DATE_FIELD, DAY_OF_WEEK_FIELD, DAY_OF_WEEK_IN_MONTH_FIELD, DAY_OF_YEAR_FIELD, DEFAULT, ERA_FIELD, FULL, HOUR_OF_DAY0_FIELD, HOUR_OF_DAY1_FIELD, HOUR0_FIELD, HOUR1_FIELD, LONG, MEDIUM, MILLISECOND_FIELD, MINUTE_FIELD, MONTH_FIELD, numberFormat, SECOND_FIELD, SHORT, TIMEZONE_FIELD, WEEK_OF_MONTH_FIELD, WEEK_OF_YEAR_FIELD, YEAR_FIELD
-
-
Constructor Summary
Constructors Constructor and Description SimpleDateFormat()
Constructs aSimpleDateFormat
using the default pattern and date format symbols for the default locale.SimpleDateFormat(String pattern)
Constructs aSimpleDateFormat
using the given pattern and the default date format symbols for the default locale.SimpleDateFormat(String pattern, DateFormatSymbols formatSymbols)
Constructs aSimpleDateFormat
using the given pattern and date format symbols.SimpleDateFormat(String pattern, Locale locale)
Constructs aSimpleDateFormat
using the given pattern and the default date format symbols for the given locale.
-
Method Summary
Methods Modifier and Type Method and Description void
applyLocalizedPattern(String pattern)
Applies the given localized pattern string to this date format.void
applyPattern(String pattern)
Applies the given pattern string to this date format.Object
clone()
Creates a copy of thisSimpleDateFormat
.boolean
equals(Object obj)
Compares the given object with thisSimpleDateFormat
for equality.StringBuffer
format(Date date, StringBuffer toAppendTo, FieldPosition pos)
Formats the givenDate
into a date/time string and appends the result to the givenStringBuffer
.AttributedCharacterIterator
formatToCharacterIterator(Object obj)
Formats an Object producing anAttributedCharacterIterator
.Date
get2DigitYearStart()
Returns the beginning date of the 100-year period 2-digit years are interpreted as being within.DateFormatSymbols
getDateFormatSymbols()
Gets a copy of the date and time format symbols of this date format.int
hashCode()
Returns the hash code value for thisSimpleDateFormat
object.Date
parse(String text, ParsePosition pos)
Parses text from a string to produce aDate
.void
set2DigitYearStart(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)
Sets the date and time format symbols of this date format.String
toLocalizedPattern()
Returns a localized pattern string describing this date format.String
toPattern()
Returns a pattern string describing this date format.-
Methods inherited from class java.text.DateFormat
format, format, getAvailableLocales, getCalendar, getDateInstance, getDateInstance, getDateInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getInstance, getNumberFormat, getTimeInstance, getTimeInstance, getTimeInstance, getTimeZone, isLenient, parse, parseObject, setCalendar, setLenient, setNumberFormat, setTimeZone
-
Methods inherited from class java.text.Format
format, parseObject
-
-
-
-
Constructor Detail
-
SimpleDateFormat
public SimpleDateFormat()
Constructs aSimpleDateFormat
using the default pattern and date format symbols for the default locale. Note: This constructor may not support all locales. For full coverage, use the factory methods in theDateFormat
class.
-
SimpleDateFormat
public SimpleDateFormat(String pattern)
Constructs aSimpleDateFormat
using the given pattern and the default date format symbols for the default locale. Note: This constructor may not support all locales. For full coverage, use the factory methods in theDateFormat
class.- Parameters:
pattern
- the pattern describing the date and time format- Throws:
NullPointerException
- if the given pattern is nullIllegalArgumentException
- if the given pattern is invalid
-
SimpleDateFormat
public SimpleDateFormat(String pattern, Locale locale)
Constructs aSimpleDateFormat
using the given pattern and the default date format symbols for the given locale. Note: This constructor may not support all locales. For full coverage, use the factory methods in theDateFormat
class.- Parameters:
pattern
- the pattern describing the date and time formatlocale
- the locale whose date format symbols should be used- Throws:
NullPointerException
- if the given pattern or locale is nullIllegalArgumentException
- if the given pattern is invalid
-
SimpleDateFormat
public SimpleDateFormat(String pattern, DateFormatSymbols formatSymbols)
Constructs aSimpleDateFormat
using the given pattern and date format symbols.- Parameters:
pattern
- the pattern describing the date and time formatformatSymbols
- the date format symbols to be used for formatting- Throws:
NullPointerException
- if the given pattern or formatSymbols is nullIllegalArgumentException
- if the given pattern is invalid
-
-
Method Detail
-
set2DigitYearStart
public void set2DigitYearStart(Date startDate)
Sets the 100-year period 2-digit years will be interpreted as being in to begin on the date the user specifies.- Parameters:
startDate
- During parsing, two digit years will be placed in the rangestartDate
tostartDate + 100 years
.- Since:
- 1.2
- See Also:
get2DigitYearStart()
-
get2DigitYearStart
public Date get2DigitYearStart()
Returns the beginning date of the 100-year period 2-digit years are interpreted as being within.- Returns:
- the start of the 100-year period into which two digit years are parsed
- Since:
- 1.2
- See Also:
set2DigitYearStart(java.util.Date)
-
format
public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition pos)
Formats the givenDate
into a date/time string and appends the result to the givenStringBuffer
.- Specified by:
format
in classDateFormat
- Parameters:
date
- the date-time value to be formatted into a date-time string.toAppendTo
- where the new date-time text is to be appended.pos
- the formatting position. On input: an alignment field, if desired. On output: the offsets of the alignment field.- Returns:
- the formatted date-time string.
- Throws:
NullPointerException
- if the givendate
isnull
.
-
formatToCharacterIterator
public AttributedCharacterIterator formatToCharacterIterator(Object obj)
Formats an Object producing anAttributedCharacterIterator
. You can use the returnedAttributedCharacterIterator
to build the resulting String, as well as to determine information about the resulting String.Each attribute key of the AttributedCharacterIterator will be of type
DateFormat.Field
, with the corresponding attribute value being the same as the attribute key.- Overrides:
formatToCharacterIterator
in classFormat
- Parameters:
obj
- The object to format- Returns:
- AttributedCharacterIterator describing the formatted value.
- Throws:
NullPointerException
- if obj is null.IllegalArgumentException
- if the Format cannot format the given object, or if the Format's pattern string is invalid.- Since:
- 1.4
-
parse
public Date parse(String text, ParsePosition pos)
Parses text from a string to produce aDate
.The method attempts to parse text starting at the index given by
pos
. If parsing succeeds, then the index ofpos
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 updatedpos
can be used to indicate the starting point for the next call to this method. If an error occurs, then the index ofpos
is not changed, the error index ofpos
is set to the index of the character where the error occurred, and null is returned.This parsing operation uses the
calendar
to produce aDate
. All of thecalendar
's date-time fields are cleared before parsing, and thecalendar
's default values of the date-time fields are used for any missing date-time information. For example, the year value of the parsedDate
is 1970 withGregorianCalendar
if no year value is given from the parsing operation. TheTimeZone
value may be overwritten, depending on the given pattern and the time zone value intext
. AnyTimeZone
value that has previously been set by a call tosetTimeZone
may need to be restored for further operations.- Specified by:
parse
in classDateFormat
- Parameters:
text
- AString
, part of which should be parsed.pos
- AParsePosition
object with index and error index information as described above.- Returns:
- A
Date
parsed from the string. In case of error, returns null. - Throws:
NullPointerException
- iftext
orpos
is null.
-
toPattern
public String toPattern()
Returns a pattern string describing this date format.- Returns:
- a pattern string describing this date format.
-
toLocalizedPattern
public String toLocalizedPattern()
Returns a localized pattern string describing this date format.- Returns:
- a localized pattern string describing this date format.
-
applyPattern
public void applyPattern(String pattern)
Applies the given pattern string to this date format.- Parameters:
pattern
- the new date and time pattern for this date format- Throws:
NullPointerException
- if the given pattern is nullIllegalArgumentException
- if the given pattern is invalid
-
applyLocalizedPattern
public void applyLocalizedPattern(String pattern)
Applies the given localized pattern string to this date format.- Parameters:
pattern
- a String to be mapped to the new date and time format pattern for this format- Throws:
NullPointerException
- if the given pattern is nullIllegalArgumentException
- if the given pattern is invalid
-
getDateFormatSymbols
public DateFormatSymbols getDateFormatSymbols()
Gets a copy of the date and time format symbols of this date format.- Returns:
- the date and time format symbols of this date format
- See Also:
setDateFormatSymbols(java.text.DateFormatSymbols)
-
setDateFormatSymbols
public void setDateFormatSymbols(DateFormatSymbols newFormatSymbols)
Sets the date and time format symbols of this date format.- Parameters:
newFormatSymbols
- the new date and time format symbols- Throws:
NullPointerException
- if the given newFormatSymbols is null- See Also:
getDateFormatSymbols()
-
clone
public Object clone()
Creates a copy of thisSimpleDateFormat
. This also clones the format's date format symbols.- Overrides:
clone
in classDateFormat
- Returns:
- a clone of this
SimpleDateFormat
- See Also:
Cloneable
-
hashCode
public int hashCode()
Returns the hash code value for thisSimpleDateFormat
object.- Overrides:
hashCode
in classDateFormat
- Returns:
- the hash code value for this
SimpleDateFormat
object. - See Also:
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
-
equals
public boolean equals(Object obj)
Compares the given object with thisSimpleDateFormat
for equality.- Overrides:
equals
in classDateFormat
- Parameters:
obj
- the reference object with which to compare.- Returns:
- true if the given object is equal to this
SimpleDateFormat
- See Also:
Object.hashCode()
,HashMap
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-
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