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Java™ Platform Standard Ed. 6 |
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java.lang.Object java.text.Format java.text.DateFormat java.text.SimpleDateFormat
public class SimpleDateFormat
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
.
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):
Pattern letters are usually repeated, as their number determines the exact presentation:
Letter Date or Time Component Presentation Examples G
Era designator Text AD
y
Year Year 1996
;96
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 in week Text Tuesday
;Tue
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
Calendar
is the Gregorian
calendar, the following rules are applied.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
Character.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.
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.
RFC822TimeZone: Sign TwoDigitHours Minutes TwoDigitHours: Digit DigitTwoDigitHours must be between 00 and 23. Other definitions are as for general time zones.
For parsing, general time zones are also accepted.
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.
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
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.
Calendar
,
TimeZone
,
DateFormat
,
DateFormatSymbols
,
Serialized FormNested 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 | |
---|---|
SimpleDateFormat()
Constructs a SimpleDateFormat using the default pattern and
date format symbols for the default locale. |
|
SimpleDateFormat(String pattern)
Constructs a SimpleDateFormat using the given pattern and
the default date format symbols for the default locale. |
|
SimpleDateFormat(String pattern,
DateFormatSymbols formatSymbols)
Constructs a SimpleDateFormat using the given pattern and
date format symbols. |
|
SimpleDateFormat(String pattern,
Locale locale)
Constructs a SimpleDateFormat using the given pattern and
the default date format symbols for the given locale. |
Method Summary | |
---|---|
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 this SimpleDateFormat . |
boolean |
equals(Object obj)
Compares the given object with this SimpleDateFormat for
equality. |
StringBuffer |
format(Date date,
StringBuffer toAppendTo,
FieldPosition pos)
Formats the given Date into a date/time string and appends
the result to the given StringBuffer . |
AttributedCharacterIterator |
formatToCharacterIterator(Object obj)
Formats an Object producing an AttributedCharacterIterator . |
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 this SimpleDateFormat object. |
Date |
parse(String text,
ParsePosition pos)
Parses text from a string to produce a Date . |
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 |
Methods inherited from class java.lang.Object |
---|
finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
---|
public SimpleDateFormat()
SimpleDateFormat
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 the DateFormat
class.
public SimpleDateFormat(String pattern)
SimpleDateFormat
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 the DateFormat
class.
pattern
- the pattern describing the date and time format
NullPointerException
- if the given pattern is null
IllegalArgumentException
- if the given pattern is invalidpublic SimpleDateFormat(String pattern, Locale locale)
SimpleDateFormat
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 the DateFormat
class.
pattern
- the pattern describing the date and time formatlocale
- the locale whose date format symbols should be used
NullPointerException
- if the given pattern or locale is null
IllegalArgumentException
- if the given pattern is invalidpublic SimpleDateFormat(String pattern, DateFormatSymbols formatSymbols)
SimpleDateFormat
using the given pattern and
date format symbols.
pattern
- the pattern describing the date and time formatformatSymbols
- the date format symbols to be used for formatting
NullPointerException
- if the given pattern or formatSymbols is null
IllegalArgumentException
- if the given pattern is invalidMethod Detail |
---|
public void set2DigitYearStart(Date startDate)
startDate
- During parsing, two digit years will be placed in the range
startDate
to startDate + 100 years
.get2DigitYearStart()
public Date get2DigitYearStart()
set2DigitYearStart(java.util.Date)
public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition pos)
Date
into a date/time string and appends
the result to the given StringBuffer
.
format
in class DateFormat
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.
NullPointerException
- if the given date is nullpublic AttributedCharacterIterator formatToCharacterIterator(Object obj)
AttributedCharacterIterator
.
You can use the returned AttributedCharacterIterator
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.
formatToCharacterIterator
in class Format
obj
- The object to format
NullPointerException
- if obj is null.
IllegalArgumentException
- if the Format cannot format the
given object, or if the Format's pattern string is invalid.public Date parse(String text, 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.
parse
in class DateFormat
text
- 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 text
or pos
is null.DateFormat.setLenient(boolean)
public String toPattern()
public String toLocalizedPattern()
public void applyPattern(String pattern)
pattern
- the new date and time pattern for this date format
NullPointerException
- if the given pattern is null
IllegalArgumentException
- if the given pattern is invalidpublic void applyLocalizedPattern(String pattern)
pattern
- a String to be mapped to the new date and time format
pattern for this format
NullPointerException
- if the given pattern is null
IllegalArgumentException
- if the given pattern is invalidpublic DateFormatSymbols getDateFormatSymbols()
setDateFormatSymbols(java.text.DateFormatSymbols)
public void setDateFormatSymbols(DateFormatSymbols newFormatSymbols)
newFormatSymbols
- the new date and time format symbols
NullPointerException
- if the given newFormatSymbols is nullgetDateFormatSymbols()
public Object clone()
SimpleDateFormat
. This also
clones the format's date format symbols.
clone
in class DateFormat
SimpleDateFormat
Cloneable
public int hashCode()
SimpleDateFormat
object.
hashCode
in class DateFormat
SimpleDateFormat
object.Object.equals(java.lang.Object)
,
Hashtable
public boolean equals(Object obj)
SimpleDateFormat
for
equality.
equals
in class DateFormat
obj
- the reference object with which to compare.
SimpleDateFormat
Object.hashCode()
,
Hashtable
|
Java™ Platform Standard Ed. 6 |
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