Package org.apache.log4j.pattern
Class CachedDateFormat
java.lang.Object
java.text.Format
java.text.DateFormat
org.apache.log4j.pattern.CachedDateFormat
- All Implemented Interfaces:
Serializable
,Cloneable
CachedDateFormat optimizes the performance of a wrapped DateFormat. The
implementation is not thread-safe. If the millisecond pattern is not
recognized, the class will only use the cache if the same value is requested.
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class java.text.DateFormat
DateFormat.Field
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
Constant used to represent that there was no change observed when changing the millisecond count.static final int
Constant used to represent that there was an observed change, but was an expected change.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
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Constructor Summary
ConstructorsConstructorDescriptionCachedDateFormat
(DateFormat dateFormat, int expiration) Creates a new CachedDateFormat object. -
Method Summary
Modifier and TypeMethodDescriptionstatic int
findMillisecondStart
(long time, String formatted, DateFormat formatter) Finds start of millisecond field in formatted time.format
(long now, StringBuffer buf) Formats a millisecond count into a date/time string.format
(Date date, StringBuffer sbuf, FieldPosition fieldPosition) Formats a Date into a date/time string.static int
getMaximumCacheValidity
(String pattern) Gets maximum cache validity for the specified SimpleDateTime conversion pattern.Gets number formatter.parse
(String s, ParsePosition pos) This method is delegated to the formatter which most likely returns null.void
setTimeZone
(TimeZone timeZone) Set timezone.Methods inherited from class java.text.DateFormat
clone, equals, format, format, getAvailableLocales, getCalendar, getDateInstance, getDateInstance, getDateInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getInstance, getTimeInstance, getTimeInstance, getTimeInstance, getTimeZone, hashCode, isLenient, parse, parseObject, setCalendar, setLenient, setNumberFormat
Methods inherited from class java.text.Format
format, formatToCharacterIterator, parseObject
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Field Details
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NO_MILLISECONDS
public static final int NO_MILLISECONDSConstant used to represent that there was no change observed when changing the millisecond count.- See Also:
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UNRECOGNIZED_MILLISECONDS
public static final int UNRECOGNIZED_MILLISECONDSConstant used to represent that there was an observed change, but was an expected change.- See Also:
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Constructor Details
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CachedDateFormat
Creates a new CachedDateFormat object.- Parameters:
dateFormat
- Date format, may not be null.expiration
- maximum cached range in milliseconds. If the dateFormat is known to be incompatible with the caching algorithm, use a value of 0 to totally disable caching or 1 to only use cache for duplicate requests.
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Method Details
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findMillisecondStart
Finds start of millisecond field in formatted time.- Parameters:
time
- long time, must be integral number of secondsformatted
- String corresponding formatted stringformatter
- DateFormat date format- Returns:
- int position in string of first digit of milliseconds, -1 indicates no millisecond field, -2 indicates unrecognized field (likely RelativeTimeDateFormat)
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format
Formats a Date into a date/time string.- Specified by:
format
in classDateFormat
- Parameters:
date
- the date to format.sbuf
- the string buffer to write to.fieldPosition
- remains untouched.- Returns:
- the formatted time string.
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format
Formats a millisecond count into a date/time string.- Parameters:
now
- Number of milliseconds after midnight 1 Jan 1970 GMT.buf
- the string buffer to write to.- Returns:
- the formatted time string.
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setTimeZone
Set timezone. Setting the timezone using getCalendar().setTimeZone() will likely cause caching to misbehave.- Overrides:
setTimeZone
in classDateFormat
- Parameters:
timeZone
- TimeZone new timezone
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parse
This method is delegated to the formatter which most likely returns null.- Specified by:
parse
in classDateFormat
- Parameters:
s
- string representation of date.pos
- field position, unused.- Returns:
- parsed date, likely null.
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getNumberFormat
Gets number formatter.- Overrides:
getNumberFormat
in classDateFormat
- Returns:
- NumberFormat number formatter
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getMaximumCacheValidity
Gets maximum cache validity for the specified SimpleDateTime conversion pattern.- Parameters:
pattern
- conversion pattern, may not be null.- Returns:
- Duration in milliseconds from an integral second that the cache will return consistent results.
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