Package org.apache.log4j.pattern
Class CachedDateFormat
- java.lang.Object
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- java.text.Format
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- java.text.DateFormat
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- org.apache.log4j.pattern.CachedDateFormat
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- All Implemented Interfaces:
java.io.Serializable
,java.lang.Cloneable
public final class CachedDateFormat extends java.text.DateFormat
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:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static int
NO_MILLISECONDS
Constant used to represent that there was no change observed when changing the millisecond count.static int
UNRECOGNIZED_MILLISECONDS
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
Constructors Constructor Description CachedDateFormat(java.text.DateFormat dateFormat, int expiration)
Creates a new CachedDateFormat object.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static int
findMillisecondStart(long time, java.lang.String formatted, java.text.DateFormat formatter)
Finds start of millisecond field in formatted time.java.lang.StringBuffer
format(long now, java.lang.StringBuffer buf)
Formats a millisecond count into a date/time string.java.lang.StringBuffer
format(java.util.Date date, java.lang.StringBuffer sbuf, java.text.FieldPosition fieldPosition)
Formats a Date into a date/time string.static int
getMaximumCacheValidity(java.lang.String pattern)
Gets maximum cache validity for the specified SimpleDateTime conversion pattern.java.text.NumberFormat
getNumberFormat()
Gets number formatter.java.util.Date
parse(java.lang.String s, java.text.ParsePosition pos)
This method is delegated to the formatter which most likely returns null.void
setTimeZone(java.util.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
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Field Detail
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NO_MILLISECONDS
public static final int NO_MILLISECONDS
Constant used to represent that there was no change observed when changing the millisecond count.- See Also:
- Constant Field Values
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UNRECOGNIZED_MILLISECONDS
public static final int UNRECOGNIZED_MILLISECONDS
Constant used to represent that there was an observed change, but was an expected change.- See Also:
- Constant Field Values
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Constructor Detail
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CachedDateFormat
public CachedDateFormat(java.text.DateFormat dateFormat, int expiration)
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 Detail
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findMillisecondStart
public static int findMillisecondStart(long time, java.lang.String formatted, java.text.DateFormat formatter)
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
public java.lang.StringBuffer format(java.util.Date date, java.lang.StringBuffer sbuf, java.text.FieldPosition fieldPosition)
Formats a Date into a date/time string.- Specified by:
format
in classjava.text.DateFormat
- 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
public java.lang.StringBuffer format(long now, java.lang.StringBuffer buf)
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
public void setTimeZone(java.util.TimeZone timeZone)
Set timezone.Setting the timezone using getCalendar().setTimeZone() will likely cause caching to misbehave.
- Overrides:
setTimeZone
in classjava.text.DateFormat
- Parameters:
timeZone
- TimeZone new timezone
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parse
public java.util.Date parse(java.lang.String s, java.text.ParsePosition pos)
This method is delegated to the formatter which most likely returns null.- Specified by:
parse
in classjava.text.DateFormat
- Parameters:
s
- string representation of date.pos
- field position, unused.- Returns:
- parsed date, likely null.
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getNumberFormat
public java.text.NumberFormat getNumberFormat()
Gets number formatter.- Overrides:
getNumberFormat
in classjava.text.DateFormat
- Returns:
- NumberFormat number formatter
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getMaximumCacheValidity
public static int getMaximumCacheValidity(java.lang.String pattern)
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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