Package com.cedarsoftware.util

Class SafeSimpleDateFormat

java.lang.Object

java.text.Format

java.text.DateFormat

com.cedarsoftware.util.SafeSimpleDateFormat

All Implemented Interfaces:

Serializable, Cloneable

public class SafeSimpleDateFormat
extends DateFormat

Thread-safe wrapper for SimpleDateFormat with copy-on-write semantics.

Design goals:

• Source/binary compatible surface for existing users.
• Re-entrant and safe across threads (no shared mutable SDF instances).
• Performance: at most one SimpleDateFormat per thread per configuration.
• Mutators create a new immutable State; threads lazily rebuild their SDF (copy-on-write).

Hot path: no locks. Lookups happen in a per-thread LRU.

For legacy code that used SafeSimpleDateFormat.getDateFormat(pattern), this class still provides the static accessor, returning a thread-local SimpleDateFormat keyed only by pattern (same semantics as before).

Author:

John DeRegnaucourt ([email protected])
Copyright (c) Cedar Software LLC

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

License

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

See Also:

• 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	Description
SafeSimpleDateFormat(String format)

Method Summary

Modifier and Type	Method	Description
static void	clearStaticThreadLocalCache()	Clears the static accessor's per-thread cache.
void	clearThreadLocal()	Clears this instance’s cached formatter for the current thread.
static void	clearThreadLocalCache()	Clears all cached formatters for the current thread (instance-based cache).
boolean	equals(Object other)
StringBuffer	format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition)
static SimpleDateFormat	getDateFormat(String pattern)	Legacy static accessor preserved for compatibility.
int	hashCode()
Date	parse(String source, ParsePosition pos)
void	set2DigitYearStart(Date date)
void	setCalendar(Calendar cal)
void	setDateFormatSymbols(DateFormatSymbols symbols)
void	setLenient(boolean lenient)
void	setNumberFormat(NumberFormat format)
void	setTimeZone(TimeZone tz)
String	toString()

Methods inherited from class java.text.DateFormat

clone, format, format, getAvailableLocales, getCalendar, getDateInstance, getDateInstance, getDateInstance, getDateTimeInstance, getDateTimeInstance, getDateTimeInstance, getInstance, getNumberFormat, getTimeInstance, getTimeInstance, getTimeInstance, getTimeZone, isLenient, parse, parseObject

Methods inherited from class java.text.Format

format, formatToCharacterIterator, parseObject

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

SafeSimpleDateFormat

public SafeSimpleDateFormat(String format)

Method Details

getDateFormat

public static SimpleDateFormat getDateFormat(String pattern)

Legacy static accessor preserved for compatibility. Returns a per-thread cached SimpleDateFormat for the given pattern.

Note: Mutating the returned SimpleDateFormat (e.g., setTimeZone) will affect subsequent uses of this pattern in the same thread, just like the original implementation.

clearStaticThreadLocalCache

public static void clearStaticThreadLocalCache()

Clears the static accessor's per-thread cache.

format

public StringBuffer format(Date date,
 StringBuffer toAppendTo,
 FieldPosition fieldPosition)

Specified by:

format in class DateFormat

parse

public Date parse(String source,
 ParsePosition pos)

Specified by:

parse in class DateFormat

setTimeZone

public void setTimeZone(TimeZone tz)

Overrides:

setTimeZone in class DateFormat

setLenient

public void setLenient(boolean lenient)

Overrides:

setLenient in class DateFormat

setCalendar

public void setCalendar(Calendar cal)

Overrides:

setCalendar in class DateFormat

setNumberFormat

public void setNumberFormat(NumberFormat format)

Overrides:

setNumberFormat in class DateFormat

setDateFormatSymbols

public void setDateFormatSymbols(DateFormatSymbols symbols)

set2DigitYearStart

public void set2DigitYearStart(Date date)

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class DateFormat

hashCode

public int hashCode()

Overrides:

hashCode in class DateFormat

clearThreadLocalCache

public static void clearThreadLocalCache()

Clears all cached formatters for the current thread (instance-based cache).

clearThreadLocal

public void clearThreadLocal()

Clears this instance’s cached formatter for the current thread.