org.apache.commons.lang.time
Class FastDateFormat

java.lang.Object
  java.text.Format
      org.apache.commons.lang.time.FastDateFormat

All Implemented Interfaces:

Cloneable, Serializable

public class FastDateFormat

extends Format

FastDateFormat is a fast and thread-safe version of SimpleDateFormat.

This class can be used as a direct replacement to SimpleDateFormat in most formatting situations. This class is especially useful in multi-threaded server environments. SimpleDateFormat is not thread-safe in any JDK version, nor will it be as Sun have closed the bug/RFE.

Only formatting is supported, but all patterns are compatible with SimpleDateFormat (except time zones - see below).

Java 1.4 introduced a new pattern letter, 'Z', to represent time zones in RFC822 format (eg. +0800 or -1100). This pattern letter can be used here (on all JDK versions).

In addition, the pattern 'ZZ' has been made to represent ISO8601 full format time zones (eg. +08:00 or -11:00). This introduces a minor incompatability with Java 1.4, but at a gain of useful functionality.

Since:

2.0

Version:

$Id: FastDateFormat.java,v 1.15 2003/08/18 02:22:25 bayard Exp $

Author:

TeaTrove project, Brian S O'Neill, Sean Schofield, Gary Gregory, Stephen Colebourne

See Also:

Serialized Form

Nested Class Summary

Nested classes inherited from class java.text.Format

Format.Field

Field Summary

static int	FULL FULL locale dependent date or time style.
static int	LONG LONG locale dependent date or time style.
static int	MEDIUM MEDIUM locale dependent date or time style.
static int	SHORT SHORT locale dependent date or time style.

Constructor Summary

protected

FastDateFormat(String pattern, TimeZone timeZone, Locale locale) Constructs a new FastDateFormat.

Method Summary

protected StringBuffer	applyRules(Calendar calendar, StringBuffer buf) Performs the formatting by applying the rules to the specified calendar.
boolean	equals(Object obj) Compare two objects for equality.
String	format(Calendar calendar) Formats a Calendar object.
StringBuffer	format(Calendar calendar, StringBuffer buf) Formats a Calendar object into the supplied StringBuffer.
String	format(Date date) Formats a Date object.
StringBuffer	format(Date date, StringBuffer buf) Formats a Date object into the supplied StringBuffer.
StringBuffer	format(Object obj, StringBuffer toAppendTo, FieldPosition pos) Format either a Date or a Calendar object.
static FastDateFormat	getDateInstance(int style, TimeZone timeZone, Locale locale) Gets a date formatter instance using the specified style, time zone and locale.
static FastDateFormat	getDateTimeInstance(int dateStyle, int timeStyle, TimeZone timeZone, Locale locale) Gets a date/time formatter instance using the specified style, time zone and locale.
static FastDateFormat	getInstance() Gets a formatter instance using the default pattern in the default locale.
static FastDateFormat	getInstance(String pattern) Gets a formatter instance using the specified pattern in the default locale.
static FastDateFormat	getInstance(String pattern, Locale locale) Gets a formatter instance using the specified pattern and locale.
static FastDateFormat	getInstance(String pattern, TimeZone timeZone) Gets a formatter instance using the specified pattern and time zone.
static FastDateFormat	getInstance(String pattern, TimeZone timeZone, Locale locale) Gets a formatter instance using the specified pattern, time zone and locale.
Locale	getLocale() Gets the locale used by this formatter.
int	getMaxLengthEstimate() Gets an estimate for the maximum string length that the formatter will produce.
String	getPattern() Gets the pattern used by this formatter.
static FastDateFormat	getTimeInstance(int style, TimeZone timeZone, Locale locale) Gets a time formatter instance using the specified style, time zone and locale.
TimeZone	getTimeZone() Gets the time zone used by this formatter.
boolean	getTimeZoneOverridesCalendar() Returns true if the time zone of the calendar overrides the time zone of the formatter.
int	hashCode() A suitable hashcode.
protected void	init() Initialise the instance for first use.
Object	parseObject(String source, ParsePosition pos) Parsing not supported.
protected List	parsePattern() Returns a list of Rules given a pattern.
protected String	parseToken(String pattern, int[] indexRef) Performs the parsing of tokens.
protected org.apache.commons.lang.time.FastDateFormat.NumberRule	selectNumberRule(int field, int padding) Gets an appropriate rule for the padding required.
String	toString() Gets a debugging string version of this formatter.

Methods inherited from class java.text.Format

clone, format, formatToCharacterIterator, parseObject

Methods inherited from class java.lang.Object

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

Field Detail

FULL

public static final int FULL

FULL locale dependent date or time style.

See Also:

Constant Field Values

LONG

public static final int LONG

LONG locale dependent date or time style.

See Also:

Constant Field Values

MEDIUM

public static final int MEDIUM

MEDIUM locale dependent date or time style.

See Also:

Constant Field Values

SHORT

public static final int SHORT

SHORT locale dependent date or time style.

See Also:

Constant Field Values

Constructor Detail

FastDateFormat

protected FastDateFormat(String pattern,
                         TimeZone timeZone,
                         Locale locale)

Constructs a new FastDateFormat.

Parameters:

pattern - SimpleDateFormat compatible pattern

timeZone - time zone to use, null means use default for Date and value within for Calendar

locale - locale, null means use system default

Throws:

IllegalArgumentException - if pattern is invalid or null

Method Detail

getInstance

public static FastDateFormat getInstance()

Gets a formatter instance using the default pattern in the default locale.

Returns:

a date/time formatter

getInstance

public static FastDateFormat getInstance(String pattern)

Gets a formatter instance using the specified pattern in the default locale.

Parameters:

pattern - SimpleDateFormat compatible pattern

Returns:

a pattern based date/time formatter

Throws:

IllegalArgumentException - if pattern is invalid

getInstance

public static FastDateFormat getInstance(String pattern,
                                         TimeZone timeZone)

Gets a formatter instance using the specified pattern and time zone.

Parameters:

pattern - SimpleDateFormat compatible pattern

timeZone - optional time zone, overrides time zone of formatted date

Returns:

a pattern based date/time formatter

Throws:

IllegalArgumentException - if pattern is invalid

getInstance

public static FastDateFormat getInstance(String pattern,
                                         Locale locale)

Gets a formatter instance using the specified pattern and locale.

Parameters:

pattern - SimpleDateFormat compatible pattern

locale - optional locale, overrides system locale

Returns:

a pattern based date/time formatter

Throws:

IllegalArgumentException - if pattern is invalid

getInstance

public static FastDateFormat getInstance(String pattern,
                                         TimeZone timeZone,
                                         Locale locale)

Gets a formatter instance using the specified pattern, time zone and locale.

Parameters:

pattern - SimpleDateFormat compatible pattern

timeZone - optional time zone, overrides time zone of formatted date

locale - optional locale, overrides system locale

Returns:

a pattern based date/time formatter

Throws:

IllegalArgumentException - if pattern is invalid or null

getDateInstance

public static FastDateFormat getDateInstance(int style,
                                             TimeZone timeZone,
                                             Locale locale)

Gets a date formatter instance using the specified style, time zone and locale.

Parameters:

style - date style: FULL, LONG, MEDIUM, or SHORT

timeZone - optional time zone, overrides time zone of formatted date

locale - optional locale, overrides system locale

Returns:

a localized standard date formatter

Throws:

IllegalArgumentException - if the Locale has no date pattern defined

getTimeInstance

public static FastDateFormat getTimeInstance(int style,
                                             TimeZone timeZone,
                                             Locale locale)

Gets a time formatter instance using the specified style, time zone and locale.

Parameters:

style - time style: FULL, LONG, MEDIUM, or SHORT

timeZone - optional time zone, overrides time zone of formatted time

locale - optional locale, overrides system locale

Returns:

a localized standard time formatter

Throws:

IllegalArgumentException - if the Locale has no time pattern defined

getDateTimeInstance

public static FastDateFormat getDateTimeInstance(int dateStyle,
                                                 int timeStyle,
                                                 TimeZone timeZone,
                                                 Locale locale)

Gets a date/time formatter instance using the specified style, time zone and locale.

Parameters:

dateStyle - date style: FULL, LONG, MEDIUM, or SHORT

timeStyle - time style: FULL, LONG, MEDIUM, or SHORT

timeZone - optional time zone, overrides time zone of formatted date

locale - optional locale, overrides system locale

Returns:

a localized standard date/time formatter

Throws:

IllegalArgumentException - if the Locale has no date/time pattern defined

init

protected void init()

Initialise the instance for first use.

parsePattern

protected List parsePattern()

Returns a list of Rules given a pattern.

Returns:

a List of Rule objects

Throws:

IllegalArgumentException - if pattern is invalid

parseToken

protected String parseToken(String pattern,
                            int[] indexRef)

Performs the parsing of tokens.

Parameters:

pattern - the pattern

indexRef - index references

Returns:

parsed token

selectNumberRule

protected org.apache.commons.lang.time.FastDateFormat.NumberRule selectNumberRule(int field,
                                                                                  int padding)

Gets an appropriate rule for the padding required.

Parameters:

field - the field to get a rule for

padding - the padding required

Returns:

a new rule with the correct padding

format

public StringBuffer format(Object obj,
                           StringBuffer toAppendTo,
                           FieldPosition pos)

Format either a Date or a Calendar object.

Parameters:

obj - the object to format

toAppendTo - the buffer to append to

pos - the position - ignored

Returns:

the buffer passed in

format

public String format(Date date)

Formats a Date object.

Parameters:

date - the date to format

Returns:

the formatted string

format

public String format(Calendar calendar)

Formats a Calendar object.

Parameters:

calendar - the calendar to format

Returns:

the formatted string

format

public StringBuffer format(Date date,
                           StringBuffer buf)

Formats a Date object into the supplied StringBuffer.

Parameters:

date - the date to format

buf - the buffer to format into

Returns:

the specified string buffer

format

public StringBuffer format(Calendar calendar,
                           StringBuffer buf)

Formats a Calendar object into the supplied StringBuffer.

Parameters:

calendar - the calendar to format

buf - the buffer to format into

Returns:

the specified string buffer

applyRules

protected StringBuffer applyRules(Calendar calendar,
                                  StringBuffer buf)

Performs the formatting by applying the rules to the specified calendar.

Parameters:

calendar - the calendar to format

buf - the buffer to format into

Returns:

the specified string buffer

parseObject

public Object parseObject(String source,
                          ParsePosition pos)

Parsing not supported.

Parameters:

source - the string to parse

pos - the parsing position

Returns:

null as not supported

getPattern

public String getPattern()

Gets the pattern used by this formatter.

Returns:

the pattern, SimpleDateFormat compatible

getTimeZone

public TimeZone getTimeZone()

Gets the time zone used by this formatter.

This zone is always used for Date formatting. If a Calendar is passed in to be formatted, the time zone on that may be used depending on getTimeZoneOverridesCalendar().

Returns:

the time zone

getTimeZoneOverridesCalendar

public boolean getTimeZoneOverridesCalendar()

Returns true if the time zone of the calendar overrides the time zone of the formatter.

Returns:

true if time zone of formatter overridden for calendars

getLocale

public Locale getLocale()

Gets the locale used by this formatter.

Returns:

the locale

getMaxLengthEstimate

public int getMaxLengthEstimate()

Gets an estimate for the maximum string length that the formatter will produce.

The actual formatted length will almost always be less than or equal to this amount.

Returns:

the maximum formatted length

equals

public boolean equals(Object obj)

Compare two objects for equality.

Parameters:

obj - the object to compare to

Returns:

true if equal

hashCode

public int hashCode()

A suitable hashcode.

Returns:

a hashcode compatable with equals

toString

public String toString()

Gets a debugging string version of this formatter.

Returns:

a debugging string