Package org.apache.commons.lang.time

Class FastDateFormat

java.lang.Object
java.text.Format
org.apache.commons.lang.time.FastDateFormat
All Implemented Interfaces:
Serializable, Cloneable
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 and some year patterns - 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 incompatibility with Java 1.4, but at a gain of useful functionality.

Javadoc cites for the year pattern: For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted as a number. Starting with Java 1.7 a pattern of 'Y' or 'YYY' will be formatted as '2003', while it was '03' in former Java versions. FastDateFormat implements the behavior of Java 7.

Since:
2.0
Version:
$Id: FastDateFormat.java 1057072 2011-01-10 01:55:57Z niallp $
See Also:

  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      Required for serialization support.
      See Also:

    • FULL

      public static final int FULL
      FULL locale dependent date or time style.
      See Also:

    • LONG

      public static final int LONG
      LONG locale dependent date or time style.
      See Also:

    • MEDIUM

      public static final int MEDIUM
      MEDIUM locale dependent date or time style.
      See Also:

    • SHORT

      public static final int SHORT
      SHORT locale dependent date or time style.
      See Also:

    • cDefaultPattern

      private static String cDefaultPattern

    • cInstanceCache

      private static final Map cInstanceCache

    • cDateInstanceCache

      private static final Map cDateInstanceCache

    • cTimeInstanceCache

      private static final Map cTimeInstanceCache

    • cDateTimeInstanceCache

      private static final Map cDateTimeInstanceCache

    • cTimeZoneDisplayCache

      private static final Map cTimeZoneDisplayCache

    • mPattern

      private final String mPattern
      The pattern.

    • mTimeZone

      private final TimeZone mTimeZone
      The time zone.

    • mTimeZoneForced

      private final boolean mTimeZoneForced
      Whether the time zone overrides any on Calendars.

    • mLocale

      private final Locale mLocale
      The locale.

    • mLocaleForced

      private final boolean mLocaleForced
      Whether the locale overrides the default.

    • mRules

      private transient FastDateFormat.Rule[] mRules
      The parsed rules.

    • mMaxLengthEstimate

      private transient int mMaxLengthEstimate
      The estimated maximum length.

  • Constructor Details

    • 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 Details

    • 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)

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

      Parameters:
      style - date style: FULL, LONG, MEDIUM, or SHORT
      Returns:
      a localized standard date formatter
      Throws:
      IllegalArgumentException - if the Locale has no date pattern defined
      Since:
      2.1

    • getDateInstance

      public static FastDateFormat getDateInstance(int style, Locale locale)

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

      Parameters:
      style - date style: FULL, LONG, MEDIUM, or SHORT
      locale - optional locale, overrides system locale
      Returns:
      a localized standard date formatter
      Throws:
      IllegalArgumentException - if the Locale has no date pattern defined
      Since:
      2.1

    • getDateInstance

      public static FastDateFormat getDateInstance(int style, TimeZone timeZone)

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

      Parameters:
      style - date style: FULL, LONG, MEDIUM, or SHORT
      timeZone - optional time zone, overrides time zone of formatted date
      Returns:
      a localized standard date formatter
      Throws:
      IllegalArgumentException - if the Locale has no date pattern defined
      Since:
      2.1

    • 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)

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

      Parameters:
      style - time style: FULL, LONG, MEDIUM, or SHORT
      Returns:
      a localized standard time formatter
      Throws:
      IllegalArgumentException - if the Locale has no time pattern defined
      Since:
      2.1

    • getTimeInstance

      public static FastDateFormat getTimeInstance(int style, Locale locale)

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

      Parameters:
      style - time style: FULL, LONG, MEDIUM, or SHORT
      locale - optional locale, overrides system locale
      Returns:
      a localized standard time formatter
      Throws:
      IllegalArgumentException - if the Locale has no time pattern defined
      Since:
      2.1

    • getTimeInstance

      public static FastDateFormat getTimeInstance(int style, TimeZone timeZone)

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

      Parameters:
      style - time style: FULL, LONG, MEDIUM, or SHORT
      timeZone - optional time zone, overrides time zone of formatted time
      Returns:
      a localized standard time formatter
      Throws:
      IllegalArgumentException - if the Locale has no time pattern defined
      Since:
      2.1

    • 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)

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

      Parameters:
      dateStyle - date style: FULL, LONG, MEDIUM, or SHORT
      timeStyle - time style: FULL, LONG, MEDIUM, or SHORT
      Returns:
      a localized standard date/time formatter
      Throws:
      IllegalArgumentException - if the Locale has no date/time pattern defined
      Since:
      2.1

    • getDateTimeInstance

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

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

      Parameters:
      dateStyle - date style: FULL, LONG, MEDIUM, or SHORT
      timeStyle - time style: FULL, LONG, MEDIUM, or SHORT
      locale - optional locale, overrides system locale
      Returns:
      a localized standard date/time formatter
      Throws:
      IllegalArgumentException - if the Locale has no date/time pattern defined
      Since:
      2.1

    • getDateTimeInstance

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

      Gets a date/time formatter instance using the specified style and time zone in the default 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
      Returns:
      a localized standard date/time formatter
      Throws:
      IllegalArgumentException - if the Locale has no date/time pattern defined
      Since:
      2.1

    • 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

    • getTimeZoneDisplay

      static String getTimeZoneDisplay(TimeZone tz, boolean daylight, int style, Locale locale)

      Gets the time zone display name, using a cache for performance.

      Parameters:
      tz - the zone to query
      daylight - true if daylight savings
      style - the style to use TimeZone.LONG or TimeZone.SHORT
      locale - the locale to use
      Returns:
      the textual name of the time zone

    • getDefaultPattern

      private static String getDefaultPattern()

      Gets the default pattern.

      Returns:
      the default pattern

    • init

      protected void init()

      Initializes 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 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)

      Formats a Date, Calendar or Long (milliseconds) object.

      Specified by:
      format in class Format
      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(long millis)

      Formats a millisecond long value.

      Parameters:
      millis - the millisecond value to format
      Returns:
      the formatted string
      Since:
      2.1

    • 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(long millis, StringBuffer buf)

      Formats a milliseond long value into the supplied StringBuffer.

      Parameters:
      millis - the millisecond value to format
      buf - the buffer to format into
      Returns:
      the specified string buffer
      Since:
      2.1

    • 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 is not supported.

      Specified by:
      parseObject in class Format
      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)

      Compares two objects for equality.

      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare to
      Returns:
      true if equal

    • hashCode

      public int hashCode()

      Returns a hashcode compatible with equals.

      Overrides:
      hashCode in class Object
      Returns:
      a hashcode compatible with equals

    • toString

      public String toString()

      Gets a debugging string version of this formatter.

      Overrides:
      toString in class Object
      Returns:
      a debugging string

    • readObject

      private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException
      Create the object after serialization. This implementation reinitializes the transient properties.
      Parameters:
      in - ObjectInputStream from which the object is being deserialized.
      Throws:
      IOException - if there is an IO issue.
      ClassNotFoundException - if a class cannot be found.