Class FastDateFormat

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable

    public class FastDateFormat
    extends java.text.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:
    Serialized Form
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected FastDateFormat​(java.lang.String pattern, java.util.TimeZone timeZone, java.util.Locale locale)
      Constructs a new FastDateFormat.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected java.lang.StringBuffer applyRules​(java.util.Calendar calendar, java.lang.StringBuffer buf)
      Performs the formatting by applying the rules to the specified calendar.
      boolean equals​(java.lang.Object obj)
      Compares two objects for equality.
      java.lang.String format​(long millis)
      Formats a millisecond long value.
      java.lang.StringBuffer format​(long millis, java.lang.StringBuffer buf)
      Formats a milliseond long value into the supplied StringBuffer.
      java.lang.StringBuffer format​(java.lang.Object obj, java.lang.StringBuffer toAppendTo, java.text.FieldPosition pos)
      Formats a Date, Calendar or Long (milliseconds) object.
      java.lang.String format​(java.util.Calendar calendar)
      Formats a Calendar object.
      java.lang.StringBuffer format​(java.util.Calendar calendar, java.lang.StringBuffer buf)
      Formats a Calendar object into the supplied StringBuffer.
      java.lang.String format​(java.util.Date date)
      Formats a Date object.
      java.lang.StringBuffer format​(java.util.Date date, java.lang.StringBuffer buf)
      Formats a Date object into the supplied StringBuffer.
      static FastDateFormat getDateInstance​(int style)
      Gets a date formatter instance using the specified style in the default time zone and locale.
      static FastDateFormat getDateInstance​(int style, java.util.Locale locale)
      Gets a date formatter instance using the specified style and locale in the default time zone.
      static FastDateFormat getDateInstance​(int style, java.util.TimeZone timeZone)
      Gets a date formatter instance using the specified style and time zone in the default locale.
      static FastDateFormat getDateInstance​(int style, java.util.TimeZone timeZone, java.util.Locale locale)
      Gets a date formatter instance using the specified style, time zone and locale.
      static FastDateFormat getDateTimeInstance​(int dateStyle, int timeStyle)
      Gets a date/time formatter instance using the specified style in the default time zone and locale.
      static FastDateFormat getDateTimeInstance​(int dateStyle, int timeStyle, java.util.Locale locale)
      Gets a date/time formatter instance using the specified style and locale in the default time zone.
      static FastDateFormat getDateTimeInstance​(int dateStyle, int timeStyle, java.util.TimeZone timeZone)
      Gets a date/time formatter instance using the specified style and time zone in the default locale.
      static FastDateFormat getDateTimeInstance​(int dateStyle, int timeStyle, java.util.TimeZone timeZone, java.util.Locale locale)
      Gets a date/time formatter instance using the specified style, time zone and locale.
      private static java.lang.String getDefaultPattern()
      Gets the default pattern.
      static FastDateFormat getInstance()
      Gets a formatter instance using the default pattern in the default locale.
      static FastDateFormat getInstance​(java.lang.String pattern)
      Gets a formatter instance using the specified pattern in the default locale.
      static FastDateFormat getInstance​(java.lang.String pattern, java.util.Locale locale)
      Gets a formatter instance using the specified pattern and locale.
      static FastDateFormat getInstance​(java.lang.String pattern, java.util.TimeZone timeZone)
      Gets a formatter instance using the specified pattern and time zone.
      static FastDateFormat getInstance​(java.lang.String pattern, java.util.TimeZone timeZone, java.util.Locale locale)
      Gets a formatter instance using the specified pattern, time zone and locale.
      java.util.Locale getLocale()
      Gets the locale used by this formatter.
      int getMaxLengthEstimate()
      Gets an estimate for the maximum string length that the formatter will produce.
      java.lang.String getPattern()
      Gets the pattern used by this formatter.
      static FastDateFormat getTimeInstance​(int style)
      Gets a time formatter instance using the specified style in the default time zone and locale.
      static FastDateFormat getTimeInstance​(int style, java.util.Locale locale)
      Gets a time formatter instance using the specified style and locale in the default time zone.
      static FastDateFormat getTimeInstance​(int style, java.util.TimeZone timeZone)
      Gets a time formatter instance using the specified style and time zone in the default locale.
      static FastDateFormat getTimeInstance​(int style, java.util.TimeZone timeZone, java.util.Locale locale)
      Gets a time formatter instance using the specified style, time zone and locale.
      java.util.TimeZone getTimeZone()
      Gets the time zone used by this formatter.
      (package private) static java.lang.String getTimeZoneDisplay​(java.util.TimeZone tz, boolean daylight, int style, java.util.Locale locale)
      Gets the time zone display name, using a cache for performance.
      boolean getTimeZoneOverridesCalendar()
      Returns true if the time zone of the calendar overrides the time zone of the formatter.
      int hashCode()
      Returns a hashcode compatible with equals.
      protected void init()
      Initializes the instance for first use.
      java.lang.Object parseObject​(java.lang.String source, java.text.ParsePosition pos)
      Parsing is not supported.
      protected java.util.List parsePattern()
      Returns a list of Rules given a pattern.
      protected java.lang.String parseToken​(java.lang.String pattern, int[] indexRef)
      Performs the parsing of tokens.
      private void readObject​(java.io.ObjectInputStream in)
      Create the object after serialization.
      protected FastDateFormat.NumberRule selectNumberRule​(int field, int padding)
      Gets an appropriate rule for the padding required.
      java.lang.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

      • serialVersionUID

        private static final long serialVersionUID
        Required for serialization support.
        See Also:
        Serializable, Constant Field Values
      • 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
      • cDefaultPattern

        private static java.lang.String cDefaultPattern
      • cInstanceCache

        private static final java.util.Map cInstanceCache
      • cDateInstanceCache

        private static final java.util.Map cDateInstanceCache
      • cTimeInstanceCache

        private static final java.util.Map cTimeInstanceCache
      • cDateTimeInstanceCache

        private static final java.util.Map cDateTimeInstanceCache
      • cTimeZoneDisplayCache

        private static final java.util.Map cTimeZoneDisplayCache
      • mPattern

        private final java.lang.String mPattern
        The pattern.
      • mTimeZone

        private final java.util.TimeZone mTimeZone
        The time zone.
      • mTimeZoneForced

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

        private final java.util.Locale mLocale
        The locale.
      • mLocaleForced

        private final boolean mLocaleForced
        Whether the locale overrides the default.
      • mMaxLengthEstimate

        private transient int mMaxLengthEstimate
        The estimated maximum length.
    • Constructor Detail

      • FastDateFormat

        protected FastDateFormat​(java.lang.String pattern,
                                 java.util.TimeZone timeZone,
                                 java.util.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:
        java.lang.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​(java.lang.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:
        java.lang.IllegalArgumentException - if pattern is invalid
      • getInstance

        public static FastDateFormat getInstance​(java.lang.String pattern,
                                                 java.util.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:
        java.lang.IllegalArgumentException - if pattern is invalid
      • getInstance

        public static FastDateFormat getInstance​(java.lang.String pattern,
                                                 java.util.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:
        java.lang.IllegalArgumentException - if pattern is invalid
      • getInstance

        public static FastDateFormat getInstance​(java.lang.String pattern,
                                                 java.util.TimeZone timeZone,
                                                 java.util.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:
        java.lang.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:
        java.lang.IllegalArgumentException - if the Locale has no date pattern defined
        Since:
        2.1
      • getDateInstance

        public static FastDateFormat getDateInstance​(int style,
                                                     java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no date pattern defined
        Since:
        2.1
      • getDateInstance

        public static FastDateFormat getDateInstance​(int style,
                                                     java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no date pattern defined
        Since:
        2.1
      • getDateInstance

        public static FastDateFormat getDateInstance​(int style,
                                                     java.util.TimeZone timeZone,
                                                     java.util.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:
        java.lang.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:
        java.lang.IllegalArgumentException - if the Locale has no time pattern defined
        Since:
        2.1
      • getTimeInstance

        public static FastDateFormat getTimeInstance​(int style,
                                                     java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no time pattern defined
        Since:
        2.1
      • getTimeInstance

        public static FastDateFormat getTimeInstance​(int style,
                                                     java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no time pattern defined
        Since:
        2.1
      • getTimeInstance

        public static FastDateFormat getTimeInstance​(int style,
                                                     java.util.TimeZone timeZone,
                                                     java.util.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:
        java.lang.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:
        java.lang.IllegalArgumentException - if the Locale has no date/time pattern defined
        Since:
        2.1
      • getDateTimeInstance

        public static FastDateFormat getDateTimeInstance​(int dateStyle,
                                                         int timeStyle,
                                                         java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no date/time pattern defined
        Since:
        2.1
      • getDateTimeInstance

        public static FastDateFormat getDateTimeInstance​(int dateStyle,
                                                         int timeStyle,
                                                         java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no date/time pattern defined
        Since:
        2.1
      • getDateTimeInstance

        public static FastDateFormat getDateTimeInstance​(int dateStyle,
                                                         int timeStyle,
                                                         java.util.TimeZone timeZone,
                                                         java.util.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:
        java.lang.IllegalArgumentException - if the Locale has no date/time pattern defined
      • getTimeZoneDisplay

        static java.lang.String getTimeZoneDisplay​(java.util.TimeZone tz,
                                                   boolean daylight,
                                                   int style,
                                                   java.util.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 java.lang.String getDefaultPattern()

        Gets the default pattern.

        Returns:
        the default pattern
      • init

        protected void init()

        Initializes the instance for first use.

      • parsePattern

        protected java.util.List parsePattern()

        Returns a list of Rules given a pattern.

        Returns:
        a List of Rule objects
        Throws:
        java.lang.IllegalArgumentException - if pattern is invalid
      • parseToken

        protected java.lang.String parseToken​(java.lang.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 java.lang.StringBuffer format​(java.lang.Object obj,
                                             java.lang.StringBuffer toAppendTo,
                                             java.text.FieldPosition pos)

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

        Specified by:
        format in class java.text.Format
        Parameters:
        obj - the object to format
        toAppendTo - the buffer to append to
        pos - the position - ignored
        Returns:
        the buffer passed in
      • format

        public java.lang.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 java.lang.String format​(java.util.Date date)

        Formats a Date object.

        Parameters:
        date - the date to format
        Returns:
        the formatted string
      • format

        public java.lang.String format​(java.util.Calendar calendar)

        Formats a Calendar object.

        Parameters:
        calendar - the calendar to format
        Returns:
        the formatted string
      • format

        public java.lang.StringBuffer format​(long millis,
                                             java.lang.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 java.lang.StringBuffer format​(java.util.Date date,
                                             java.lang.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 java.lang.StringBuffer format​(java.util.Calendar calendar,
                                             java.lang.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 java.lang.StringBuffer applyRules​(java.util.Calendar calendar,
                                                    java.lang.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 java.lang.Object parseObject​(java.lang.String source,
                                            java.text.ParsePosition pos)

        Parsing is not supported.

        Specified by:
        parseObject in class java.text.Format
        Parameters:
        source - the string to parse
        pos - the parsing position
        Returns:
        null as not supported
      • getPattern

        public java.lang.String getPattern()

        Gets the pattern used by this formatter.

        Returns:
        the pattern, SimpleDateFormat compatible
      • getTimeZone

        public java.util.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 java.util.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​(java.lang.Object obj)

        Compares two objects for equality.

        Overrides:
        equals in class java.lang.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 java.lang.Object
        Returns:
        a hashcode compatible with equals
      • toString

        public java.lang.String toString()

        Gets a debugging string version of this formatter.

        Overrides:
        toString in class java.lang.Object
        Returns:
        a debugging string
      • readObject

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