Class FastDateFormat

  • All Implemented Interfaces:
    Serializable, Cloneable, DateParser, DatePrinter

    public class FastDateFormat
    extends Format
    implements DateParser, DatePrinter
    FastDateFormat is a fast and thread-safe version of SimpleDateFormat.

    To obtain an instance of FastDateFormat, use one of the static factory methods: getInstance(String, TimeZone, Locale), getDateInstance(int, TimeZone, Locale), getTimeInstance(int, TimeZone, Locale), or getDateTimeInstance(int, int, TimeZone, Locale)

    Since FastDateFormat is thread safe, you can use a static member instance: private static final FastDateFormat DATE_FORMATTER = FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.SHORT);

    This class can be used as a direct replacement to SimpleDateFormat in most formatting and parsing 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.

    All patterns are compatible with SimpleDateFormat (except time zones and some year patterns - see below).

    Since 3.2, FastDateFormat supports parsing as well as printing.

    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 ISO 8601 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:
    $Id$
    See Also:
    Serialized Form
    • 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 - non-null time zone to use
        locale - non-null locale to use
        Throws:
        NullPointerException - if pattern, timeZone, or locale is null.
      • FastDateFormat

        protected FastDateFormat​(String pattern,
                                 TimeZone timeZone,
                                 Locale locale,
                                 Date centuryStart)
        Constructs a new FastDateFormat.
        Parameters:
        pattern - SimpleDateFormat compatible pattern
        timeZone - non-null time zone to use
        locale - non-null locale to use
        centuryStart - The start of the 100 year period to use as the "default century" for 2 digit year parsing. If centuryStart is null, defaults to now - 80 years
        Throws:
        NullPointerException - if pattern, timeZone, or locale is 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)
        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
      • format

        public StringBuffer format​(Object obj,
                                   StringBuffer toAppendTo,
                                   FieldPosition pos)
        Formats a Date, Calendar or Long (milliseconds) object.
        Specified by:
        format in interface DatePrinter
        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.
        Specified by:
        format in interface DatePrinter
        Parameters:
        millis - the millisecond value to format
        Returns:
        the formatted string
        Since:
        2.1
      • format

        public String format​(Date date)
        Formats a Date object using a GregorianCalendar.
        Specified by:
        format in interface DatePrinter
        Parameters:
        date - the date to format
        Returns:
        the formatted string
      • format

        public String format​(Calendar calendar)
        Formats a Calendar object.
        Specified by:
        format in interface DatePrinter
        Parameters:
        calendar - the calendar to format
        Returns:
        the formatted string
      • format

        public StringBuffer format​(long millis,
                                   StringBuffer buf)
        Formats a millisecond long value into the supplied StringBuffer.
        Specified by:
        format in interface DatePrinter
        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 using a GregorianCalendar.
        Specified by:
        format in interface DatePrinter
        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.
        Specified by:
        format in interface DatePrinter
        Parameters:
        calendar - the calendar to format
        buf - the buffer to format into
        Returns:
        the specified string buffer
      • parse

        public Date parse​(String source)
                   throws ParseException
        Description copied from interface: DateParser
        Equivalent to DateFormat.parse(String).

        See DateFormat.parse(String) for more information.

        Specified by:
        parse in interface DateParser
        Parameters:
        source - A String whose beginning should be parsed.
        Returns:
        A Date parsed from the string
        Throws:
        ParseException - if the beginning of the specified string cannot be parsed.
      • parse

        public Date parse​(String source,
                          ParsePosition pos)
        Description copied from interface: DateParser
        Equivalent to DateFormat.parse(String, ParsePosition).

        See DateFormat.parse(String, ParsePosition) for more information.

        Specified by:
        parse in interface DateParser
        Parameters:
        source - A String, part of which should be parsed.
        pos - A ParsePosition object with index and error index information as described above.
        Returns:
        A Date parsed from the string. In case of error, returns null.
      • getTimeZone

        public TimeZone getTimeZone()
        Gets the time zone used by this formatter.

        This zone is always used for Date formatting.

        Specified by:
        getTimeZone in interface DateParser
        Specified by:
        getTimeZone in interface DatePrinter
        Returns:
        the time zone
      • 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
      • 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