Package org.apache.logging.log4j.core.util.datetime

Class FastDateParser

  • All Implemented Interfaces:
    java.io.Serializable, DateParser
    public class FastDateParser
extends java.lang.Object
implements DateParser, java.io.Serializable

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

    To obtain a proxy to a FastDateParser, use FastDateFormat.getInstance(String, TimeZone, Locale) or another variation of the factory methods of FastDateFormat.

    Since FastDateParser is thread safe, you can use a static member instance:

    private static final DateParser DATE_PARSER = FastDateFormat.getInstance("yyyy-MM-dd");

    This class can be used as a direct replacement for SimpleDateFormat in most 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 has closed the bug/RFE.

    Only parsing is supported by this class, but all patterns are compatible with SimpleDateFormat.

    The class operates in lenient mode, so for example a time of 90 minutes is treated as 1 hour 30 minutes.

    Timing tests indicate this class is as about as fast as SimpleDateFormat in single thread applications and about 25% faster in multi-thread applications.

    Copied and modified from Apache Commons Lang.

    Since:
    Apache Commons Lang 3.2
    See Also:
    FastDatePrinter, Serialized Form

    • Constructor Detail

      • FastDateParser

        protected FastDateParser​(java.lang.String pattern,
                         java.util.TimeZone timeZone,
                         java.util.Locale locale)

        Constructs a new FastDateParser.

        Use FastDateFormat.getInstance(String, TimeZone, Locale) or another variation of the factory methods of FastDateFormat to get a cached FastDateParser instance.
        Parameters:
        pattern - non-null SimpleDateFormat compatible pattern
        timeZone - non-null time zone to use
        locale - non-null locale

      • FastDateParser

        protected FastDateParser​(java.lang.String pattern,
                         java.util.TimeZone timeZone,
                         java.util.Locale locale,
                         java.util.Date centuryStart)

        Constructs a new FastDateParser.

        Parameters:
        pattern - non-null SimpleDateFormat compatible pattern
        timeZone - non-null time zone to use
        locale - non-null locale
        centuryStart - The start of the century for 2 digit year parsing
        Since:
        3.5

    • Method Detail

      • init

        private void init​(java.util.Calendar definingCalendar)
        Initialize derived fields from defining fields. This is called from constructor and from readObject (de-serialization)
        Parameters:
        definingCalendar - the Calendar instance used to initialize this FastDateParser

      • isFormatLetter

        private static boolean isFormatLetter​(char c)

      • getPattern

        public java.lang.String getPattern()
        Description copied from interface: DateParser

        Gets the pattern used by this parser.

        Specified by:
        getPattern in interface DateParser
        Returns:
        the pattern, SimpleDateFormat compatible

      • getTimeZone

        public java.util.TimeZone getTimeZone()
        Description copied from interface: DateParser

        Gets the time zone used by this parser.

        The default TimeZone used to create a Date when the TimeZone is not specified by the format pattern.

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

      • getLocale

        public java.util.Locale getLocale()
        Description copied from interface: DateParser

        Gets the locale used by this parser.

        Specified by:
        getLocale in interface DateParser
        Returns:
        the locale

      • equals

        public boolean equals​(java.lang.Object obj)

        Compare another object for equality with this object.

        Overrides:
        equals in class java.lang.Object
        Parameters:
        obj - the object to compare to
        Returns:
        trueif equal to this instance

      • hashCode

        public int hashCode()

        Return a hash code compatible with equals.

        Overrides:
        hashCode in class java.lang.Object
        Returns:
        a hash code compatible with equals

      • toString

        public java.lang.String toString()

        Get a 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.

      • parseObject

        public java.lang.Object parseObject​(java.lang.String source)
                             throws java.text.ParseException
        Description copied from interface: DateParser
        Parses text from a string to produce a Date.
        Specified by:
        parseObject in interface DateParser
        Parameters:
        source - A String whose beginning should be parsed.
        Returns:
        a java.util.Date object
        Throws:
        java.text.ParseException - if the beginning of the specified string cannot be parsed.
        See Also:
        Format.parseObject(String)

      • parse

        public java.util.Date parse​(java.lang.String source)
                     throws java.text.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:
        java.text.ParseException - if the beginning of the specified string cannot be parsed.

      • parseObject

        public java.lang.Object parseObject​(java.lang.String source,
                                    java.text.ParsePosition pos)
        Description copied from interface: DateParser
        Parses a date/time string according to the given parse position.
        Specified by:
        parseObject in interface DateParser
        Parameters:
        source - A String whose beginning should be parsed.
        pos - the parse position
        Returns:
        a java.util.Date object
        See Also:
        DateFormat.parseObject(String, ParsePosition)

      • parse

        public java.util.Date parse​(java.lang.String source,
                            java.text.ParsePosition pos)
        This implementation updates the ParsePosition if the parse succeeds. However, it sets the error index to the position before the failed field unlike the method SimpleDateFormat.parse(String, ParsePosition) which sets the error index to after the failed field.

        To determine if the parse has succeeded, the caller must check if the current parse position given by ParsePosition.getIndex() has been updated. If the input buffer has been fully parsed, then the index will point to just after the end of the input buffer.

        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.
        See Also:
        DateParser.parse(java.lang.String, java.text.ParsePosition)

      • parse

        public boolean parse​(java.lang.String source,
                     java.text.ParsePosition pos,
                     java.util.Calendar calendar)
        Parse a formatted date string according to the format. Updates the Calendar with parsed fields. Upon success, the ParsePosition index is updated to indicate how much of the source text was consumed. Not all source text needs to be consumed. Upon parse failure, ParsePosition error index is updated to the offset of the source text which does not match the supplied format.
        Specified by:
        parse in interface DateParser
        Parameters:
        source - The text to parse.
        pos - On input, the position in the source to start parsing, on output, updated position.
        calendar - The calendar into which to set parsed fields.
        Returns:
        true, if source has been parsed (pos parsePosition is updated); otherwise false (and pos errorIndex is updated)
        Throws:
        java.lang.IllegalArgumentException - when Calendar has been set to be not lenient, and a parsed field is out of range.

      • simpleQuote

        private static java.lang.StringBuilder simpleQuote​(java.lang.StringBuilder sb,
                                                   java.lang.String value)

      • appendDisplayNames

        private static java.util.Map<java.lang.String,​java.lang.Integer> appendDisplayNames​(java.util.Calendar cal,
                                                                                          java.util.Locale locale,
                                                                                          int field,
                                                                                          java.lang.StringBuilder regex)
        Get the short and long values displayed for a field
        Parameters:
        cal - The calendar to obtain the short and long values
        locale - The locale of display names
        field - The field of interest
        regex - The regular expression to build
        Returns:
        The map of string display names to field values

      • adjustYear

        private int adjustYear​(int twoDigitYear)
        Adjust dates to be within appropriate century
        Parameters:
        twoDigitYear - The year to adjust
        Returns:
        A value between centuryStart(inclusive) to centuryStart+100(exclusive)

      • getStrategy

        private FastDateParser.Strategy getStrategy​(char f,
                                            int width,
                                            java.util.Calendar definingCalendar)
        Obtain a Strategy given a field from a SimpleDateFormat pattern
        Parameters:
        formatField - A sub-sequence of the SimpleDateFormat pattern
        definingCalendar - The calendar to obtain the short and long values
        Returns:
        The Strategy that will handle parsing for the field

      • getCache

        private static java.util.concurrent.ConcurrentMap<java.util.Locale,​FastDateParser.Strategy> getCache​(int field)
        Get a cache of Strategies for a particular field
        Parameters:
        field - The Calendar field
        Returns:
        a cache of Locale to Strategy

      • getLocaleSpecificStrategy

        private FastDateParser.Strategy getLocaleSpecificStrategy​(int field,
                                                          java.util.Calendar definingCalendar)
        Construct a Strategy that parses a Text field
        Parameters:
        field - The Calendar field
        definingCalendar - The calendar to obtain the short and long values
        Returns:
        a TextStrategy for the field and Locale