Class MailDateFormat

  • All Implemented Interfaces:
    Serializable, Cloneable

    public class MailDateFormat
    extends SimpleDateFormat
    Formats and parses date specification based on RFC 2822.

    This class does not support methods that influence the format. It always formats the date based on the specification below.

    3.3. Date and Time Specification

    Date and time occur in several header fields. This section specifies the syntax for a full date and time specification. Though folding white space is permitted throughout the date-time specification, it is RECOMMENDED that a single space be used in each place that FWS appears (whether it is required or optional); some older implementations may not interpret other occurrences of folding white space correctly.

     date-time       =       [ day-of-week "," ] date FWS time [CFWS]
    
     day-of-week     =       ([FWS] day-name) / obs-day-of-week
    
     day-name        =       "Mon" / "Tue" / "Wed" / "Thu" /
                             "Fri" / "Sat" / "Sun"
    
     date            =       day month year
    
     year            =       4*DIGIT / obs-year
    
     month           =       (FWS month-name FWS) / obs-month
    
     month-name      =       "Jan" / "Feb" / "Mar" / "Apr" /
                             "May" / "Jun" / "Jul" / "Aug" /
                             "Sep" / "Oct" / "Nov" / "Dec"
    
     day             =       ([FWS] 1*2DIGIT) / obs-day
    
     time            =       time-of-day FWS zone
    
     time-of-day     =       hour ":" minute [ ":" second ]
    
     hour            =       2DIGIT / obs-hour
    
     minute          =       2DIGIT / obs-minute
    
     second          =       2DIGIT / obs-second
    
     zone            =       (( "+" / "-" ) 4DIGIT) / obs-zone
     
    The day is the numeric day of the month. The year is any numeric year 1900 or later.

    The time-of-day specifies the number of hours, minutes, and optionally seconds since midnight of the date indicated.

    The date and time-of-day SHOULD express local time.

    The zone specifies the offset from Coordinated Universal Time (UTC, formerly referred to as "Greenwich Mean Time") that the date and time-of-day represent. The "+" or "-" indicates whether the time-of-day is ahead of (i.e., east of) or behind (i.e., west of) Universal Time. The first two digits indicate the number of hours difference from Universal Time, and the last two digits indicate the number of minutes difference from Universal Time. (Hence, +hhmm means +(hh * 60 + mm) minutes, and -hhmm means -(hh * 60 + mm) minutes). The form "+0000" SHOULD be used to indicate a time zone at Universal Time. Though "-0000" also indicates Universal Time, it is used to indicate that the time was generated on a system that may be in a local time zone other than Universal Time and therefore indicates that the date-time contains no information about the local time zone.

    A date-time specification MUST be semantically valid. That is, the day-of-the-week (if included) MUST be the day implied by the date, the numeric day-of-month MUST be between 1 and the number of days allowed for the specified month (in the specified year), the time-of-day MUST be in the range 00:00:00 through 23:59:60 (the number of seconds allowing for a leap second; see [STD12]), and the zone MUST be within the range -9959 through +9959.

    Synchronization

    Date formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.

    Since:
    JavaMail 1.2
    Author:
    Anthony Vanelverdinghe, Max Spivak
    See Also:
    Serialized Form
    • Constructor Detail

      • MailDateFormat

        public MailDateFormat()
        Create a new date format for the RFC2822 specification with lenient parsing.
    • Method Detail

      • format

        public StringBuffer format​(Date date,
                                   StringBuffer dateStrBuf,
                                   FieldPosition fieldPosition)
        Formats the given date in the format specified by RFC 2822 in the current TimeZone.
        Overrides:
        format in class SimpleDateFormat
        Parameters:
        date - the Date object
        dateStrBuf - the formatted string
        fieldPosition - the current field position
        Returns:
        StringBuffer the formatted String
        Since:
        JavaMail 1.2
      • parse

        public Date parse​(String text,
                          ParsePosition pos)
        Parses the given date in the format specified by RFC 2822.
        • With strict parsing, obs-* tokens are unsupported. Lenient parsing supports obs-year and obs-zone, with the exception of the 1-character military time zones.
        • The optional CFWS token at the end is not parsed.
        • RFC 2822 specifies that a zone of "-0000" indicates that the date-time contains no information about the local time zone. This class uses the UTC time zone in this case.
        Overrides:
        parse in class SimpleDateFormat
        Parameters:
        text - the formatted date to be parsed
        pos - the current parse position
        Returns:
        Date the parsed date. In case of error, returns null.
        Since:
        JavaMail 1.2
      • setCalendar

        public void setCalendar​(Calendar newCalendar)
        This method always throws an UnsupportedOperationException and should not be used because RFC 2822 mandates a specific calendar.
        Overrides:
        setCalendar in class DateFormat
        Throws:
        UnsupportedOperationException - if this method is invoked
      • setNumberFormat

        public void setNumberFormat​(NumberFormat newNumberFormat)
        This method always throws an UnsupportedOperationException and should not be used because RFC 2822 mandates a specific number format.
        Overrides:
        setNumberFormat in class DateFormat
        Throws:
        UnsupportedOperationException - if this method is invoked
      • applyPattern

        public void applyPattern​(String pattern)
        This method always throws an UnsupportedOperationException and should not be used because RFC 2822 mandates a specific pattern.
        Overrides:
        applyPattern in class SimpleDateFormat
        Throws:
        UnsupportedOperationException - if this method is invoked
        Since:
        JavaMail 1.6
      • get2DigitYearStart

        public Date get2DigitYearStart()
        This method always throws an UnsupportedOperationException and should not be used because RFC 2822 mandates another strategy for interpreting 2-digits years.
        Overrides:
        get2DigitYearStart in class SimpleDateFormat
        Returns:
        the start of the 100-year period into which two digit years are parsed
        Throws:
        UnsupportedOperationException - if this method is invoked
        Since:
        JavaMail 1.6
      • set2DigitYearStart

        public void set2DigitYearStart​(Date startDate)
        This method always throws an UnsupportedOperationException and should not be used because RFC 2822 mandates another strategy for interpreting 2-digits years.
        Overrides:
        set2DigitYearStart in class SimpleDateFormat
        Throws:
        UnsupportedOperationException - if this method is invoked
        Since:
        JavaMail 1.6