Module jakarta.mail
Package jakarta.mail.internet

Class MailDateFormat

java.lang.Object
java.text.Format
java.text.DateFormat
java.text.SimpleDateFormat
jakarta.mail.internet.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
See Also:

  • Field Details

  • Constructor Details

    • MailDateFormat

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

  • Method Details

    • writeReplace

      private Object writeReplace() throws ObjectStreamException
      Allows to serialize instances such that they are deserializable with the previous implementation.
      Returns:
      the object to be serialized
      Throws:
      ObjectStreamException - never

    • readObject

      private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException
      Allows to deserialize instances that were serialized with the previous implementation.
      Parameters:
      in - the stream containing the serialized object
      Throws:
      IOException - on read failures
      ClassNotFoundException - never

    • clone

      public MailDateFormat clone()
      Overrides Cloneable.
      Overrides:
      clone in class SimpleDateFormat
      Returns:
      a clone of this instance
      Since:
      JavaMail 1.6

    • 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

    • applyLocalizedPattern

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

    • 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

    • superApplyPattern

      private void superApplyPattern(String pattern)
      This method allows serialization to change the pattern.

    • 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

    • setDateFormatSymbols

      public void setDateFormatSymbols(DateFormatSymbols newFormatSymbols)
      This method always throws an UnsupportedOperationException and should not be used because RFC 2822 mandates specific date format symbols.
      Overrides:
      setDateFormatSymbols in class SimpleDateFormat
      Throws:
      UnsupportedOperationException - if this method is invoked
      Since:
      JavaMail 1.6

    • toDate

      private Date toDate(int dayName, int day, int month, int year, int hour, int minute, int second, int zone)
      Returns the date, as specified by the parameters.
      Returns:
      the date, as specified by the parameters
      Throws:
      IllegalArgumentException - if this instance's Calendar is non-lenient and any of the parameters have invalid values, or if dayName is not consistent with day-month-year