org.apache.tools.ant.util

Class DateUtils


public final class DateUtils
extends java.lang.Object

Helper methods to deal with date/time formatting with a specific defined format (ISO8601) or a plurialization correct elapsed time in minutes and seconds.
Since:
Ant 1.5

Field Summary

static DateFormat
DATE_HEADER_FORMAT
Format used for SMTP (and probably other) Date headers.
static String
ISO8601_DATETIME_PATTERN
ISO8601-like pattern for date-time.
static String
ISO8601_DATE_PATTERN
ISO8601-like pattern for date.
static String
ISO8601_TIME_PATTERN
ISO8601-like pattern for time.

Method Summary

static String
format(Date date, String pattern)
Format a date/time into a specific pattern.
static String
format(long date, String pattern)
Format a date/time into a specific pattern.
static String
formatElapsedTime(long millis)
Format an elapsed time into a plurialization correct string.
static String
getDateForHeader()
Returns the current Date in a format suitable for a SMTP date header.
static int
getPhaseOfMoon(Calendar cal)
Calculate the phase of the moon for a given date.
static Date
parseIso8601Date(String datestr)
Parse a string as a date using the ISO8601_DATE format which is yyyy-MM-dd
static Date
parseIso8601DateTime(String datestr)
Parse a string as a datetime using the ISO8601_DATETIME format which is yyyy-MM-dd'T'HH:mm:ss
static Date
parseIso8601DateTimeOrDate(String datestr)
Parse a string as a date using the either the ISO8601_DATETIME or ISO8601_DATE formats.

Field Details

DATE_HEADER_FORMAT

public static final DateFormat DATE_HEADER_FORMAT
Format used for SMTP (and probably other) Date headers.

ISO8601_DATETIME_PATTERN

public static final String ISO8601_DATETIME_PATTERN
ISO8601-like pattern for date-time. It does not support timezone. yyyy-MM-ddTHH:mm:ss

ISO8601_DATE_PATTERN

public static final String ISO8601_DATE_PATTERN
ISO8601-like pattern for date. yyyy-MM-dd

ISO8601_TIME_PATTERN

public static final String ISO8601_TIME_PATTERN
ISO8601-like pattern for time. HH:mm:ss

Method Details

format

public static String format(Date date,
                            String pattern)
Format a date/time into a specific pattern.
Parameters:
date - the date to format expressed in milliseconds.
pattern - the pattern to use to format the date.
Returns:
the formatted date.

format

public static String format(long date,
                            String pattern)
Format a date/time into a specific pattern.
Parameters:
date - the date to format expressed in milliseconds.
pattern - the pattern to use to format the date.
Returns:
the formatted date.

formatElapsedTime

public static String formatElapsedTime(long millis)
Format an elapsed time into a plurialization correct string. It is limited only to report elapsed time in minutes and seconds and has the following behavior.
  • minutes are not displayed when 0. (ie: "45 seconds")
  • seconds are always displayed in plural form (ie "0 seconds" or "10 seconds") except for 1 (ie "1 second")
Parameters:
millis - the elapsed time to report in milliseconds.
Returns:
the formatted text in minutes/seconds.

getDateForHeader

public static String getDateForHeader()
Returns the current Date in a format suitable for a SMTP date header.
Returns:
the current date.
Since:
Ant 1.5.2

getPhaseOfMoon

public static int getPhaseOfMoon(Calendar cal)
Calculate the phase of the moon for a given date.

Code heavily influenced by hacklib.c in Nethack

The Algorithm:

 moon period = 29.53058 days ~= 30, year = 365.2422 days

 days moon phase advances on first day of year compared to preceding year
  = 365.2422 - 12*29.53058 ~= 11

 years in Metonic cycle (time until same phases fall on the same days of
  the month) = 18.6 ~= 19

 moon phase on first day of year (epact) ~= (11*(year%19) + 18) % 30
  (18 as initial condition for 1900)

 current phase in days = first day phase + days elapsed in year

 6 moons ~= 177 days
 177 ~= 8 reported phases * 22
 + 11/22 for rounding
 
Parameters:
cal - the calander.
Returns:
The phase of the moon as a number between 0 and 7 with 0 meaning new moon and 4 meaning full moon.
Since:
1.2, Ant 1.5

parseIso8601Date

public static Date parseIso8601Date(String datestr)
            throws ParseException
Parse a string as a date using the ISO8601_DATE format which is yyyy-MM-dd
Parameters:
datestr - string to be parsed
Returns:
a java.util.Date object as parsed by the format.
Since:
Ant 1.6

parseIso8601DateTime

public static Date parseIso8601DateTime(String datestr)
            throws ParseException
Parse a string as a datetime using the ISO8601_DATETIME format which is yyyy-MM-dd'T'HH:mm:ss
Parameters:
datestr - string to be parsed
Returns:
a java.util.Date object as parsed by the format.
Since:
Ant 1.6

parseIso8601DateTimeOrDate

public static Date parseIso8601DateTimeOrDate(String datestr)
            throws ParseException
Parse a string as a date using the either the ISO8601_DATETIME or ISO8601_DATE formats.
Parameters:
datestr - string to be parsed
Returns:
a java.util.Date object as parsed by the formats.
Since:
Ant 1.6