tig
Class Dates

java.lang.Object
  |
  +--tig.Dates

All Implemented Interfaces:

GeneralConstants

public abstract class Dates

extends java.lang.Object

implements GeneralConstants

Class containing utility static methods for date manipulation.
Dates are represented as an array of integers.
The internationalization of this class is hard coded (French and English are supported).
This class handles :

Date - julian day conversions (dateToJd(), jdToDate()).

Conversion between a String and a date (parseDate(), parseHour()).

Date formatting for display (formatDate(), formatHour()).

Field Summary

Fields inherited from interface tig.GeneralConstants

BLANK, FS, LS, NO_SPECIF, SPACE

Constructor Summary

Dates()

Method Summary

static double	calcDecDay(int d, int h, int m, int s) Returns the decimal part of the day.
static double	dateToJd(int[] date) Convenient method equivalent to dateToJd(int, int, int, int, int, int).
static double	dateToJd(int year, int month, int day, int hour, int minut, int sec) Calculates the number of julian days elapsed since jan 0.5 4712 BC, from a date and an hour.
static java.lang.String	formatDate(int[] date, java.lang.String lang) Formats a date into a displayable String.
static java.lang.String	formatDate(java.lang.String strDate, java.lang.String lang) Facility method, calling parseDate() and formatDate(int[], String).
static java.lang.String	formatHour(int[] hour, java.lang.String lang) Formats an hour into a displayable String.
static java.lang.String	formatHour(java.lang.String strHour, java.lang.String lang) Facility method, calling parseHour() and formatHour(int[], String).
static java.lang.String	formatHourDate(int[] hourDate, java.lang.String lang) Formats a date and an hour into a displayable String.
static java.lang.String	formatHourDate(java.lang.String strDate, java.lang.String strHour, java.lang.String lang) Facility method, calling parseHourDate() and formatHourDate(int[], String).
static boolean	isLeapYear(int y) Tests if y corresponds to a leap year.
static int[]	jdToDate(double jd) Computes the date and hour corresponding to a julian day (nb of days elapsed since jan 0.5 4712 BC).
static int[]	now() Returns an array containing date fields (in this order : year, month, day, hour, minuts, seconds) initialized to the current date.
static int[]	parseDate(java.lang.String strDate, java.lang.String lang) Transforms a date representated as a String to an array of integers containing the year, month, day.
static int[]	parseHour(java.lang.String strHour, java.lang.String lang) Transforms an hour representated as a String to an array of integers containing (in this order : hours, minutes, seconds.
static int[]	parseHourDate(java.lang.String strDate, java.lang.String strHour, java.lang.String lang) Transforms a date and an hour representated as Strings to an array of integers containing (in this order : years, months, days, hours, minutes, seconds.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Dates

public Dates()

Method Detail

dateToJd

public static double dateToJd(int[] date)

Convenient method equivalent to dateToJd(int, int, int, int, int, int).

dateToJd

public static double dateToJd(int year,
                              int month,
                              int day,
                              int hour,
                              int minut,
                              int sec)

Calculates the number of julian days elapsed since jan 0.5 4712 BC, from a date and an hour.

jdToDate

public static int[] jdToDate(double jd)

Computes the date and hour corresponding to a julian day (nb of days elapsed since jan 0.5 4712 BC).
From Jean Meeus' Astronomical Algorithms, 2nd edition, p 63.

Parameters:

jd - A positive number expressing the julian day.

Returns:

An array of six integers containing (in this order) : year, month, day, hour, minut, second.

Throws:

java.lang.RuntimeException - If parameter 'jd' < 0.

isLeapYear

public static boolean isLeapYear(int y)

Tests if y corresponds to a leap year.

Parameters:

y - positive number representing the year to test.

Returns:

true if y is positive and corresponds to a leap year.

now

public static int[] now()

Returns an array containing date fields (in this order : year, month, day, hour, minuts, seconds) initialized to the current date.

formatHourDate

public static java.lang.String formatHourDate(int[] hourDate,
                                              java.lang.String lang)

Formats a date and an hour into a displayable String.

Parameters:

hourDate - An array containing integers representing : year, month, day, hour, minut, second.

lang - language code, as specified by ISO-639 norm (supported languages : "en" and "fr").

Returns:

if lang='fr', format is "JJ/MM/AAAA HH:MM:SS" ;
if lang='en', format is "MM/JJ/AAAA HH:MM:SS".

Throws:

java.lang.IllegalArgumentException - if :

the length of 'hourDate' is different from 6 ;

the language is different from "en" or "fr".

formatDate

public static java.lang.String formatDate(int[] date,
                                          java.lang.String lang)

Formats a date into a displayable String.

Parameters:

date - An array containing 3 integers representing : year, month, day.

lang - language code, as specified by ISO-639 norm (supported languages : "en" and "fr").

Returns:

if lang='fr', format is "JJ/MM/AAAA" ;
if lang='en', format is "MM/JJ/AAAA".

Throws:

java.lang.IllegalArgumentException - if :

the length of 'date' is different from 3 ;

the language is different from "en" or "fr".

formatHour

public static java.lang.String formatHour(int[] hour,
                                          java.lang.String lang)

Formats an hour into a displayable String.

Parameters:

hour - An array containing 3 integers representing : hour, minut, second.

Returns:

A String formatted "HH:MM:SS", for lang='fr' or 'en';

Throws:

java.lang.IllegalArgumentException - if :

the length of 'hour' is different from 3 ;

the language is different from "en" or "fr".

formatHourDate

public static java.lang.String formatHourDate(java.lang.String strDate,
                                              java.lang.String strHour,
                                              java.lang.String lang)
                                       throws DateFormatException,
                                              HourFormatException

Facility method, calling parseHourDate() and formatHourDate(int[], String).

Throws:

DateFormatException - if parameter 'strDate' is not correct.

HourFormatException - if parameter 'strHour' is not correct.

formatDate

public static java.lang.String formatDate(java.lang.String strDate,
                                          java.lang.String lang)
                                   throws DateFormatException

Facility method, calling parseDate() and formatDate(int[], String).

Throws:

DateFormatException - if parameter 'strDate' is not correct.

formatHour

public static java.lang.String formatHour(java.lang.String strHour,
                                          java.lang.String lang)
                                   throws HourFormatException

Facility method, calling parseHour() and formatHour(int[], String).

Throws:

HourFormatException - if parameter 'strHour' is not correct.

parseHourDate

public static int[] parseHourDate(java.lang.String strDate,
                                  java.lang.String strHour,
                                  java.lang.String lang)
                           throws DateFormatException,
                                  HourFormatException,
                                  java.lang.IllegalArgumentException

Transforms a date and an hour representated as Strings to an array of integers containing (in this order : years, months, days, hours, minutes, seconds.
This method just calls parseHour(String, String) and parseDate(String, String). See their documentation for informations about parameter formats and exception thrown.

DateFormatException

HourFormatException

java.lang.IllegalArgumentException

parseDate

public static int[] parseDate(java.lang.String strDate,
                              java.lang.String lang)
                       throws DateFormatException,
                              java.lang.IllegalArgumentException

Transforms a date representated as a String to an array of integers containing the year, month, day.
How to express the date in 'strDate' :

Years, months and days must be separated by any non-numeric separator.

Years, months and days can be expressed with any number of digits ; years can be preceeded by a minus sign (if you want to express a negative year, first put a separator, and then the '-').

For English ('lang' = "en"), the order in 'strDate' must be months, days, years.

For French ('lang' = "fr"), the order in 'strDate' must be days, months, years.

Example of valid inputs and results.
French :

strDate	years	months	days
18/07/1998	18	7	1998
18.007:1998	18	7	1998
9-10 2000	9	10	2000
9 10 1	9	10	1
9 10 -16	9	10	-16
9-10--16	9	10	-16
9-10-16	9	10	16

English :

strDate	year	Month	Day
07/18/1998	18	7	1998
007:18.1998	18	7	1998
9-10 2000	10	9	2000
9 10 1	9	10	1
9 10 -16	10	9	-16
9-10--16	10	9	-16
9-10-16	10	9	16

Parameters:

strDate - A String containing the date, as specified above.

lang - language code, as specified by ISO-639 norm (supported languages : "en" and "fr").

Returns:

an array of integers in which are stored (in this order) years, months, days.

Throws:

java.lang.IllegalArgumentException - if parameter 'lang' is different from 'en' or 'fr'.

DateFormatException - if parameter 'strDate' is not correctly formatted.

parseHour

public static int[] parseHour(java.lang.String strHour,
                              java.lang.String lang)
                       throws HourFormatException,
                              java.lang.IllegalArgumentException

Transforms an hour representated as a String to an array of integers containing (in this order : hours, minutes, seconds.
Parameter 'lang' has no effect.
How to express the hour in 'strHour' :

Hours, minuts and seconds must be separated by any non-numeric character

Any non-numeric digit at the beginning or at the end of 'strHour" are skipped

If 'strHour' is empty, hours, minuts, seconds will be considered as equal to 0.

Seconds or {minutes and seconds} can be omitted, they will be considered as equal to 0.

Example of valid inputs and results.

strHour	hours	minuts	seconds
(empty string)	0	0	0
12	12	0	0
12h30m	12	30	0
-12:30:40s	12	30	40
000012h000030m00040	12	30	40

Parameters:

strHour - A String containing the hour, as specified above..

lang - language code, as specified by ISO-639 norm (supported languages : 'en' and 'fr').

Returns:

an array of integers in which are stored (in this order) hours, minuts, seconds.

Throws:

HourFormatException - if parameter 'strHour' is not correctly formatted.

java.lang.IllegalArgumentException - if parameter 'lang' is different from 'en' or 'fr'.

calcDecDay

public static double calcDecDay(int d,
                                int h,
                                int m,
                                int s)

Returns the decimal part of the day. The decimal part of the day expresses the fraction within the day.
ex : 23.75 means 23rd, 18h00m00s.