org.mpxj.common

Class LocalDateTimeHelper

java.lang.Object

org.mpxj.common.LocalDateTimeHelper

public final class LocalDateTimeHelper
extends Object

Common code for working with LocalDateTime instances.

Field Summary

Fields

Modifier and Type	Field and Description
static LocalDateTime	END_DATE_NA Date representing NA at the end of a date range: Friday December 31 23:59:00 2049.
static LocalDateTime	START_DATE_NA Date representing NA at the start of a date range: January 01 00:00:00 1984.

Constructor Summary

Constructors

Constructor and Description
LocalDateTimeHelper()

Method Summary

Modifier and Type	Method and Description
static int	compare(LocalDateTime d1, LocalDateTime d2) Compare two dates, handling null values.
static int	compare(LocalDateTime startDate, LocalDateTime endDate, LocalDateTime targetDate) This method compares a target date with a date range.
static LocalDateTime	getDayStartDate(LocalDateTime date) Returns a new Date instance whose value represents the start of the day (i.e.
static Duration	getVariance(ProjectCalendar calendar, LocalDateTime date1, LocalDateTime date2, TimeUnit format) This utility method calculates the difference in working time between two dates, given the context of a calendar.
static LocalDateTime	max(LocalDateTime d1, LocalDateTime d2) Returns the later of two dates, handling null values.
static LocalDateTime	min(LocalDateTime d1, LocalDateTime d2) Returns the earlier of two dates, handling null values.
static LocalDateTime	parseBest(DateTimeFormatter format, String value) Use the parseBest method of the formatter to retrieve a LocalDateTime instance handling the case where the formatter returns a LocalDate instance.

Methods inherited from class java.lang.Object

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

Field Detail

START_DATE_NA

public static final LocalDateTime START_DATE_NA

Date representing NA at the start of a date range: January 01 00:00:00 1984.

END_DATE_NA

public static final LocalDateTime END_DATE_NA

Date representing NA at the end of a date range: Friday December 31 23:59:00 2049. That's actually the value used by older versions of MS Project. The most recent version of MS Project uses Friday December 31 23:59:06 2049 (note the six extra seconds). The problem with using this value to represent NA at the end of a date range is it isn't interpreted correctly by older versions of MS Project. The compromise here is that we'll use the value recognised by older versions of MS Project, which will work as expected and display NA as the end date. For the current version of MS Project this will display a the end date as 2049, rather than NA, but this should still be interpreted correctly. TODO: consider making this behaviour configurable.

Constructor Detail

LocalDateTimeHelper

public LocalDateTimeHelper()

Method Detail

getDayStartDate

public static LocalDateTime getDayStartDate(LocalDateTime date)

Returns a new Date instance whose value represents the start of the day (i.e. the time of day is 00:00:00.000)

Parameters:

date - date to convert

Returns:

day start date

compare

public static int compare(LocalDateTime startDate,
                          LocalDateTime endDate,
                          LocalDateTime targetDate)

This method compares a target date with a date range. The method will return 0 if the date is within the range, less than zero if the date is before the range starts, and greater than zero if the date is after the range ends.

Parameters:

startDate - range start date

endDate - range end date

targetDate - target date in milliseconds

Returns:

comparison result

compare

public static int compare(LocalDateTime d1,
                          LocalDateTime d2)

Compare two dates, handling null values. TODO: correct the comparison order to align with Date.compareTo

Parameters:

d1 - Date instance

d2 - Date instance

Returns:

int comparison result

min

public static LocalDateTime min(LocalDateTime d1,
                                LocalDateTime d2)

Returns the earlier of two dates, handling null values. A non-null Date is always considered to be earlier than a null Date.

Parameters:

d1 - Date instance

d2 - Date instance

Returns:

Date earliest date

max

public static LocalDateTime max(LocalDateTime d1,
                                LocalDateTime d2)

Returns the later of two dates, handling null values. A non-null Date is always considered to be later than a null Date.

Parameters:

d1 - Date instance

d2 - Date instance

Returns:

Date latest date

parseBest

public static LocalDateTime parseBest(DateTimeFormatter format,
                                      String value)

Use the parseBest method of the formatter to retrieve a LocalDateTime instance handling the case where the formatter returns a LocalDate instance.

Parameters:

format - DateTimeFormatter instance

value - value to parse

Returns:

LocalDateTime instance

getVariance

public static Duration getVariance(ProjectCalendar calendar,
                                   LocalDateTime date1,
                                   LocalDateTime date2,
                                   TimeUnit format)

This utility method calculates the difference in working time between two dates, given the context of a calendar.

Parameters:

calendar - calendar

date1 - first date

date2 - second date

format - required format for the resulting duration

Returns:

difference in working time between the two dates