org.brains2b.util

Class DateHelper

java.lang.Object

org.brains2b.util.DateHelper

public class DateHelper
extends java.lang.Object

A function library giving some extra help dealing with dates.

Version:

$Revision: 1.18 $ $Date: 2014/07/10 08:28:12 $

Author:

dennis@brains2b.nl

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DateHelper.ThreadSafeDateFormat Thread save DateFormat

Field Summary

Fields

Modifier and Type	Field and Description
static DateHelper.ThreadSafeDateFormat	ISO_DATE a Thread safe implementation of DateFormat for an ISO date

Method Summary

Modifier and Type	Method and Description
static int	betweenDate(java.util.Calendar c1, java.util.Calendar c2, int field, boolean round) calculate the difference between two Calendars in intervals defined by field.
static int	betweenDate(java.util.Date d1, java.util.Date d2, int field, boolean round) calculate the difference between two Dates in intervals defined by field.
static java.lang.String	fromDate(java.util.Date dt) gets a date formatted as String with pattern "dd-MMM-yyyy"
static java.lang.String	isoFromDate(java.util.Date d) Writes a date to an ISO-string without time
static java.lang.String	isoFromDate(java.util.Date d, boolean includeTime) Writes a date to an ISO-string, either with or without time
static java.util.Date	isoToDate(java.lang.String s) Convert an ISO-date String into a Date
static java.util.Date	max(java.util.Date left, java.util.Date right) Return the last Date for two compared Dates
static java.util.Date	min(java.util.Date left, java.util.Date right) Return the first Date for two compared Dates
static java.util.Date	toDate(java.lang.String txt) returns a Date from a String representing a Date
static java.util.Date	toDate(java.lang.String txt, java.util.Locale locale) Attempts to convert a String to a Date in the most flexible manor using the specific locale to determine names and order

Methods inherited from class java.lang.Object

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

Field Detail

ISO_DATE

public static final DateHelper.ThreadSafeDateFormat ISO_DATE

a Thread safe implementation of DateFormat for an ISO date

Method Detail

fromDate

public static final java.lang.String fromDate(java.util.Date dt)

gets a date formatted as String with pattern "dd-MMM-yyyy"

Parameters:

dt - java.util.Date

Returns:

String the formatted date, or null if Date was not given.

toDate

public static final java.util.Date toDate(java.lang.String txt)
                                   throws java.lang.NumberFormatException

returns a Date from a String representing a Date

This toDate function is basically a rule based system recognizing a Date in the following patterns:

• a six digit String is interpreted as ddMMyy
• a String with a non character separator is interpreted as day-month-year
• day can be either 1 or 2 digits, with or without a leading 0
• month can be either 1 or 2 digits, with or without a leading 0, a String representing the long name or a short name of the month. The name of the month must be in the same language at which the VM it is operating is running in Locale.getDefault() is used to determine this.
• year can be 1 or 2 digits, with or without a leading 0. This is interpreted as a year without a century, so the current century is added. It can also be four digits and will then be intrepeted as year including a century.

Parameters:

txt - String that should be interpreted as Date

Returns:

Date, the result of transforming txt into a new Date

Throws:

java.lang.NumberFormatException - thrown if at an expected number was not found at the Expected position.

toDate

public static final java.util.Date toDate(java.lang.String txt,
                                          java.util.Locale locale)
                                   throws java.lang.NumberFormatException

Attempts to convert a String to a Date in the most flexible manor using the specific locale to determine names and order

Parameters:

txt - String

locale - Locale

Returns:

Date, the date converted from the String

Throws:

java.lang.NumberFormatException - thrown when String cannot be coverted to a date

isoFromDate

public static final java.lang.String isoFromDate(java.util.Date d,
                                                 boolean includeTime)

Writes a date to an ISO-string, either with or without time

Parameters:

d - Date to be converted

includeTime - boolean true is to include time

Returns:

ISO formatted String of the Date

isoFromDate

public static final java.lang.String isoFromDate(java.util.Date d)

Writes a date to an ISO-string without time

Parameters:

d - Date to be converted

Returns:

String, ISO formatted String of the Date

See Also:

isoFromDate(Date, boolean)

isoToDate

public static final java.util.Date isoToDate(java.lang.String s)

Convert an ISO-date String into a Date

Will work for ISO-date Strings with or without time

Parameters:

s - ISO formatted String

Returns:

Date, a Date object reflecting the ISO-date

betweenDate

public static final int betweenDate(java.util.Date d1,
                                    java.util.Date d2,
                                    int field,
                                    boolean round)

calculate the difference between two Dates in intervals defined by field.

The compare of the calendars follows normal conventions, so if c1 > c2 you will get a negative number. If rounding is on the level below is measured and normal rounding rules apply.

The field value should be one of Calendar.YEAR,Calendar.MONTH,Calendar.DATE

Parameters:

d1 - Date one (required)

d2 - Date two (required)

field - int, should be in (Calendar.YEAR|Calendar.MONTH|Calendar.DATE)

round - boolean, true if the should difference be rounded according to the normal rounding rules.False will floor the value

Returns:

int, the difference between the Dates in the defined measure

Since:

1.04.1

betweenDate

public static final int betweenDate(java.util.Calendar c1,
                                    java.util.Calendar c2,
                                    int field,
                                    boolean round)

calculate the difference between two Calendars in intervals defined by field.

The compare of the calendars follows normal conventions, so if c1 > c2 you will get a negative number. If rounding is on the level below is measured and normal rounding rules apply.

The field value should be one of Calendar.YEAR,Calendar.MONTH,Calendar.DATE

Parameters:

c1 - Calendar one (required)

c2 - Calendar two (required)

field - int, should be in (Calendar.YEAR|Calendar.MONTH|Calendar.DATE)

round - boolean, true if the should difference be rounded according to the normal rounding rules.False will floor the value

Returns:

int, the difference between the Calendars in the defined measure

Since:

1.04.1

min

public static final java.util.Date min(java.util.Date left,
                                       java.util.Date right)

Return the first Date for two compared Dates

If one of the dates is null the other one will be returned

Parameters:

left - Date

right - Date

Returns:

Date, the first of the two dates

max

public static final java.util.Date max(java.util.Date left,
                                       java.util.Date right)

Return the last Date for two compared Dates

If one of the dates is null the other one will be returned

Parameters:

left - Date

right - Date

Returns:

Date, the last of the two dates