net.sourceforge.jtds.jdbc
Class DateTime

java.lang.Object
  net.sourceforge.jtds.jdbc.DateTime

public class DateTime

extends java.lang.Object

Encapsulates Sybase date/time values and provides conversions to and from Java classes.

Version:

$Id: DateTime.java,v 1.4.2.2 2009/08/20 19:44:04 ickzon Exp $

Author:

Mike Hutchinson

Field Summary

private static java.lang.ThreadLocal	calendar Per thread instance of Calendar used for conversions.
private int	date The date component of the server datetime value.
(package private) static int	DATE_NOT_USED Indicates date value not used.
private java.sql.Date	dateValue Cached value of the datetime as a java.sql.Date.
private short	day Unpacked day value.
private short	hour Unpacked hour value.
private short	millis Unpacked millisecond value.
private short	minute Unpacked minute value.
private short	month Unpacked month value.
private short	second Unpacked second value.
private java.lang.String	stringValue Cached value of the datetime as a String.
private int	time The time component of the server datetime value.
(package private) static int	TIME_NOT_USED Indicates time value not used.
private java.sql.Time	timeValue Cached value of the datetime as a java.sql.Time.
private java.sql.Timestamp	tsValue Cached value of the datetime as a java.sql.Timestamp.
private boolean	unpacked Indicates server datetime values have been unpacked.
private short	year Unpacked year value.

Constructor Summary

(package private)	DateTime(java.sql.Date d) Constructs a DateTime object from a java.sql.Date.
(package private)	DateTime(int date, int time) Constructs a DateTime object from the two integer components of a datetime.
(package private)	DateTime(short date, short time) Constructs a DateTime object from the two short components of a smalldatetime.
(package private)	DateTime(java.sql.Time t) Constructs a DateTime object from a java.sql.Time.
(package private)	DateTime(java.sql.Timestamp ts) Constructs a DateTime object from a java.sql.Timestamp.

Method Summary

(package private) int	getDate() Retrieves the date component of a datetime value.
(package private) int	getTime() Retrieves the time component of a datetime value.
void	packDate() Converts a calendar date into days since 1900 (Sybase epoch).
void	packTime() Converts separate time components into a datetime time value.
java.sql.Date	toDate() Retrieves the current datetime value as a Date.
java.lang.Object	toObject() Retrieves the current datetime value as a Time, Date or Timestamp.
java.lang.String	toString() Retrieves the current datetime value as a String.
java.sql.Time	toTime() Retrieves the current datetime value as a Time.
java.sql.Timestamp	toTimestamp() Retrieves the current datetime value as a Timestamp.
private void	unpackDateTime() Converts a Julian datetime from the Sybase epoch of 1900-01-01 to the equivalent unpacked year/month/day etc.

Methods inherited from class java.lang.Object

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

Field Detail

calendar

private static java.lang.ThreadLocal calendar

Per thread instance of Calendar used for conversions.

DATE_NOT_USED

static final int DATE_NOT_USED

Indicates date value not used.

See Also:

Constant Field Values

TIME_NOT_USED

static final int TIME_NOT_USED

Indicates time value not used.

See Also:

Constant Field Values

date

private int date

The date component of the server datetime value.

time

private int time

The time component of the server datetime value.

year

private short year

Unpacked year value.

month

private short month

Unpacked month value.

day

private short day

Unpacked day value.

hour

private short hour

Unpacked hour value.

minute

private short minute

Unpacked minute value.

second

private short second

Unpacked second value.

millis

private short millis

Unpacked millisecond value.

unpacked

private boolean unpacked

Indicates server datetime values have been unpacked.

stringValue

private java.lang.String stringValue

Cached value of the datetime as a String.

tsValue

private java.sql.Timestamp tsValue

Cached value of the datetime as a java.sql.Timestamp.

dateValue

private java.sql.Date dateValue

Cached value of the datetime as a java.sql.Date.

timeValue

private java.sql.Time timeValue

Cached value of the datetime as a java.sql.Time.

Constructor Detail

DateTime

DateTime(int date,
         int time)

Constructs a DateTime object from the two integer components of a datetime.

Parameters:

date - server date field

time - server time field

DateTime

DateTime(short date,
         short time)

Constructs a DateTime object from the two short components of a smalldatetime.

Parameters:

date - server date field

time - server time field

DateTime

DateTime(java.sql.Timestamp ts)
   throws java.sql.SQLException

Constructs a DateTime object from a java.sql.Timestamp.

Parameters:

ts - Timestamp object representing the datetime

Throws:

java.sql.SQLException - if the date is out of range

DateTime

DateTime(java.sql.Time t)
   throws java.sql.SQLException

Constructs a DateTime object from a java.sql.Time.

Parameters:

t - Time object representing the datetime

Throws:

java.sql.SQLException - if the time (date) is out of range

DateTime

DateTime(java.sql.Date d)
   throws java.sql.SQLException

Constructs a DateTime object from a java.sql.Date.

Parameters:

d - Date object representing the datetime

Throws:

java.sql.SQLException - if the Date is out of range

Method Detail

getDate

int getDate()

Retrieves the date component of a datetime value.

Returns:

the datetime date component as an int

getTime

int getTime()

Retrieves the time component of a datetime value.

Returns:

the datetime time component as an int

unpackDateTime

private void unpackDateTime()

Converts a Julian datetime from the Sybase epoch of 1900-01-01 to the equivalent unpacked year/month/day etc. Algorithm from Fliegel, H F and van Flandern, T C (1968). Communications of the ACM, Vol 11, No 10 (October, 1968).

           SUBROUTINE GDATE (JD, YEAR,MONTH,DAY)
     C
     C---COMPUTES THE GREGORIAN CALENDAR DATE (YEAR,MONTH,DAY)
     C   GIVEN THE JULIAN DATE (JD).
     C
           INTEGER JD,YEAR,MONTH,DAY,I,J,K
     C
           L= JD+68569
           N= 4*L/146097
           L= L-(146097*N+3)/4
           I= 4000*(L+1)/1461001
           L= L-1461*I/4+31
           J= 80*L/2447
           K= L-2447*J/80
           L= J/11
           J= J+2-12*L
           I= 100*(N-49)+I+L
     C
           YEAR= I
           MONTH= J
           DAY= K
     C
           RETURN
           END
 

packDate

public void packDate()
              throws java.sql.SQLException

Converts a calendar date into days since 1900 (Sybase epoch).

Algorithm from Fliegel, H F and van Flandern, T C (1968). Communications of the ACM, Vol 11, No 10 (October, 1968).

           INTEGER FUNCTION JD (YEAR,MONTH,DAY)
     C
     C---COMPUTES THE JULIAN DATE (JD) GIVEN A GREGORIAN CALENDAR
     C   DATE (YEAR,MONTH,DAY).
     C
           INTEGER YEAR,MONTH,DAY,I,J,K
     C
           I= YEAR
           J= MONTH
           K= DAY
     C
           JD= K-32075+1461*(I+4800+(J-14)/12)/4+367*(J-2-(J-14)/12*12)
          2    /12-3*((I+4900+(J-14)/12)/100)/4
     C
           RETURN
           END
 

Throws:

java.sql.SQLException - if the date is outside the accepted range, 1753-9999

packTime

public void packTime()

Converts separate time components into a datetime time value.

toTimestamp

public java.sql.Timestamp toTimestamp()

Retrieves the current datetime value as a Timestamp.

Returns:

the current datetime value as a java.sql.Timestamp

toDate

public java.sql.Date toDate()

Retrieves the current datetime value as a Date.

Returns:

the current datetime value as a java.sql.Date

toTime

public java.sql.Time toTime()

Retrieves the current datetime value as a Time.

Returns:

the current datetime value as a java.sql.Time

toObject

public java.lang.Object toObject()

Retrieves the current datetime value as a Time, Date or Timestamp.

Returns:

the current datetime value as an java.lang.Object

toString

public java.lang.String toString()

Retrieves the current datetime value as a String.

Returns:

the current datetime value as a String