|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object | +--superwaba.ext.xplat.util.datergf.DateTime
DateTime
implements a class consisting of a
Date
and
Time
.
This class has a Waba and a Java version, due to the following methods, which are implemented depending on the runtime environment:
Implemented? | |||
Java | Waba | Method name | Short Description |
yes | yes | public static void update(Object obj) | Updates a DateTime object,
a Date object or
a Time object to the
local time of the machine.
|
This version was created with Waba
(e.g. http://www.SuperWaba.org)
family of Java-compatible mobile systems (PDAs, Handies, etc.)
in mind. Hence this package does not use threads or exceptions.
The Waba version does not use the datatypes double and long.
(Though there are two methods in this class employing long,
meant for running under virtual machines offering that datatype:
toLong(int epoch)
and
valueOf(int epoch, long millis)
.)
The original Waba as well as many other Java VMs for small devices
do not support datatype long.
Some of the available operations are:
subtract(DateTime other)
),
unsigned
int
(yep!) on Waba (as well as creating them) which
allows one e.g. to use/create the Palm unsigned int
values directly
from Waba.
Examples:
DateTime dt1, dt2; dt1=new DateTime(2001,1,1,0,0,0); // yields: 2001-01-01 00:00:00 dt2=new DateTime(2005,12,31,11,59,59); // yields: 2005-12-31 11:59:59 float diff1=dt2.subtract(dt1); // yields: "1825.5" (1825 and 1/2 days) double diff2=dt2.subtractDouble(dt1); // yields: "1825.499988436699" // if running under Waba yields actual date and time: dt2.update(); diff1=dt2.subtract(dt1); // yields: number of days and time since the // beginning of the new millenium
Temporary dev-infos: version date remark 0.91.0 2003-04-07 - rgf; changed equals() to match the signature of Object.equals(); documents explicitly that the interface Comparable is implemented in this class 0.9.2 2001-03-21 - catering for changes in TimeRGF - deleted float/double subtract(), and their add()-counterparts - new subtract (and add()) working on a two-element int-array) under Waba exact to the millisecond (now using int only)! - corrected a bug with toLong() - added the Serializable interface; Date(), Time() have in addition readObject() and writeObject() implemented 2001-04-02 - introduced variant "JAVA" and "WABA"
Field Summary | |
Date |
date
Date field to store the date portion. |
Time |
time
Time field to store the time portion. |
Constructor Summary | |
DateTime()
Creates a DateTime object set to "0001-01-01 00:00:00.000". |
|
DateTime(Date date,
Time time)
Creates a DateTime object set to the arguments date and
time . |
|
DateTime(int year,
int month,
int day,
int hour,
int minute,
int second)
Creates a DateTime object set to the values from the arguments. |
|
DateTime(int year,
int month,
int day,
int hour,
int minute,
int second,
int millis)
Creates a DateTime object set to the values from the arguments. |
Method Summary | |
DateTime |
add(int days,
int millis)
Adds the number of days to the date field and the number of milliseconds to the time field of this DateTime object. |
DateTime |
assign(DateTime otherDateTime)
Assigns otherDateTime to this DateTime. |
int |
compareTo(Object otherDateTime)
|
Object |
copy()
Implements the "Clonable" interface. |
boolean |
equals(Object otherDateTime)
Implements the "Comparator.equals(Object obj)" interface. |
int[] |
subtract(DateTime other)
Subtracts a DateTime object from this one. |
int |
toInt(int epoch)
Renders the DateTime object into an int , encoded as seconds since/until
the given epoch. |
long |
toLong(int epoch)
Renders the DateTime object into a long, encoded as milliseconds since/until the given epoch. |
String |
toString()
Render the DateTime object to a string. |
DateTime |
update()
Updates the DateTime object to the actual local date and time of the machine. |
static DateTime |
valueOf(int epoch,
int unsigned_seconds)
Creates a DateTime from the unsigned int relative to the given epoch. |
static DateTime |
valueOf(int epoch,
long millis)
Creates a DateTime object from the number of milliseconds since/to the given epoch. |
Methods inherited from class java.lang.Object |
getClass,
hashCode,
notify,
wait,
wait |
Field Detail |
public Date date
public Time time
Constructor Detail |
public DateTime()
public DateTime(Date date, Time time)
date
and
time
.public DateTime(int year, int month, int day, int hour, int minute, int second)
year
- a value between 1 and 9999.month
- a value between 1 and 12.day
- a value between 1 and the maximum number of days of the appropriate month.hour
- a value between 0 and 23.minute
- a value between 0 and 59.second
- a value between 0 and 59.public DateTime(int year, int month, int day, int hour, int minute, int second, int millis)
year
- a value between 1 and 9999.month
- a value between 1 and 12.day
- a value between 1 and the maximum number of days of the appropriate month.hour
- a value between 0 and 23.minute
- a value between 0 and 59.second
- a value between 0 and 59.millis
- a value between 0 and 999.Method Detail |
public DateTime add(int days, int millis)
Works on any Java-VM, even ones
with no implementations of the long
or double
datatype, like some for
for PDAs (like the classic Waba); therefore there may be
rounding errors, if the integer part (representing whole days)
is too large.
// create a DateTime object with a // value of: "2010-01-12 14:05:47.123" DateTime dt=new DateTime(2010,01,12,14,05,47,123); dt.add(1, 64800000); // add 1 3/4 days == 1 day, 18 hours (= 64800000 millis) // "dt" now: "2010-01-14 08:05:47.123"
days
- number of days to add to DateTime.millis
- number of milliseconds to add to DateTime.public int[] subtract(DateTime other)
Works on any Java-VM, even ones
with no implementations of the double
datatype, like some for
for PDAs (like the classic Waba); therefore there may be
rounding errors, if the integer part (representing whole days)
is too large.
Example:
// create a DateTime object with a // value of: "2010-01-12 14:05:47" DateTime dt1=new DateTime(2010,01,12,14,05,47); // create a DateTime object with a // value of: "2010-01-14 08:05:47" DateTime dt2=new DateTime(2010,01,14,8,05,47); int [] diff=dt2.subtract(dt1); // yields: {1, 64800000};
other
- the DateTime object to subtract.int
array with two elements
public DateTime assign(DateTime otherDateTime)
public int compareTo(Object otherDateTime)
otherDateTime
- a DateTimepublic Object copy()
public boolean equals(Object otherDateTime)
otherDateTime
- a DateTimedate
and time
),
false else.public String toString()
public long toLong(int epoch)
Does not Work on
Java-VMs with no implementation of the long
datatype
(e.g. early versions of Waba for PDAs).
Remark: If your system is using seconds, then you need to
mulitply the second value by 1000
in order to arrive at the
needed millisecond value.
DateTime dt=new DateTime(2010,1,12, 14,5,47); // "dt" is now: "2010-01-12 14:05:47" long secs_long=dt.toLong(DTC.EPOCH_PALM); // "secs_long" is now: "3.346.149.947" seconds // since Date.EPOCH_PALM
epoch
- one of:
DTC.EPOCH_MACINTOSH
,
DTC.EPOCH_PALM
,
DTC.EPOCH_JAVA
,
DTC.EPOCH_DOS
,
DTC.EPOCH_WIN32
,
DTC.EPOCH_MJD
.
It is possible to use an integer encoded date (a positive number in
the form of: year*10000+month*100+day
) as the
epoch
. In such a case that date (starting at midnight)
is used as the epoch.
If an illegal epoch is given, the default epoch of
Date.getDefaultEpochDate()
is used.
public static DateTime valueOf(int epoch, long millis)
Does not Work on
Java-VMs with no implementation of the long
datatype
(e.g. early versions of Waba for PDAs).
Remark: If your system is using seconds, then you need to
mulitply the second value by 1000
in order to arrive at the
needed millisecond value.
// 3.346.149.947 seconds since Date.EPOCH_PALM, // which is exactly: "2010-01-12 14:05:47" long secs_long=3346149947l; DateTime dt=valueOf(DTC.EPOCH_PALM, secs_long); // "dt" is now: "2010-01-12 14:05:47"
epoch
- one of:
DTC.EPOCH_MACINTOSH
,
DTC.EPOCH_PALM
,
DTC.EPOCH_JAVA
,
DTC.EPOCH_DOS
,
DTC.EPOCH_WIN32
,
DTC.EPOCH_MJD
.
If an illegal epoch is given, the default epoch of
Date.getDefaultEpochDate()
is used.millis
- number of milliseconds since/to the epoch date (midnight).public int toInt(int epoch)
int
, encoded as seconds since/until
the given epoch. The 'epoch' is the basedate used to calculate the number of
seconds from/to this DateTime object.
Use this returned unsigned int
as a parameter for
valueOf(int unsigned_int, int epoch)
.
Remark: An int - if regarded as an unsigned int - can
store at most 49710 days and 23295 secs (or a value range between 0 and
4.294.967.295).
Therefore, one can only
cover the date/time-range between the epoch date (midnight) and
a little bit more than 135 years after it. E.g. for the
DTC.EPOCH_PALM
the maximum
date/time value storable is exactly: '2040-02-06 06:28:15' (an unsigned integer
with all bits set is represented as -1
if interpreted as a
signed integer).
This was written to support the Palm operating system which
uses an unsigned int representing the seconds elapsed since
its epoch (1904-01-01, midnight), cf.
DTC.EPOCH_PALM
.
// create "dt" and set it to: "2010-01-12 14:05:47" DateTime dt=new DateTime(2010,1,12, 14,5,47); int secs_int=dt.toInt(DTC.EPOCH_PALM); // "secs_int" is now: "-948.817.349", which is equivelant to // an unsigned int with a value of '3.346.149.947' // (seconds elapsed since Date.EPOCH_PALM)
epoch
- one of:
DTC.EPOCH_MACINTOSH
,
DTC.EPOCH_PALM
,
DTC.EPOCH_JAVA
,
DTC.EPOCH_DOS
,
DTC.EPOCH_WIN32
,
DTC.EPOCH_MJD
.
It is possible to use an integer encoded date (a positive number in
the form of: year*10000+month*100+day
) as the
epoch
. In such a case that date (starting at midnight)
is used as the epoch.
If an illegal epoch is given, the default epoch of
Date.getDefaultEpochDate()
is used.
int
representing the seconds to add
to the epoch in order
to arrive at this DateTime; if this DateTime is before
the epoch or after epoch+49710days+23295secs
then
0 is returned.public static DateTime valueOf(int epoch, int unsigned_seconds)
This was written to support the Palm operating system which
uses an unsigned int representing the seconds elapsed since
its epoch (1904-01-01, midnight), cf.
DTC.EPOCH_PALM
.
The algorithm uses (signed) int
only, such that this method can be used
on Java-bytecode systems, which do not support long (or double),
e.g. PDA's.
// The date and time "2010-01-12 14:05:47" lies // 3.346.149.947 seconds after Date.EPOCH_PALM; // if stored as an 'unsigned int' but referred to as // a 'signed int', one needs to use the value // '-948.817.349' in order to set the appropriate // bits. int secs_int=-948817349; DateTime dt=valueOf(DTC.EPOCH_PALM, secs_int); // "dt" is now: "2010-01-12 14:05:47"
epoch
- one of:
DTC.EPOCH_MACINTOSH
,
DTC.EPOCH_PALM
,
DTC.EPOCH_JAVA
,
DTC.EPOCH_DOS
,
DTC.EPOCH_WIN32
,
DTC.EPOCH_MJD
.unsigned_seconds
- an int
which gets interpreted as an
unsigned int
(cf.
toInt(int epoch)
).
It is possible to use an integer encoded date (a positive number in
the form of: year*10000+month*100+day
) as the
epoch
. In such a case that date (starting at midnight)
is used as the epoch.
If an illegal epoch is given, the default epoch of
Date.getDefaultEpochDate()
is used.
public DateTime update()
same
timestamp is used. Otherwise it is thinkable,
that while the Time object is updated the day rolls over and the update of the DateRGF
object reflects a different day (and vice versa).
Examples:
DateTime dt=new DateTime(); // yields: '0001-01-01 00:00:00.000' // if run on "2010-09-22" at "17:49:01.987", then dt.update(); // yields: '2010-09-22 17:49:01.987'
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |