visad
Class DateTime

java.lang.Object
  visad.ThingImpl
      visad.DataImpl
          visad.Scalar
              visad.Real
                  visad.DateTime

All Implemented Interfaces:

Serializable, Cloneable, Comparable, Data, RealIface, ScalarIface, Thing

public class DateTime
extends Real

DateTime is a class of objects for holding date and time information. DateTime objects are immutable.

Internally, the object uses seconds since the epoch (1970-01-01 00:00:00Z) as the temporal reference.

See Also:

System.currentTimeMillis(), Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class visad.DataImpl

DataImpl.Syncher

Field Summary

static String	DEFAULT_TIME_FORMAT Default Time Format Pattern (yyyy-MM-dd HH:mm:ss)
static TimeZone	DEFAULT_TIMEZONE Default Time Zone (GMT)

Fields inherited from interface visad.Data

ABS, ACOS, ACOS_DEGREES, ADD, ASIN, ASIN_DEGREES, ATAN, ATAN_DEGREES, ATAN2, ATAN2_DEGREES, CEIL, COS, COS_DEGREES, DEGREES_TO_RADIANS, DEPENDENT, DIVIDE, EXP, FLOOR, INDEPENDENT, INV_ATAN2, INV_ATAN2_DEGREES, INV_DIVIDE, INV_POW, INV_REMAINDER, INV_SUBTRACT, LOG, MAX, MIN, MULTIPLY, NEAREST_NEIGHBOR, NEGATE, NO_ERRORS, NOP, POW, RADIANS_TO_DEGREES, REMAINDER, RINT, ROUND, SIN, SIN_DEGREES, SQRT, SUBTRACT, TAN, TAN_DEGREES, WEIGHTED_AVERAGE

Constructor Summary

DateTime()
Construct a DateTime object and initialize it to the current date/time.

DateTime(Date date)
Construct a DateTime object and initialize it with a Java date.

DateTime(double seconds)
Construct a DateTime object and initialize it with the seconds since January 1, 1970 00:00:00Z.

DateTime(double timeValue, Unit timeUnits)
Construct a DateTime object from a tim value and a Unit

DateTime(int year, int day, double seconds)
Construct a DateTime object initialized with a year, day of the year, and seconds in the day.

DateTime(Real real)
Construct a DateTime object and initialize it using a VisAD Real.

Method Summary

int	compareTo(Object oo) Implement Comparable interface
static DateTime	createDateTime(String dateString) Create a DateTime object from a string specification
static DateTime	createDateTime(String dateString, String format) Create a DateTime object from a string specification using the supplied pattern and default timezone.
static DateTime	createDateTime(String dateString, String format, TimeZone timezone) Create a DateTime object from a string specification using the supplied pattern and timezone.
String	dateString() Return a string representing the "date" portion of this DateTime
String	formattedString(String pattern, TimeZone timezone) Return a string representation of this DateTime from a user specified format.
static Real	fromYearDaySeconds(int year, int day, double seconds) Return a Real object whose value is the seconds since the Epoch initialized with a year, day of the year, and seconds in the day.
static String	getFormatPattern() Return the format pattern used in the output of the toString() method.
static TimeZone	getFormatTimeZone() Return the TimeZone used in the output of the toString() method.
Real	getReal() Get a Real representing the number of seconds since * the epoch.
static void	main(String[] args) run 'java visad.DateTime' to test the DateTime class
static Gridded1DDoubleSet	makeTimeSet(DateTime[] times) Create a Gridded1DDoubleSet from an array of DateTimes
static Gridded1DDoubleSet	makeTimeSet(double[] times) Create a Gridded1DDoubleSet from an array of doubles of seconds since the epoch.
static void	resetFormat() Reset the format of the output of the toString() method to the default - yyyy-MM-dd HH:mm:ssZ (ex: 1999-05-04 15:27:08Z) and the TimeZone to UTC.
static void	setDateFormatClass(Class dateFormatClass) You can override the DateFormat by specifying a class.
static void	setFormatPattern(String pattern) Set the format of the output of the toString() method.
static void	setFormatTimeZone(TimeZone tz) Set the TimeZone of the output of the toString() method.
static DateTime[]	timeSetToArray(Gridded1DSet timeSet) Create an array of DateTimes from a Gridded1DSet of times.
String	timeString() Return a string representing the "time" portion of this DateTime
String	toString() Return a string representation of this DateTime.
String	toValueString() Gets a string that represents just the value portion of this DateTime -- but with full semantics.

Methods inherited from class visad.Real

__eq__, __eq__, __ge__, __ge__, __gt__, __gt__, __le__, __le__, __lt__, __lt__, __ne__, __ne__, adjustSamplingError, binary, cloneButUnit, cloneButValue, computeRanges, equals, getError, getUnit, getValue, getValue, hashCode, isMissing, longString, unary

Methods inherited from class visad.Scalar

addReference, clone, removeReference

Methods inherited from class visad.DataImpl

__add__, __add__, __div__, __div__, __mod__, __mod__, __mul__, __mul__, __neg__, __pow__, __pow__, __radd__, __rdiv__, __rmod__, __rmul__, __rpow__, __rsub__, __sub__, __sub__, abs, abs, acos, acos, acosDegrees, acosDegrees, add, add, asin, asin, asinDegrees, asinDegrees, atan, atan, atan2, atan2, atan2Degrees, atan2Degrees, atanDegrees, atanDegrees, binary, ceil, ceil, changeMathType, computeRanges, computeRanges, cos, cos, cosDegrees, cosDegrees, dataClone, divide, divide, exp, exp, floor, floor, getType, local, log, log, longString, max, max, min, min, multiply, multiply, negate, negate, notifyReferences, pow, pow, remainder, remainder, rint, rint, round, round, sin, sin, sinDegrees, sinDegrees, sqrt, sqrt, subtract, subtract, tan, tan, tanDegrees, tanDegrees, unary

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface visad.Data

abs, abs, acos, acos, acosDegrees, acosDegrees, add, add, asin, asin, asinDegrees, asinDegrees, atan, atan, atan2, atan2, atan2Degrees, atan2Degrees, atanDegrees, atanDegrees, binary, ceil, ceil, changeMathType, computeRanges, computeRanges, cos, cos, cosDegrees, cosDegrees, dataClone, divide, divide, exp, exp, floor, floor, getType, local, log, log, longString, max, max, min, min, multiply, multiply, negate, negate, pow, pow, remainder, remainder, rint, rint, round, round, sin, sin, sinDegrees, sinDegrees, sqrt, sqrt, subtract, subtract, tan, tan, tanDegrees, tanDegrees, unary

Methods inherited from interface visad.Thing

addReference, removeReference

Field Detail

DEFAULT_TIME_FORMAT

public static final String DEFAULT_TIME_FORMAT

Default Time Format Pattern (yyyy-MM-dd HH:mm:ss)

See Also:

Constant Field Values

DEFAULT_TIMEZONE

public static final TimeZone DEFAULT_TIMEZONE

Default Time Zone (GMT)

Constructor Detail

DateTime

public DateTime(Real real)
         throws VisADException

Construct a DateTime object and initialize it using a VisAD Real. Unless the units of the Real specify otherwise, the Real's value is assumed to be seconds since the Epoch (i.e. 1970-01-01 00:00:00Z).

Parameters:

real - Real value in a temporal unit.

Throws:

VisADException - unit conversion problem

DateTime

public DateTime(double seconds)
         throws VisADException

Construct a DateTime object and initialize it with the seconds since January 1, 1970 00:00:00Z.

Parameters:

seconds - number of seconds since 1970-01-01 00:00:00Z.

Throws:

VisADException - unit conversion problem

DateTime

public DateTime(double timeValue,
                Unit timeUnits)
         throws VisADException

Construct a DateTime object from a tim value and a Unit

Parameters:

timeValue - value of time in timeUnits

timeUnits - units of value

Throws:

VisADException

DateTime

public DateTime(Date date)
         throws VisADException

Construct a DateTime object and initialize it with a Java date.

Parameters:

date - date object

Throws:

VisADException - unit conversion problem

DateTime

public DateTime()
         throws VisADException

Construct a DateTime object and initialize it to the current date/time.

Throws:

VisADException - unit conversion problem

DateTime

public DateTime(int year,
                int day,
                double seconds)
         throws VisADException

Construct a DateTime object initialized with a year, day of the year, and seconds in the day.

Parameters:

year - year - use negative year to indicated BC

day - day of the year

seconds - seconds in the day

Throws:

VisADException - invalid day or seconds. Days must be greater than zero and seconds must be greater than zero and less than or equal to the seconds in a day.

Method Detail

fromYearDaySeconds

public static Real fromYearDaySeconds(int year,
                                      int day,
                                      double seconds)
                               throws VisADException

Return a Real object whose value is the seconds since the Epoch initialized with a year, day of the year, and seconds in the day.

Parameters:

year - year - use negative year to indicated BC

day - day of the year

seconds - seconds in the day

Throws:

VisADException - invalid day or seconds. Days must be greater than zero and seconds must be greater than zero and less than or equal to the seconds in a day.

getReal

public Real getReal()

Get a Real representing the number of seconds since * the epoch.

Returns:

this object

toString

public String toString()

Return a string representation of this DateTime. Unless the setFormatPattern() and/or setTimeZone() methods were used, the default it the ISO 8601 complete date plus hours, minutes and seconds and a time zone of UTC. See http://www.w3.org/TR/NOTE-datetime

Specified by:

toString in interface RealIface

Overrides:

toString in class Real

Returns:

String representing the date/time. Default is yyyy-MM-dd HH:mm:ssZ (ex: 1999-05-04 15:27:08Z)

See Also:

setFormatPattern(java.lang.String), setFormatTimeZone(java.util.TimeZone)

toValueString

public String toValueString()

Gets a string that represents just the value portion of this DateTime -- but with full semantics.

Specified by:

toValueString in interface RealIface

Overrides:

toValueString in class Real

Returns:

String representing the date/time in the form yyyy-MM-dd HH:mm:ssZ (ex: 1999-05-04 15:27:08Z)

formattedString

public String formattedString(String pattern,
                              TimeZone timezone)

Return a string representation of this DateTime from a user specified format. The pattern uses the time format syntax of java.text.SimpleDateFormat and the time zone is any of the valid java.util.TimeZone values.

Parameters:

pattern - time format string

timezone - time zone to use

Returns:

String representing the date/time in the form specified by the pattern.

See Also:

SimpleDateFormat, TimeZone

dateString

public String dateString()

Return a string representing the "date" portion of this DateTime

Returns:

String representing the date (UTC) in the form yyyy-MM-dd (ex: 1999-05-04).

timeString

public String timeString()

Return a string representing the "time" portion of this DateTime

Returns:

String representing the time (UTC) in the form HH:mm:ssZ (ex: 15:27:08Z)

setDateFormatClass

public static void setDateFormatClass(Class dateFormatClass)

You can override the DateFormat by specifying a class.

Parameters:

dateFormatClass - The class. This must be derived from java.text.DateFormat

setFormatPattern

public static void setFormatPattern(String pattern)

Set the format of the output of the toString() method. All DateTime objects created in the JVM once this is set will use the new format so be very careful in your use of this method. The pattern uses the time format syntax of java.text.SimpleDateFormat.

Parameters:

pattern - time format string

See Also:

If you want to use a time zone other than the default,, setFormatTimeZone(java.util.TimeZone)

getFormatPattern

public static String getFormatPattern()

Return the format pattern used in the output of the toString() method. The pattern uses the time format syntax of java.text.SimpleDateFormat.

Returns:

time format pattern

See Also:

SimpleDateFormat

setFormatTimeZone

public static void setFormatTimeZone(TimeZone tz)

Set the TimeZone of the output of the toString() method. All DateTime objects created in the JVM once this is set will use the new TimeZone so be very careful in your use of this method. The time zone is any of the valid java.util.TimeZone values.

Parameters:

tz - time zone

See Also:

TimeZone

getFormatTimeZone

public static TimeZone getFormatTimeZone()

Return the TimeZone used in the output of the toString() method.

Returns:

time zone

resetFormat

public static void resetFormat()

Reset the format of the output of the toString() method to the default - yyyy-MM-dd HH:mm:ssZ (ex: 1999-05-04 15:27:08Z) and the TimeZone to UTC.

createDateTime

public static DateTime createDateTime(String dateString)
                               throws VisADException

Create a DateTime object from a string specification

Parameters:

dateString - date string specification in format pattern defined for DateTime in this JVM

Throws:

VisADException - formatting problem

See Also:

setFormatPattern(java.lang.String)

createDateTime

public static DateTime createDateTime(String dateString,
                                      String format)
                               throws VisADException

Create a DateTime object from a string specification using the supplied pattern and default timezone.

Parameters:

dateString - date string specification

format - string

Throws:

VisADException - formatting problem

createDateTime

public static DateTime createDateTime(String dateString,
                                      String format,
                                      TimeZone timezone)
                               throws VisADException

Create a DateTime object from a string specification using the supplied pattern and timezone.

Parameters:

dateString - date string specification

format - format string

timezone - TimeZone to use

Throws:

VisADException - formatting problem

compareTo

public int compareTo(Object oo)

Implement Comparable interface

Specified by:

compareTo in interface Comparable

Specified by:

compareTo in interface RealIface

Overrides:

compareTo in class Real

Parameters:

oo - Object for comparison - should be DateTime

Returns:

A negative integer, zero, or a positive integer depending on whether this Real is considered less than, equal to, or greater than the other Real, respectively. If the values of the Real-s in the default unit are equal, then the ErrorEstimate.compareTo() method is used to break the tie.

makeTimeSet

public static Gridded1DDoubleSet makeTimeSet(DateTime[] times)
                                      throws VisADException

Create a Gridded1DDoubleSet from an array of DateTimes

Parameters:

times - array of DateTimes. Array cannot be null or only have one entry.

Returns:

Gridded1DDouble set representing the array

Throws:

VisADException - couldn't create the GriddedDoubleSet

makeTimeSet

public static Gridded1DDoubleSet makeTimeSet(double[] times)
                                      throws VisADException

Create a Gridded1DDoubleSet from an array of doubles of seconds since the epoch.

Parameters:

times - array of times in seconds since the epoch. Array cannot be null or only have one entry.

Returns:

set representing the array as a Gridded1DDoubleSet

Throws:

VisADException - couldn't create the GriddedDoubleSet

timeSetToArray

public static DateTime[] timeSetToArray(Gridded1DSet timeSet)
                                 throws VisADException

Create an array of DateTimes from a Gridded1DSet of times.

Parameters:

timeSet - Gridded1DSet of times

Throws:

VisADException - invalid time set or couldn't create DateTimes

main

public static void main(String[] args)
                 throws VisADException

run 'java visad.DateTime' to test the DateTime class

Throws:

VisADException