org.joda.time.chrono
Class NonZeroDateTimeField

java.lang.Object
  |
  +--org.joda.time.DateTimeField
        |
        +--org.joda.time.chrono.NonZeroDateTimeField

All Implemented Interfaces:

java.io.Serializable

public final class NonZeroDateTimeField

extends DateTimeField

Wraps another field such that zero values are replaced with one more than it's maximum. This is particularly useful for implementing an clockhourOfDay field, where the midnight value of 0 is replaced with 24.

Since:

1.0

Author:

Brian S O'Neill

See Also:

Serialized Form

Constructor Summary

NonZeroDateTimeField(java.lang.String name, DateTimeField field)

Method Summary

long	add(long millis, int amount) Adds a value (which may be negative) to the millis value, overflowing into larger fields if necessary.
long	add(long millis, long amount) Adds a value (which may be negative) to the millis value, overflowing into larger fields if necessary.
long	addWrapped(long millis, int amount) Adds a value (which may be negative) to the millis value, wrapping within this field.
int	get(long millis) Get the value of this field from the milliseconds.
long	getDifference(long minuendMillis, long subtrahendMillis) Computes the difference between two instants, as measured in the units of this field.
DateTimeField	getField() Returns the DateTimeField being wrapped.
int	getMaximumValue() Get the maximum value for the field, which is one more than the wrapped field's maximum value.
int	getMaximumValue(long millis) Get the maximum value for the field, which is one more than the wrapped field's maximum value.
int	getMinimumValue() Always returns 1.
int	getMinimumValue(long millis) Always returns 1.
long	getRangeMillis() Returns the range of this field, in milliseconds.
long	getUnitMillis() Returns the amount of milliseconds per unit value of this field.
long	remainder(long millis) Retains only the fractional units of this field.
long	roundCeiling(long millis) Round to the highest whole unit of this field.
long	roundFloor(long millis) Round to the lowest whole unit of this field.
long	set(long millis, int value) Sets a value in the milliseconds supplied.

Methods inherited from class org.joda.time.DateTimeField

addLong, getAsShortText, getAsShortText, getAsText, getAsText, getLeapAmount, getMaximumShortTextLength, getMaximumTextLength, getName, getWrappedValue, getWrappedValue, isLeap, roundHalfCeiling, roundHalfEven, roundHalfFloor, set, set, toString, verifyValueBounds

Methods inherited from class java.lang.Object

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

Constructor Detail

NonZeroDateTimeField

public NonZeroDateTimeField(java.lang.String name,
                            DateTimeField field)

Parameters:

name - short, descriptive name, like "clockhourOfDay".

Throws:

java.lang.IllegalArgumentException - if wrapped field's minimum value is not zero

Method Detail

get

public int get(long millis)

Description copied from class: DateTimeField

Get the value of this field from the milliseconds.

Specified by:

get in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to query

Returns:

the value of the field, in the units of the field

add

public long add(long millis,
                int amount)

Description copied from class: DateTimeField

Adds a value (which may be negative) to the millis value, overflowing into larger fields if necessary.

The value will be added to this field. If the value is too large to be added solely to this field, larger fields will increase as required. Smaller fields should be unaffected, except where the result would be an invalid value for a smaller field. In this case the smaller field is adjusted to be in range.

For example, in the ISO chronology:
2000-08-20 add six months is 2001-02-20
2000-08-20 add twenty months is 2002-04-20
2000-08-20 add minus nine months is 1999-11-20
2001-01-31 add one month is 2001-02-28
2001-01-31 add two months is 2001-03-31

Specified by:

add in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to add to

amount - the value to add, in the units of the field

Returns:

the updated milliseconds

add

public long add(long millis,
                long amount)

Description copied from class: DateTimeField

Adds a value (which may be negative) to the millis value, overflowing into larger fields if necessary.

Specified by:

add in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to add to

amount - the long value to add, in the units of the field

Returns:

the updated milliseconds

See Also:

DateTimeField.add(long,int)

addWrapped

public long addWrapped(long millis,
                       int amount)

Description copied from class: DateTimeField

Adds a value (which may be negative) to the millis value, wrapping within this field.

The value will be added to this field. If the value is too large to be added solely to this field then it wraps. Larger fields are always unaffected. Smaller fields should be unaffected, except where the result would be an invalid value for a smaller field. In this case the smaller field is adjusted to be in range.

For example, in the ISO chronology:
2000-08-20 addWrapped six months is 2000-02-20
2000-08-20 addWrapped twenty months is 2000-04-20
2000-08-20 addWrapped minus nine months is 2000-11-20
2001-01-31 addWrapped one month is 2001-02-28
2001-01-31 addWrapped two months is 2001-03-31

Overrides:

addWrapped in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to add to

amount - the value to add, in the units of the field

Returns:

the updated milliseconds

getDifference

public long getDifference(long minuendMillis,
                          long subtrahendMillis)

Description copied from class: DateTimeField

Computes the difference between two instants, as measured in the units of this field. Any fractional units are dropped from the result. Calling getDifference reverses the effect of calling add. In the following code:

 long millis = ...
 int v = ...
 long age = getDifference(add(millis, v), millis);
 

The value 'age' is the same as the value 'v'.

The default implementation performs a guess-and-check algorithm using the getUnitMillis and add methods. Subclasses are encouraged to provide a more efficient implementation.

Overrides:

getDifference in class DateTimeField

Parameters:

minuendMillis - the milliseconds from 1970-01-01T00:00:00Z to subtract from

subtrahendMillis - the milliseconds from 1970-01-01T00:00:00Z to subtract off the minuend

Returns:

the difference in the units of this field

set

public long set(long millis,
                int value)

Description copied from class: DateTimeField

Sets a value in the milliseconds supplied.

The value of this field will be set. If the value is invalid, an exception if thrown. Other fields are always unaffected.

Specified by:

set in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to set in

value - the value to set, in the units of the field

Returns:

the updated milliseconds

getUnitMillis

public long getUnitMillis()

Description copied from class: DateTimeField

Returns the amount of milliseconds per unit value of this field. For example, if this field represents "hour of day", then the unit is the amount of milliseconds per one hour.

For fields with a variable unit size, this method returns a suitable average value.

Specified by:

getUnitMillis in class DateTimeField

Returns:

the unit size of this field, in milliseconds

getRangeMillis

public long getRangeMillis()

Description copied from class: DateTimeField

Returns the range of this field, in milliseconds. For example, if this field represents "hour of day", then the range is the amount of milliseconds per one day.

For fields with a variable range, this method returns a suitable average value. If the range is too large to fit in a long, Long.MAX_VALUE is returned.

Specified by:

getRangeMillis in class DateTimeField

Returns:

the range of this field, in milliseconds

getMinimumValue

public int getMinimumValue()

Always returns 1.

Specified by:

getMinimumValue in class DateTimeField

Returns:

the minimum value of 1

getMinimumValue

public int getMinimumValue(long millis)

Always returns 1.

Overrides:

getMinimumValue in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to query

Returns:

the minimum value of 1

getMaximumValue

public int getMaximumValue()

Get the maximum value for the field, which is one more than the wrapped field's maximum value.

Specified by:

getMaximumValue in class DateTimeField

Returns:

the maximum value

getMaximumValue

public int getMaximumValue(long millis)

Get the maximum value for the field, which is one more than the wrapped field's maximum value.

Overrides:

getMaximumValue in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to query

Returns:

the maximum value

roundFloor

public long roundFloor(long millis)

Description copied from class: DateTimeField

Round to the lowest whole unit of this field. After rounding, the value of this field and all fields of a higher magnitude are retained. The fractional millis that cannot be expressed in whole increments of this field are set to minimum.

For example, a datetime of 2002-11-02T23:34:56.789, rounded to the lowest whole hour is 2002-11-02T23:00:00.000.

Specified by:

roundFloor in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to round

Returns:

rounded milliseconds

roundCeiling

public long roundCeiling(long millis)

Description copied from class: DateTimeField

Round to the highest whole unit of this field. The value of this field and all fields of a higher magnitude may be incremented in order to achieve this result. The fractional millis that cannot be expressed in whole increments of this field are set to minimum.

For example, a datetime of 2002-11-02T23:34:56.789, rounded to the highest whole hour is 2002-11-03T00:00:00.000.

The default implementation calls roundFloor, and if the millis is modified as a result, adds one field unit. Subclasses are encouraged to provide a more efficient implementation.

Overrides:

roundCeiling in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to round

Returns:

rounded milliseconds

remainder

public long remainder(long millis)

Description copied from class: DateTimeField

Retains only the fractional units of this field. This field value and all fields of higher magnitude are reset. In other words, calling remainder retains the part of the instant that roundFloor dropped.

For example, a datetime of 2002-11-02T23:34:56.789, the remainder by hour is 1970-01-01T00:34:56.789.

The default implementation computes millis - roundFloor(millis). Subclasses are encouraged to provide a more efficient implementation.

Overrides:

remainder in class DateTimeField

Parameters:

millis - the milliseconds from 1970-01-01T00:00:00Z to get the remainder

Returns:

remainder milliseconds

getField

public DateTimeField getField()

Returns the DateTimeField being wrapped.

Returns:

field