org.goda.time

Class Field

java.lang.Object

org.goda.time.Field

Direct Known Subclasses:

DateTimeField, DurationField

public abstract class Field
extends Object

Author:

joneg01

Constructor Summary

Constructors

Constructor and Description
Field()

Method Summary

Methods

Modifier and Type	Method and Description
abstract long	add(long instant, int value) Adds a value (which may be negative) to the instant.
abstract long	add(long instant, long value) Adds a value (which may be negative) to the instant.
abstract int	getDifference(long minuendInstant, long subtrahendInstant) Computes the difference between two instants, as measured in the units of this field.
abstract long	getDifferenceAsLong(long minuendInstant, long subtrahendInstant) Computes the difference between two instants, as measured in the units of this field.
abstract String	getName() Get the name of the field.
abstract boolean	isSupported() Returns true if this field is supported.
abstract String	toString() Get a suitable debug string.

Methods inherited from class java.lang.Object

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

Constructor Detail

Field

public Field()

Method Detail

getName

public abstract String getName()

Get the name of the field.

By convention, names are plural.

Returns:

field name

isSupported

public abstract boolean isSupported()

Returns true if this field is supported.

Returns:

true if this field is supported

getDifference

public abstract int getDifference(long minuendInstant,
                long subtrahendInstant)

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 instant = ...
 int v = ...
 int age = getDifference(add(instant, v), instant);
 

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

Parameters:

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

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

Returns:

the difference in the units of this field

getDifferenceAsLong

public abstract long getDifferenceAsLong(long minuendInstant,
                       long subtrahendInstant)

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 instant = ...
 long v = ...
 long age = getDifferenceAsLong(add(instant, v), instant);
 

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

Parameters:

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

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

Returns:

the difference in the units of this field

add

public abstract long add(long instant,
       int value)

Adds a value (which may be negative) to the instant.

Parameters:

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

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

Returns:

the updated milliseconds

add

public abstract long add(long instant,
       long value)

Adds a value (which may be negative) to the instant.

Parameters:

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

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

Returns:

the updated milliseconds

toString

public abstract String toString()

Get a suitable debug string.

Overrides:

toString in class Object

Returns:

debug string