DurationField (Joda-Time 2.10.3 API)

java.lang.Object
- org.joda.time.DurationField

All Implemented Interfaces:

Comparable<DurationField>

Direct Known Subclasses:

BaseDurationField, DelegatedDurationField, MillisDurationField, UnsupportedDurationField
```
public abstract class DurationField
extends Object
implements Comparable<DurationField>
```
Defines the calculation engine for duration fields. The interface defines a set of methods that manipulate a millisecond duration with regards to a single field, such as months or seconds.
This design is extensible so, if you wish, you can extract a different field from the millisecond duration. A number of standard implementations are provided to assist.

Since:

1.0

Constructor Summary

Constructors
Constructor and Description

DurationField()

Constructors
Constructor and Description
`DurationField()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract long`	`add(long instant, int value)` Adds a duration value (which may be negative) to the instant.
`abstract long`	`add(long instant, long value)` Adds a duration 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 long`	`getMillis(int value)` Get the millisecond duration of this field from its value, which is approximate if this field is imprecise.
`abstract long`	`getMillis(int value, long instant)` Get the millisecond duration of this field from its value relative to an instant.
`abstract long`	`getMillis(long value)` Get the millisecond duration of this field from its value, which is approximate if this field is imprecise.
`abstract long`	`getMillis(long value, long instant)` Get the millisecond duration of this field from its value relative to an instant.
`abstract String`	`getName()` Get the name of the field.
`abstract DurationFieldType`	`getType()` Get the type of the field.
`abstract long`	`getUnitMillis()` Returns the amount of milliseconds per unit value of this field.
`abstract int`	`getValue(long duration)` Get the value of this field from the milliseconds, which is approximate if this field is imprecise.
`abstract int`	`getValue(long duration, long instant)` Get the value of this field from the milliseconds relative to an instant.
`abstract long`	`getValueAsLong(long duration)` Get the value of this field from the milliseconds, which is approximate if this field is imprecise.
`abstract long`	`getValueAsLong(long duration, long instant)` Get the value of this field from the milliseconds relative to an instant.
`abstract boolean`	`isPrecise()` Is this field precise.
`abstract boolean`	`isSupported()` Returns true if this field is supported.
`long`	`subtract(long instant, int value)` Subtracts a duration value (which may be negative) from the instant.
`long`	`subtract(long instant, long value)` Subtracts a duration value (which may be negative) from the instant.
`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

Methods inherited from interface java.lang.Comparable
compareTo

- Constructor Detail
  - DurationField
```
public DurationField()
```
- Method Detail
  - getType
```
public abstract DurationFieldType getType()
```
    Get the type of the field.
    
    Returns:
    
    field type
  - 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
  - isPrecise
```
public abstract boolean isPrecise()
```
    Is this field precise. A precise field can calculate its value from milliseconds without needing a reference date. Put another way, a precise field's unit size is not variable.
    
    Returns:
    
    true if precise
    
    See Also:
    
    getUnitMillis()
  - getUnitMillis
```
public abstract long getUnitMillis()
```
    Returns the amount of milliseconds per unit value of this field. For example, if this field represents "seconds", then this returns the milliseconds in one second.
    For imprecise fields, the unit size is variable, and so this method returns a suitable average value.
    
    Returns:
    
    the unit size of this field, in milliseconds
    
    See Also:
    
    isPrecise()
  - getValue
```
public abstract int getValue(long duration)
```
    Get the value of this field from the milliseconds, which is approximate if this field is imprecise.
    
    Parameters:
    
    duration - the milliseconds to query, which may be negative
    
    Returns:
    
    the value of the field, in the units of the field, which may be negative
    
    Throws:
    
    ArithmeticException - if the value is too large for an int
  - getValueAsLong
```
public abstract long getValueAsLong(long duration)
```
    Get the value of this field from the milliseconds, which is approximate if this field is imprecise.
    
    Parameters:
    
    duration - the milliseconds to query, which may be negative
    
    Returns:
    
    the value of the field, in the units of the field, which may be negative
  - getValue
```
public abstract int getValue(long duration,
                             long instant)
```
    Get the value of this field from the milliseconds relative to an instant. For precise fields this method produces the same result as for the single argument get method.
    If the millisecond duration is positive, then the instant is treated as a "start instant". If negative, the instant is treated as an "end instant".
    
    Parameters:
    
    duration - the milliseconds to query, which may be negative
    
    instant - the start instant to calculate relative to
    
    Returns:
    
    the value of the field, in the units of the field, which may be negative
    
    Throws:
    
    ArithmeticException - if the value is too large for an int
  - getValueAsLong
```
public abstract long getValueAsLong(long duration,
                                    long instant)
```
    Get the value of this field from the milliseconds relative to an instant. For precise fields this method produces the same result as for the single argument get method.
    If the millisecond duration is positive, then the instant is treated as a "start instant". If negative, the instant is treated as an "end instant".
    
    Parameters:
    
    duration - the milliseconds to query, which may be negative
    
    instant - the start instant to calculate relative to
    
    Returns:
    
    the value of the field, in the units of the field, which may be negative
  - getMillis
```
public abstract long getMillis(int value)
```
    Get the millisecond duration of this field from its value, which is approximate if this field is imprecise.
    
    Parameters:
    
    value - the value of the field, which may be negative
    
    Returns:
    
    the milliseconds that the field represents, which may be negative
  - getMillis
```
public abstract long getMillis(long value)
```
    Get the millisecond duration of this field from its value, which is approximate if this field is imprecise.
    
    Parameters:
    
    value - the value of the field, which may be negative
    
    Returns:
    
    the milliseconds that the field represents, which may be negative
  - getMillis
```
public abstract long getMillis(int value,
                               long instant)
```
    Get the millisecond duration of this field from its value relative to an instant. For precise fields this method produces the same result as for the single argument getMillis method.
    If the value is positive, then the instant is treated as a "start instant". If negative, the instant is treated as an "end instant".
    
    Parameters:
    
    value - the value of the field, which may be negative
    
    instant - the instant to calculate relative to
    
    Returns:
    
    the millisecond duration that the field represents, which may be negative
  - getMillis
```
public abstract long getMillis(long value,
                               long instant)
```
    Get the millisecond duration of this field from its value relative to an instant. For precise fields this method produces the same result as for the single argument getMillis method.
    If the value is positive, then the instant is treated as a "start instant". If negative, the instant is treated as an "end instant".
    
    Parameters:
    
    value - the value of the field, which may be negative
    
    instant - the instant to calculate relative to
    
    Returns:
    
    the millisecond duration that the field represents, which may be negative
  - add
```
public abstract long add(long instant,
                         int value)
```
    Adds a duration 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 duration 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
  - subtract
```
public long subtract(long instant,
                     int value)
```
    Subtracts a duration value (which may be negative) from the instant.
    
    Parameters:
    
    instant - the milliseconds from 1970-01-01T00:00:00Z to subtract from
    
    value - the value to subtract, in the units of the field
    
    Returns:
    
    the updated milliseconds
    
    Since:
    
    1.1
  - subtract
```
public long subtract(long instant,
                     long value)
```
    Subtracts a duration value (which may be negative) from the instant.
    
    Parameters:
    
    instant - the milliseconds from 1970-01-01T00:00:00Z to subtract from
    
    value - the value to subtract, in the units of the field
    
    Returns:
    
    the updated milliseconds
    
    Since:
    
    1.1
  - 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
  - toString
```
public abstract String toString()
```
    Get a suitable debug string.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    debug string

Class DurationField

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Comparable

Constructor Detail

DurationField

Method Detail

getType

getName

isSupported

isPrecise

getUnitMillis

getValue

getValueAsLong

getValue

getValueAsLong

getMillis

getMillis

getMillis

getMillis

add

add

subtract

subtract

getDifference

getDifferenceAsLong

toString