org.apache.commons.lang3.tuple

Class ImmutablePair<L,R>

java.lang.Object

org.apache.commons.lang3.tuple.Pair<L,R>

org.apache.commons.lang3.tuple.ImmutablePair<L,R>

Type Parameters:

L - the left element type

R - the right element type

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<Pair<L,R>>, java.util.Map.Entry<L,R>

public final class ImmutablePair<L,R>
extends Pair<L,R>

An immutable pair consisting of two Object elements.

Although the implementation is immutable, there is no restriction on the objects that may be stored. If mutable objects are stored in the pair, then the pair itself effectively becomes mutable. The class is also final, so a subclass can not add undesirable behaviour.

#ThreadSafe# if both paired objects are thread-safe

Since:

3.0

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
L	left Left object
R	right Right object

Constructor Summary

Constructors

Constructor and Description
ImmutablePair(L left, R right) Create a new pair instance.

Method Summary

Modifier and Type	Method and Description
L	getLeft() Gets the left element from this pair.
R	getRight() Gets the right element from this pair.
static <L,R> ImmutablePair<L,R>	nullPair() Returns an immutable pair of nulls.
static <L,R> ImmutablePair<L,R>	of(L left, R right) Obtains an immutable pair of two objects inferring the generic types.
R	setValue(R value) Throws UnsupportedOperationException.

Methods inherited from class org.apache.commons.lang3.tuple.Pair

compareTo, equals, getKey, getValue, hashCode, toString, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map.Entry

comparingByKey, comparingByKey, comparingByValue, comparingByValue

Field Detail

left

public final L left

Left object

right

public final R right

Right object

Constructor Detail

ImmutablePair

public ImmutablePair(L left,
                     R right)

Create a new pair instance.

Parameters:

left - the left value, may be null

right - the right value, may be null

Method Detail

nullPair

public static <L,R> ImmutablePair<L,R> nullPair()

Returns an immutable pair of nulls.

Type Parameters:

L - the left element of this pair. Value is null.

R - the right element of this pair. Value is null.

Returns:

an immutable pair of nulls.

Since:

3.6

of

public static <L,R> ImmutablePair<L,R> of(L left,
                                          R right)

Obtains an immutable pair of two objects inferring the generic types.

This factory allows the pair to be created using inference to obtain the generic types.

Type Parameters:

L - the left element type

R - the right element type

Parameters:

left - the left element, may be null

right - the right element, may be null

Returns:

a pair formed from the two parameters, not null

getLeft

public L getLeft()

Gets the left element from this pair.

When treated as a key-value pair, this is the key.

Specified by:

getLeft in class Pair<L,R>

Returns:

the left element, may be null

getRight

public R getRight()

Gets the right element from this pair.

When treated as a key-value pair, this is the value.

Specified by:

getRight in class Pair<L,R>

Returns:

the right element, may be null

setValue

public R setValue(R value)

Throws UnsupportedOperationException.

This pair is immutable, so this operation is not supported.

Parameters:

value - the value to set

Returns:

never

Throws:

java.lang.UnsupportedOperationException - as this operation is not supported