org.apache.commons.math3.util

Class Pair<K,V>

java.lang.Object

org.apache.commons.math3.util.Pair<K,V>

Type Parameters:

K - Key type.

V - Value type.

Direct Known Subclasses:

PointValuePair, PointValuePair, PointVectorValuePair, PointVectorValuePair

public class Pair<K,V>
extends java.lang.Object

Generic pair.
Although the instances of this class are immutable, it is impossible to ensure that the references passed to the constructor will not be modified by the caller.

Since:

3.0

Field Summary

Fields

Modifier and Type	Field and Description
private K	key Key.
private V	value Value.

Constructor Summary

Constructors

Constructor and Description
Pair(K k, V v) Create an entry representing a mapping from the specified key to the specified value.
Pair(Pair<? extends K,? extends V> entry) Create an entry representing the same mapping as the specified entry.

Method Summary

Methods

Modifier and Type	Method and Description
static <K,V> Pair<K,V>	create(K k, V v) Convenience factory method that calls the constructor.
boolean	equals(java.lang.Object o) Compare the specified object with this entry for equality.
K	getFirst() Get the first element of the pair.
K	getKey() Get the key.
V	getSecond() Get the second element of the pair.
V	getValue() Get the value.
int	hashCode() Compute a hash code.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

key

private final K key

Key.

value

private final V value

Value.

Constructor Detail

Pair

public Pair(K k,
    V v)

Create an entry representing a mapping from the specified key to the specified value.

Parameters:

k - Key (first element of the pair).

v - Value (second element of the pair).

Pair

public Pair(Pair<? extends K,? extends V> entry)

Create an entry representing the same mapping as the specified entry.

Parameters:

entry - Entry to copy.

Method Detail

getKey

public K getKey()

Get the key.

Returns:

the key (first element of the pair).

getValue

public V getValue()

Get the value.

Returns:

the value (second element of the pair).

getFirst

public K getFirst()

Get the first element of the pair.

Returns:

the first element of the pair.

Since:

3.1

getSecond

public V getSecond()

Get the second element of the pair.

Returns:

the second element of the pair.

Since:

3.1

equals

public boolean equals(java.lang.Object o)

Compare the specified object with this entry for equality.

Overrides:

equals in class java.lang.Object

Parameters:

o - Object.

Returns:

true if the given object is also a map entry and the two entries represent the same mapping.

hashCode

public int hashCode()

Compute a hash code.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code value.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

create

public static <K,V> Pair<K,V> create(K k,
                     V v)

Convenience factory method that calls the constructor.

Type Parameters:

K - the key type

V - the value type

Parameters:

k - First element of the pair.

v - Second element of the pair.

Returns:

a new Pair containing k and v.

Since:

3.3