edu.uci.ics.jung.graph.util
Class Pair<T>

java.lang.Object
  edu.uci.ics.jung.graph.util.Pair<T>

All Implemented Interfaces:

Serializable, Iterable<T>, Collection<T>

public final class Pair<T>
extends Object
implements Collection<T>, Serializable

An implementation of Collection that stores exactly 2 non-null objects and is not mutable. They respect equals and may be used as indices or map keys.

Note that they do not protect from malevolent behavior: if one or another object in the tuple is mutable, then it can be changed with the usual bad effects.

See Also:

Serialized Form

Constructor Summary

Pair(Collection<? extends T> values)
Creates a Pair from the passed Collection.

Pair(T[] values)
Creates a Pair from the passed array.

Pair(T value1, T value2)
Creates a Pair from the specified elements.

Method Summary

boolean	add(T o)
boolean	addAll(Collection<? extends T> c)
void	clear()
boolean	contains(Object o)
boolean	containsAll(Collection<?> c)
boolean	equals(Object o)
T	getFirst() Returns the first element.
T	getSecond() Returns the second element.
int	hashCode()
boolean	isEmpty()
Iterator<T>	iterator()
boolean	remove(Object o)
boolean	removeAll(Collection<?> c)
boolean	retainAll(Collection<?> c)
int	size()
Object[]	toArray()
<S> S[]	toArray(S[] a)
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Pair

public Pair(T value1,
            T value2)

Creates a Pair from the specified elements.

Parameters:

value1 - the first value in the new Pair

value2 - the second value in the new Pair

Throws:

IllegalArgumentException - if either argument is null

Pair

public Pair(Collection<? extends T> values)

Creates a Pair from the passed Collection. The size of the Collection must be 2.

Parameters:

values - the elements of the new Pair

Throws:

IllegalArgumentException - if the input collection is null, contains null values, or has != 2 elements.

Pair

public Pair(T[] values)

Creates a Pair from the passed array. The size of the array must be 2.

Throws:

IllegalArgumentException - if the input array is null, contains null values, or has != 2 elements.

Method Detail

getFirst

public T getFirst()

Returns the first element.

getSecond

public T getSecond()

Returns the second element.

equals

public boolean equals(Object o)

Specified by:

equals in interface Collection<T>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<T>

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

add

public boolean add(T o)

Specified by:

add in interface Collection<T>

addAll

public boolean addAll(Collection<? extends T> c)

Specified by:

addAll in interface Collection<T>

clear

public void clear()

Specified by:

clear in interface Collection<T>

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<T>

containsAll

public boolean containsAll(Collection<?> c)

Specified by:

containsAll in interface Collection<T>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<T>

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>

Specified by:

iterator in interface Collection<T>

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection<T>

removeAll

public boolean removeAll(Collection<?> c)

Specified by:

removeAll in interface Collection<T>

retainAll

public boolean retainAll(Collection<?> c)

Specified by:

retainAll in interface Collection<T>

size

public int size()

Specified by:

size in interface Collection<T>

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<T>

toArray

public <S> S[] toArray(S[] a)

Specified by:

toArray in interface Collection<T>