Package org.djutils.immutablecollections

Class ImmutableMap.ImmutableEntry<K,V>

java.lang.Object

org.djutils.immutablecollections.ImmutableMap.ImmutableEntry<K,V>

Type Parameters:

K - key

V - value

Enclosing interface:

ImmutableMap<K,V>

public static class ImmutableMap.ImmutableEntry<K,V>
extends Object

A map entry (key-value pair). The Map.entrySet method returns a collection-view of the map, whose elements are of this class. The only way to obtain a reference to a map entry is from the iterator of this collection-view. These ImmutableMap.ImmutableEntry objects are valid only for the duration of the iteration; more formally, the behavior of a map entry is undefined if the backing map has been modified after the entry was returned by the iterator, except through the setValue operation on the map entry.

Constructor Summary

Constructors

Constructor	Description
ImmutableEntry(Map.Entry<K,V> wrappedEntry)

Method Summary

Modifier and Type	Method	Description
static <K extends Comparable<? super K>,V> Comparator<ImmutableMap.ImmutableEntry<K,V>>	comparingByKey()	Returns a comparator that compares ImmutableMap.ImmutableEntry in natural order on key.
static <K,V> Comparator<ImmutableMap.ImmutableEntry<K,V>>	comparingByKey(Comparator<? super K> cmp)	Returns a comparator that compares ImmutableMap.ImmutableEntry by key using the given Comparator.
static <K,V extends Comparable<? super V>> Comparator<ImmutableMap.ImmutableEntry<K,V>>	comparingByValue()	Returns a comparator that compares ImmutableMap.ImmutableEntry in natural order on value.
static <K,V> Comparator<ImmutableMap.ImmutableEntry<K,V>>	comparingByValue(Comparator<? super V> cmp)	Returns a comparator that compares ImmutableMap.ImmutableEntry by value using the given Comparator.
boolean	equals(Object obj)
K	getKey()	Returns the key corresponding to this entry.
V	getValue()	Returns the value corresponding to this entry.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ImmutableEntry

public ImmutableEntry(Map.Entry<K,V> wrappedEntry)

Parameters:

wrappedEntry - Entry<K,V>; the wrapped entry

Method Detail

getKey

public K getKey()

Returns the key corresponding to this entry.

Returns:

the key corresponding to this entry

Throws:

IllegalStateException - implementations may, but are not required to, throw this exception if the entry has been removed from the backing map.

getValue

public V getValue()

Returns the value corresponding to this entry. If the mapping has been removed from the backing map (by the iterator's remove operation), the results of this call are undefined.

Returns:

the value corresponding to this entry

Throws:

IllegalStateException - implementations may, but are not required to, throw this exception if the entry has been removed from the backing map.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

comparingByKey

public static <K extends Comparable<? super K>,V> Comparator<ImmutableMap.ImmutableEntry<K,V>> comparingByKey()

Returns a comparator that compares ImmutableMap.ImmutableEntry in natural order on key.

The returned comparator is serializable and throws NullPointerException when comparing an entry with a null key.

Type Parameters:

K - the Comparable type of then map keys

V - the type of the map values

Returns:

a comparator that compares ImmutableMap.ImmutableEntry in natural order on key.

Since:

1.8

See Also:

Comparable

comparingByValue

public static <K,V extends Comparable<? super V>> Comparator<ImmutableMap.ImmutableEntry<K,V>> comparingByValue()

Returns a comparator that compares ImmutableMap.ImmutableEntry in natural order on value.

The returned comparator is serializable and throws NullPointerException when comparing an entry with null values.

Type Parameters:

K - the type of the map keys

V - the Comparable type of the map values

Returns:

a comparator that compares ImmutableMap.ImmutableEntry in natural order on value.

Since:

1.8

See Also:

Comparable

comparingByKey

public static <K,V> Comparator<ImmutableMap.ImmutableEntry<K,V>> comparingByKey(Comparator<? super K> cmp)

Returns a comparator that compares ImmutableMap.ImmutableEntry by key using the given Comparator.

The returned comparator is serializable if the specified comparator is also serializable.

Type Parameters:

K - the type of the map keys

V - the type of the map values

Parameters:

cmp - Comparator<? super K>; the key Comparator

Returns:

a comparator that compares ImmutableMap.ImmutableEntry by the key.

Since:

1.8

comparingByValue

public static <K,V> Comparator<ImmutableMap.ImmutableEntry<K,V>> comparingByValue(Comparator<? super V> cmp)

Returns a comparator that compares ImmutableMap.ImmutableEntry by value using the given Comparator.

The returned comparator is serializable if the specified comparator is also serializable.

Type Parameters:

K - the type of the map keys

V - the type of the map values

Parameters:

cmp - Comparator<? super V>; the value Comparator

Returns:

a comparator that compares ImmutableMap.ImmutableEntry by the value.

Since:

1.8

toString

public String toString()

Overrides:

toString in class Object