java8.util

Class Maps.Entry

java.lang.Object

java8.util.Maps.Entry

Enclosing class:

Maps

public static final class Maps.Entry
extends Object

A place for the static interface methods of the Java 8 Map.Entry interface.

Method Summary

Modifier and Type	Method and Description
static <K extends Comparable<? super K>,V> Comparator<Map.Entry<K,V>>	comparingByKey() Returns a comparator that compares Map.Entry in natural order on key.
static <K,V> Comparator<Map.Entry<K,V>>	comparingByKey(Comparator<? super K> cmp) Returns a comparator that compares Map.Entry by key using the given Comparator.
static <K,V extends Comparable<? super V>> Comparator<Map.Entry<K,V>>	comparingByValue() Returns a comparator that compares Map.Entry in natural order on value.
static <K,V> Comparator<Map.Entry<K,V>>	comparingByValue(Comparator<? super V> cmp) Returns a comparator that compares Map.Entry by value using the given Comparator.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

comparingByKey

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

Returns a comparator that compares Map.Entry 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 Map.Entry in natural order on key.

Since:

1.8

See Also:

Comparable

comparingByValue

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

Returns a comparator that compares Map.Entry 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 Map.Entry in natural order on value.

Since:

1.8

See Also:

Comparable

comparingByKey

public static <K,V> Comparator<Map.Entry<K,V>> comparingByKey(Comparator<? super K> cmp)

Returns a comparator that compares Map.Entry 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 - the key Comparator

Returns:

a comparator that compares Map.Entry by the key.

Since:

1.8

comparingByValue

public static <K,V> Comparator<Map.Entry<K,V>> comparingByValue(Comparator<? super V> cmp)

Returns a comparator that compares Map.Entry 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 - the value Comparator

Returns:

a comparator that compares Map.Entry by the value.

Since:

1.8