de.alpharogroup.collections.map

Class MapExtensions

java.lang.Object

de.alpharogroup.collections.map.MapExtensions

public final class MapExtensions
extends java.lang.Object

Extensions class for use with Map objects.

Method Summary

Modifier and Type	Method and Description
static <K,V> K	getKeyFromValue(java.util.Map<K,V> map, V value) Returns the first founded key from the given value or null if nothing is found.
static <K,V> java.util.Collection<K>	getKeysFromValue(java.util.Map<K,V> map, V value) Returns a Collection from all founded keys from the given value or null if nothing found.
static <K> java.util.Map<K,java.lang.Integer>	mergeAndSummarize(java.util.Map<K,java.lang.Integer> valueCounterMap, java.util.Map<K,java.lang.Integer> summarizeWithThisValueCounterMap) Factory method for create a map for counting elements of the given collection
static <K> java.util.Map<K,java.lang.Integer>	mergeAndSummarize(java.util.Map<K,java.lang.Integer> valueCounterMap, java.util.Map<K,java.lang.Integer> summarizeWithThisValueCounterMap, boolean fullMerge) Factory method for create a map for counting elements of the given collection
static <K,V extends java.lang.Comparable<? super V>> java.util.Map<K,V>	sortByValue(java.util.Map<K,V> map, boolean reversed) Sort the given Map by its values and returns a sorted list by the values of the given Map
static <K,V extends java.lang.Comparable<? super V>> java.util.Map<K,V>	sortByValue(java.util.Map<K,V> map, java.util.Comparator<? super V> comparator) Sort the given Map by its values and returns a sorted list by the values of the given Map
static <K,V extends java.lang.Comparable<? super V>> java.util.List<java.util.Map.Entry<K,V>>	sortByValueAsList(java.util.Map<K,V> map, boolean reversed) Sort the given Map by its values and returns a sorted list by the values of the given Map
static <K,V extends java.lang.Comparable<? super V>> java.util.List<java.util.Map.Entry<K,V>>	sortByValueAsList(java.util.Map<K,V> map, java.util.Comparator<? super V> comparator) Sort the given Map by its values and returns a sorted list by the values of the given Map
static <T> java.util.Map<T,T>	toGenericMap(T[][] twoDimArray) Converts a two dimensional Array to a Map.
static java.util.Map<java.lang.String,java.lang.String>	toMap(java.lang.String[][] twoDimArray) Converts a two dimensional String Array to a Map.

Methods inherited from class java.lang.Object

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

Method Detail

getKeyFromValue

public static <K,V> K getKeyFromValue(java.util.Map<K,V> map,
                                      V value)

Returns the first founded key from the given value or null if nothing is found.

Type Parameters:

K - the generic type of the key

V - the generic type of the value

Parameters:

map - The Map.

value - The value.

Returns:

Returns the first key from the given value or null if nothing found.

getKeysFromValue

public static <K,V> java.util.Collection<K> getKeysFromValue(java.util.Map<K,V> map,
                                                             V value)

Returns a Collection from all founded keys from the given value or null if nothing found.

Type Parameters:

K - the generic type of the key

V - the generic type of the value

Parameters:

map - The Map.

value - The value.

Returns:

Returns the key from the given value or an empty Collection if nothing found.

mergeAndSummarize

public static <K> java.util.Map<K,java.lang.Integer> mergeAndSummarize(java.util.Map<K,java.lang.Integer> valueCounterMap,
                                                                       java.util.Map<K,java.lang.Integer> summarizeWithThisValueCounterMap)

Factory method for create a map for counting elements of the given collection

Type Parameters:

K - the generic type of the elements

Parameters:

valueCounterMap - the counter map

summarizeWithThisValueCounterMap - the other counter map that will be summarized with the first map

Returns:

the new map ready to count elements

mergeAndSummarize

public static <K> java.util.Map<K,java.lang.Integer> mergeAndSummarize(java.util.Map<K,java.lang.Integer> valueCounterMap,
                                                                       java.util.Map<K,java.lang.Integer> summarizeWithThisValueCounterMap,
                                                                       boolean fullMerge)

Factory method for create a map for counting elements of the given collection

Type Parameters:

K - the generic type of the elements

Parameters:

valueCounterMap - the counter map

summarizeWithThisValueCounterMap - the other counter map that will be summarized with the first map

fullMerge - if true all keys from both maps will be considered by the merge otherwise only the keys of the first map will be considered

Returns:

the new map ready to count elements

sortByValue

public static <K,V extends java.lang.Comparable<? super V>> java.util.Map<K,V> sortByValue(java.util.Map<K,V> map,
                                                                                           boolean reversed)

Sort the given Map by its values and returns a sorted list by the values of the given Map

Type Parameters:

K - the generic type of the key

V - the generic type of the value

Parameters:

map - the Map to sort

reversed - the flag if the result should be in reversed order

Returns:

a sorted Map by the values of the given Map

sortByValue

public static <K,V extends java.lang.Comparable<? super V>> java.util.Map<K,V> sortByValue(java.util.Map<K,V> map,
                                                                                           java.util.Comparator<? super V> comparator)

Sort the given Map by its values and returns a sorted list by the values of the given Map

Type Parameters:

K - the generic type of the key

V - the generic type of the value

Parameters:

map - the Map to sort

comparator - the comparator to sort

Returns:

a sorted Map by the values of the given Map

sortByValueAsList

public static <K,V extends java.lang.Comparable<? super V>> java.util.List<java.util.Map.Entry<K,V>> sortByValueAsList(java.util.Map<K,V> map,
                                                                                                                       boolean reversed)

Sort the given Map by its values and returns a sorted list by the values of the given Map

Type Parameters:

K - the generic type of the key

V - the generic type of the value

Parameters:

map - The Map to sort

reversed - the flag if the result should be in reversed order

Returns:

a sorted list by the values of the given Map

sortByValueAsList

public static <K,V extends java.lang.Comparable<? super V>> java.util.List<java.util.Map.Entry<K,V>> sortByValueAsList(java.util.Map<K,V> map,
                                                                                                                       java.util.Comparator<? super V> comparator)

Sort the given Map by its values and returns a sorted list by the values of the given Map

Type Parameters:

K - the generic type of the key

V - the generic type of the value

Parameters:

map - The Map to sort

comparator - the comparator to sort

Returns:

a sorted list by the values of the given Map

toGenericMap

public static <T> java.util.Map<T,T> toGenericMap(T[][] twoDimArray)

Converts a two dimensional Array to a Map.

Type Parameters:

T - the generic type

Parameters:

twoDimArray - The two dimensional Array.

Returns:

The map produced from the two dimensional Array.

toMap

public static java.util.Map<java.lang.String,java.lang.String> toMap(java.lang.String[][] twoDimArray)

Converts a two dimensional String Array to a Map.

Parameters:

twoDimArray - The two dimensional String Array.

Returns:

The map produced from the two dimensional String Array.