Package org.n52.shetland.util

Class CollectionHelper

java.lang.Object

org.n52.shetland.util.CollectionHelper

public final class CollectionHelper
extends Object

Since:

1.0.0

Method Summary

Modifier and Type	Method	Description
static <K,V> void	addToCollectionMap(K key, V valueToAdd, Map<K,Collection<V>> map)	Add a value to a map collection, initializing the key's collection if needed
static String	collectionToString(Collection<?> collection)
static <T> List<T>	conjunctCollections(Collection<T> list1, Collection<T> list2)
static <T> Set<T>	conjunctCollectionsToSet(Collection<T> list1, Collection<T> list2)
static List<String>	csvStringToList(String csv)	Parse CSV string to List
static Set<String>	csvStringToSet(String csv)	Parse CSV string to Set
static <T> Set<T>	intersection(Iterable<Set<T>> sets)
static <T> Set<T>	intersection(Set<T>... elements)
static <T> boolean	isEmpty(Collection<T> collection)	Check if collection is not null and empty
static <K,V> boolean	isEmpty(Map<K,V> map)	Check if map is not null and empty
static <T> boolean	isEmptyOrNull(Collection<T> collection)
static <T> boolean	isNotEmpty(Collection<T> collection)	Check if collection is not null and not empty
static <K,V> boolean	isNotEmpty(Map<K,V> map)	Check if collection is not null and not empty
static boolean	isNotNullOrEmpty(Object[] array)	Check if array is not null and not empty
static boolean	isNullOrEmpty(Object[] array)	Check if array is not null or not empty
static <T> List<T>	list(T... elements)
static <K,V> Map<K,V>	map(Map.Entry<K,V>... entries)
static <T extends Comparable<? super T>> SortedSet<T>	newSortedSet(Collection<? extends T> set)
static boolean	nullEmptyOrContainsOnlyNulls(Collection<? extends Object> collection)	Examine a collection and determines if it is null, empty, or contains only null values
static <K,V> Map<V,K>	reverse(Map<K,V> map)	Reverses a map (switches key and value types).
static <T> Set<T>	set(T... elements)
static <K,V extends Comparable<? super V>> Map<K,V>	sortByValue(Map<K,V> map)
static String[]	svStringToArray(String sv, String separator)	Parse separated value string to array with trimmed values
static List<String>	svStringToList(String sv, String separator)	Parse separated value string to List
static Set<String>	svStringToSet(String sv, String separator)	Parse separated value string to Set
static <K,V> Map<K,V>	synchronizedInitialSizeMapWithLoadFactor1(int capacity)
static <E> List<E>	synchronizedList()	Constructs a new synchronized List based on a LinkedList.
static <E> List<E>	synchronizedList(int initialCapacity)	Constructs a new synchronized List based on a ArrayList with the specified initialCapacity.
static <K,V> Map<K,V>	synchronizedMap()
static <K,V> Map<K,V>	synchronizedMap(int initialCapacity)
static <K,V> Map<K,V>	synchronizedMap(int initialCapacity, float loadFactor)
static <T> Set<T>	synchronizedSet()	Constructs a new synchronized Set based on a HashSet.
static <T> Set<T>	synchronizedSet(int initialCapacity)	Constructs a new synchronized Set based on a HashSet with the specified initialCapacity.
static <T> Set<T>	union(Iterable<Set<T>> elements)
static <T> Set<T>	union(Set<T>... elements)
static <T> Set<T>	unionOfListOfLists(Collection<? extends Collection<? extends T>> collectionOfCollection)
static <T> Collection<? extends T>	unmodifiableCollection(Collection<? extends T> c)
static <T> List<? extends T>	unmodifiableList(List<? extends T> l)
static <K,V> Map<? extends K,? extends V>	unmodifiableMap(Map<? extends K,? extends V> m)
static <T> Set<? extends T>	unmodifiableSet(Set<? extends T> s)

Methods inherited from class java.lang.Object

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

Method Detail

map

@SafeVarargs
public static <K,V> Map<K,V> map(Map.Entry<K,V>... entries)

Type Parameters:

K - the key type

V - the value type

Parameters:

entries - the final set of entries to add to the newly created unmodifiable map

Returns:

an unmodifiable map with all given entries

set

@SafeVarargs
public static <T> Set<T> set(T... elements)

Type Parameters:

T - the element type

Parameters:

elements - the elements

Returns:

an UNMODIFIABLE Set<T>

list

@SafeVarargs
public static <T> List<T> list(T... elements)

Type Parameters:

T - the element type

Parameters:

elements - the elements

Returns:

an UNMODIFIABLE List<T>

union

@SafeVarargs
public static <T> Set<T> union(Set<T>... elements)

union

public static <T> Set<T> union(Iterable<Set<T>> elements)

intersection

@SafeVarargs
public static <T> Set<T> intersection(Set<T>... elements)

intersection

public static <T> Set<T> intersection(Iterable<Set<T>> sets)

unmodifiableSet

public static <T> Set<? extends T> unmodifiableSet(Set<? extends T> s)

Type Parameters:

T - the element type

Parameters:

s - the set

Returns:

an UNMODIFIABLE Set<T>

unmodifiableMap

public static <K,V> Map<? extends K,? extends V> unmodifiableMap(Map<? extends K,? extends V> m)

Type Parameters:

K - the key type

V - the value type

Parameters:

m - the map

Returns:

an UNMODIFIABLE Map<K, V>

unmodifiableCollection

public static <T> Collection<? extends T> unmodifiableCollection(Collection<? extends T> c)

Type Parameters:

T - the element type

Parameters:

c - the collection

Returns:

an UNMODIFIABLE Collection<T>

unmodifiableList

public static <T> List<? extends T> unmodifiableList(List<? extends T> l)

Type Parameters:

T - the element type

Parameters:

l - the list

Returns:

an UNMODIFIABLE List<T>

conjunctCollections

public static <T> List<T> conjunctCollections(Collection<T> list1,
                                              Collection<T> list2)

conjunctCollectionsToSet

public static <T> Set<T> conjunctCollectionsToSet(Collection<T> list1,
                                                  Collection<T> list2)

synchronizedInitialSizeMapWithLoadFactor1

public static <K,V> Map<K,V> synchronizedInitialSizeMapWithLoadFactor1(int capacity)

synchronizedMap

public static <K,V> Map<K,V> synchronizedMap()

synchronizedMap

public static <K,V> Map<K,V> synchronizedMap(int initialCapacity)

synchronizedMap

public static <K,V> Map<K,V> synchronizedMap(int initialCapacity,
                                                         float loadFactor)

synchronizedSet

public static <T> Set<T> synchronizedSet()

Constructs a new synchronized Set based on a HashSet.

Type Parameters:

T - the element type

Returns:

a synchronized Set

synchronizedSet

public static <T> Set<T> synchronizedSet(int initialCapacity)

Constructs a new synchronized Set based on a HashSet with the specified initialCapacity.

Type Parameters:

T - the element type

Parameters:

initialCapacity - the initial capacity of the set

Returns:

a synchronized Set

synchronizedList

public static <E> List<E> synchronizedList()

Constructs a new synchronized List based on a LinkedList.

Type Parameters:

E - the element type

Returns:

a synchronized List

synchronizedList

public static <E> List<E> synchronizedList(int initialCapacity)

Constructs a new synchronized List based on a ArrayList with the specified initialCapacity.

Type Parameters:

E - the element type

Parameters:

initialCapacity - the initial capacity of the array list

Returns:

a synchronized List

unionOfListOfLists

public static <T> Set<T> unionOfListOfLists(Collection<? extends Collection<? extends T>> collectionOfCollection)

Type Parameters:

T - the element type

Parameters:

collectionOfCollection - a Collection<Collection<T>>

Returns:

a Set<T> containing all values of all Collections<T> without any duplicates

isNotEmpty

public static <T> boolean isNotEmpty(Collection<T> collection)

Check if collection is not null and not empty

Type Parameters:

T - the element type

Parameters:

collection - Collection to check

Returns:

empty or not

isNotEmpty

public static <K,V> boolean isNotEmpty(Map<K,V> map)

Check if collection is not null and not empty

Type Parameters:

K - the key type

V - the value type

Parameters:

map - Map to check

Returns:

false, if map is null or empty, else true.

isEmptyOrNull

public static <T> boolean isEmptyOrNull(Collection<T> collection)

isEmpty

public static <T> boolean isEmpty(Collection<T> collection)

Check if collection is not null and empty

Type Parameters:

T - the element type

Parameters:

collection - Collection to check

Returns:

true, if collection is not null and empty, else false

isEmpty

public static <K,V> boolean isEmpty(Map<K,V> map)

Check if map is not null and empty

Type Parameters:

K - the key type

V - the value type

Parameters:

map - map to check

Returns:

true, if map is not null and empty, else false

reverse

public static <K,V> Map<V,K> reverse(Map<K,V> map)

Reverses a map (switches key and value types).

Type Parameters:

K - the key type

V - the value type

Parameters:

map - the map

Returns:

the reversed map

nullEmptyOrContainsOnlyNulls

public static boolean nullEmptyOrContainsOnlyNulls(Collection<? extends Object> collection)

Examine a collection and determines if it is null, empty, or contains only null values

Parameters:

collection - Collection to examine

Returns:

whether the collection is null, empty, or contains only nulls

isNotNullOrEmpty

public static boolean isNotNullOrEmpty(Object[] array)

Check if array is not null and not empty

Parameters:

array - Array to check

Returns:

true, if array is not null and not empty

isNullOrEmpty

public static boolean isNullOrEmpty(Object[] array)

Check if array is not null or not empty

Parameters:

array - Array to check

Returns:

true, if array is null or empty

collectionToString

public static String collectionToString(Collection<?> collection)

addToCollectionMap

public static <K,V> void addToCollectionMap(K key,
                                                  V valueToAdd,
                                                  Map<K,Collection<V>> map)

Add a value to a map collection, initializing the key's collection if needed

Type Parameters:

K - the key type

V - the value type

Parameters:

key - Key whose value collection should be added to

valueToAdd - Vale to add to the key's collection

map - Map holding collections

sortByValue

public static <K,V extends Comparable<? super V>> Map<K,V> sortByValue(Map<K,V> map)

csvStringToList

public static List<String> csvStringToList(String csv)

Parse CSV string to List

Parameters:

csv - CSV string

Returns:

List with separated values

svStringToList

public static List<String> svStringToList(String sv,
                                          String separator)

Parse separated value string to List

Parameters:

sv - Separated value string

separator - Separator character

Returns:

List with separated values

csvStringToSet

public static Set<String> csvStringToSet(String csv)

Parse CSV string to Set

Parameters:

csv - CSV string

Returns:

Set with separated values

svStringToSet

public static Set<String> svStringToSet(String sv,
                                        String separator)

Parse separated value string to Set

Parameters:

sv - Separated value string

separator - Seperator character

Returns:

Set with separated values

svStringToArray

public static String[] svStringToArray(String sv,
                                       String separator)

Parse separated value string to array with trimmed values

Parameters:

sv - Separated value string

separator - Separator character

Returns:

Array with separated values

newSortedSet

public static <T extends Comparable<? super T>> SortedSet<T> newSortedSet(Collection<? extends T> set)