CollectionHelper (Cyclos 4.8.3 WS API Documentation)

java.lang.Object
- org.cyclos.utils.CollectionHelper

public class CollectionHelper
extends java.lang.Object

Helper methods for collections

Author:: luis

Constructor Summary

Constructors
Constructor and Description

CollectionHelper()

Constructors
Constructor and Description
`CollectionHelper()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static <T> void`	`addOrRemove(java.util.Collection<T> collection, T value, boolean add)` Adds or removes a value from the given collection, according to the given flag (true = add, false = remove)
`static <T> Page<T>`	`asPage(java.lang.Iterable<T> collection)` Returns a new `Page` containing a copy of the given `Collection` as the total elements
`static <T> Page<T>`	`asPage(java.util.List<T> all, int pageSize, int currentPage)` Applies the pagination to an in-memory list
`static <T> Page<T>`	`asPage(T... elements)` Returns a new `Page` containing a copy of the given `Collection` as the total elements
`static <T> java.util.Set<T>`	`asSet(java.util.List<T> list)` Returns the given list as a Set
`static <T> java.util.Set<T>`	`asSet(T... elements)` Returns the given elements as a Set
`static <T> java.util.stream.Stream<T>`	`asStream(java.lang.Iterable<T> iterable)` Returns a `Stream` equivalent to the given `Iterable`
`static <T> java.util.stream.Stream<T>`	`asStream(java.util.Iterator<T> iterator)` Returns a `Stream` equivalent to the given iterator
`static <T> java.util.stream.Stream<T>`	`asStream(T[] array)` Returns a `Stream` equivalent to the given array
`static <T> boolean`	`containsAll(java.util.Collection<T> first, java.util.Collection<T> second)`
`static boolean`	`containsAny(java.util.Collection<?> collection, java.util.Collection<?> toTest)` Checks whether the first collection contains at least one element of the second collection
`static boolean`	`containsAny(java.util.Collection<?> collection, java.lang.Object... toTest)` Checks whether the first collection contains at least one element of the second collection
`static boolean`	`equals(java.util.Map<?,?> map1, java.util.Map<?,?> map2)` Returns whether all keys and values are equals on both maps.
`static <I,O extends I> java.util.stream.Stream<O>`	`filterByType(java.util.stream.Stream<I> stream, java.lang.Class<O> subType)` Returns a filtered `Stream` containing only the elements which are instances of the given subclass
`static <T> T`	`first(java.lang.Iterable<T> collection)` Returns the first element in a collection, or null when the collection is empty or null
`static <T> T`	`first(T[] value)` Returns the first element in an array, or null if the array is null or empty
`static java.lang.Object[]`	`flatten(java.lang.Object... input)` Returns an array comprised of all elements of all objects in the given input.
`static <K,V> V`	`getOrSupply(java.util.Map<K,V> map, K key, java.util.function.Supplier<V> supplier)` Returns the given key from the Map.
`static java.lang.Integer`	`getTotalCount(java.lang.Iterable<?> collection)` Returns the total count of the given collection, handling pages with the `Page.getTotalCount()` method.
`static int`	`hashCode(java.util.Map<?,?> map)` Returns the hashCode of the given Map, by hashing each key and value
`static boolean`	`hasOnlyOneElement(java.util.Collection<?> collection)` Returns true if the collection has only one element, handling nulls.
`static boolean`	`isEmpty(java.lang.Iterable<?> collection)` Checks whether the given collection is null or empty
`static boolean`	`isEmpty(java.util.Map<?,?> map)` Checks whether the given map is null or empty
`static boolean`	`isEmpty(java.lang.Object[] array)` Checks whether the given array is null or empty
`static boolean`	`isNotEmpty(java.lang.Iterable<?> collection)` Checks whether the given collection is not null and not empty
`static boolean`	`isNotEmpty(java.util.Map<?,?> map)` Checks whether the given map is not null and not empty
`static boolean`	`isNotEmpty(java.lang.Object[] array)` Checks whether the given array is not null and not empty
`static <T> java.lang.Iterable<T>`	`iterable(java.util.Enumeration<T> enumeration)` Returns an `Iterable` for the given enumeration
`static <T> java.lang.Iterable<T>`	`iterable(java.util.Iterator<T> iterator)` Returns an `Iterable` which returns the given iterator.
`static java.lang.String`	`join(java.lang.Iterable<?> collection, java.lang.String separator)` Joins a collection of values into a single string, using the given separator.
`static java.lang.String`	`join(java.lang.Object[] array, java.lang.String separator)` Joins an array of values into a single string, using the given separator.
`static int`	`length(java.lang.Object[] array)` It returns the array's length supporting null values (returning 0).
`static <T> java.util.Collection<T>`	`orEmpty(java.util.Collection<T> collection)` Returns an empty list if the given list is null
`static <T> java.util.List<T>`	`orEmpty(java.util.List<T> list)` Returns an empty list if the given list is null
`static <K,V> java.util.Map<K,V>`	`orEmpty(java.util.Map<K,V> map)` Returns an empty map if the given map is null
`static <T> java.util.Set<T>`	`orEmpty(java.util.Set<T> set)` Returns an empty set if the given set is null
`static <T> T`	`random(java.util.List<T> list)` Returns a random item from a collection, handling nulls
`static void`	`removeNulls(java.util.Collection<?> collection)` Removes any null elements on the given collection
`static int`	`size(java.util.Collection<?> collection)` Returns the collection size, handling nulls (returns 0 if the collection is null)
`static int`	`size(java.lang.Object[] array)` Returns the size of the given array, or 0 if null
`static <T extends java.lang.Comparable<? super T>> java.util.List<T>`	`sort(java.util.Collection<T> collection)` It sorts the specified collection returning an ordered List. If the collection already is a list it return the same instance.
`static <T> java.util.List<T>`	`sort(java.util.Collection<T> collection, java.util.Comparator<? super T> comparator)` It sorts the specified collection returning an ordered List. If the collection already is a list it return the same instance.
`static <T> java.util.List<java.util.List<T>>`	`split(java.util.List<T> list, int maxSize)` Splits the given list into several sub lists, with the given maximum size
`static <T> java.util.Iterator<T>`	`toIterator(java.util.Enumeration<T> enumeration)` Returns an iterator with the same elements as the given enumeration

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CollectionHelper
```
public CollectionHelper()
```
- Method Detail
  - addOrRemove
```
public static <T> void addOrRemove(java.util.Collection<T> collection,
                                   T value,
                                   boolean add)
```
    Adds or removes a value from the given collection, according to the given flag (true = add, false = remove)
  - asPage
```
public static <T> Page<T> asPage(java.lang.Iterable<T> collection)
```
    Returns a new Page containing a copy of the given Collection as the total elements
  - asPage
```
public static <T> Page<T> asPage(java.util.List<T> all,
                                 int pageSize,
                                 int currentPage)
```
    Applies the pagination to an in-memory list
  - asPage
```
@SafeVarargs
public static <T> Page<T> asPage(T... elements)
```
    Returns a new Page containing a copy of the given Collection as the total elements
  - asSet
```
public static <T> java.util.Set<T> asSet(java.util.List<T> list)
```
    Returns the given list as a Set
  - asSet
```
@SafeVarargs
public static <T> java.util.Set<T> asSet(T... elements)
```
    Returns the given elements as a Set
  - asStream
```
public static <T> java.util.stream.Stream<T> asStream(java.lang.Iterable<T> iterable)
```
    Returns a Stream equivalent to the given Iterable
  - asStream
```
public static <T> java.util.stream.Stream<T> asStream(java.util.Iterator<T> iterator)
```
    Returns a Stream equivalent to the given iterator
  - asStream
```
public static <T> java.util.stream.Stream<T> asStream(T[] array)
```
    Returns a Stream equivalent to the given array
  - containsAll
```
public static <T> boolean containsAll(java.util.Collection<T> first,
                                      java.util.Collection<T> second)
```
    Parameters:
    
    first - the container collection or null
    
    second - the contained collection or null
    
    Returns:
    
    true if the first collection contains all elements of the second one.
    If first is empty/null then it returns true only if second is empty/null too.
    Otherwise it returns true if second is empty/null or first contains all elements of second.
  - containsAny
```
public static boolean containsAny(java.util.Collection<?> collection,
                                  java.util.Collection<?> toTest)
```
    Checks whether the first collection contains at least one element of the second collection
  - containsAny
```
public static boolean containsAny(java.util.Collection<?> collection,
                                  java.lang.Object... toTest)
```
    Checks whether the first collection contains at least one element of the second collection
  - equals
```
public static boolean equals(java.util.Map<?,?> map1,
                             java.util.Map<?,?> map2)
```
    Returns whether all keys and values are equals on both maps. Also returns true if both maps are null of if their equals() method return true
  - filterByType
```
public static <I,O extends I> java.util.stream.Stream<O> filterByType(java.util.stream.Stream<I> stream,
                                                                      java.lang.Class<O> subType)
```
    Returns a filtered Stream containing only the elements which are instances of the given subclass
  - first
```
public static <T> T first(java.lang.Iterable<T> collection)
```
    Returns the first element in a collection, or null when the collection is empty or null
  - first
```
public static <T> T first(T[] value)
```
    Returns the first element in an array, or null if the array is null or empty
  - flatten
```
public static java.lang.Object[] flatten(java.lang.Object... input)
```
    Returns an array comprised of all elements of all objects in the given input. If each input is:
    - An Iterable: Add each element returned by Iterable.iterator()
    - An Object[]: Add each array element
    - null: Ignore
    - Anything else: Add the object as is
    This method is not recursive. If there are nested lists of objects, they are kept as they are.
  - getOrSupply
```
public static <K,V> V getOrSupply(java.util.Map<K,V> map,
                                  K key,
                                  java.util.function.Supplier<V> supplier)
```
    Returns the given key from the Map. If there is no current value associated with the key, calls the supplier and put its result in the map. The whole operation is synchronized using the given map as monitor.
  - getTotalCount
```
public static java.lang.Integer getTotalCount(java.lang.Iterable<?> collection)
```
    Returns the total count of the given collection, handling pages with the Page.getTotalCount() method. If the collection is a Page and the configuration is set to skip total count, this method returns null.
  - hashCode
```
public static int hashCode(java.util.Map<?,?> map)
```
    Returns the hashCode of the given Map, by hashing each key and value
  - hasOnlyOneElement
```
public static boolean hasOnlyOneElement(java.util.Collection<?> collection)
```
    Returns true if the collection has only one element, handling nulls.
    
    See Also:
    
    #size(Iterable)
  - isEmpty
```
public static boolean isEmpty(java.lang.Iterable<?> collection)
```
    Checks whether the given collection is null or empty
  - isEmpty
```
public static boolean isEmpty(java.util.Map<?,?> map)
```
    Checks whether the given map is null or empty
  - isEmpty
```
public static boolean isEmpty(java.lang.Object[] array)
```
    Checks whether the given array is null or empty
  - isNotEmpty
```
public static boolean isNotEmpty(java.lang.Iterable<?> collection)
```
    Checks whether the given collection is not null and not empty
  - isNotEmpty
```
public static boolean isNotEmpty(java.util.Map<?,?> map)
```
    Checks whether the given map is not null and not empty
  - isNotEmpty
```
public static boolean isNotEmpty(java.lang.Object[] array)
```
    Checks whether the given array is not null and not empty
  - iterable
```
public static <T> java.lang.Iterable<T> iterable(java.util.Enumeration<T> enumeration)
```
    Returns an Iterable for the given enumeration
  - iterable
```
public static <T> java.lang.Iterable<T> iterable(java.util.Iterator<T> iterator)
```
    Returns an Iterable which returns the given iterator. Useful to use iterators in the enhanced for loop
  - join
```
public static java.lang.String join(java.lang.Iterable<?> collection,
                                    java.lang.String separator)
```
    Joins a collection of values into a single string, using the given separator. If the collection is null, returns an empty string. If the separator is null, no separator is used.
  - join
```
public static java.lang.String join(java.lang.Object[] array,
                                    java.lang.String separator)
```
    Joins an array of values into a single string, using the given separator. If the collection is null, returns an empty string. If the separator is null, no separator is used.
  - length
```
public static int length(java.lang.Object[] array)
```
    It returns the array's length supporting null values (returning 0).
  - orEmpty
```
public static <T> java.util.Collection<T> orEmpty(java.util.Collection<T> collection)
```
    Returns an empty list if the given list is null
  - orEmpty
```
public static <T> java.util.List<T> orEmpty(java.util.List<T> list)
```
    Returns an empty list if the given list is null
  - orEmpty
```
public static <K,V> java.util.Map<K,V> orEmpty(java.util.Map<K,V> map)
```
    Returns an empty map if the given map is null
  - orEmpty
```
public static <T> java.util.Set<T> orEmpty(java.util.Set<T> set)
```
    Returns an empty set if the given set is null
  - random
```
public static <T> T random(java.util.List<T> list)
```
    Returns a random item from a collection, handling nulls
  - removeNulls
```
public static void removeNulls(java.util.Collection<?> collection)
```
    Removes any null elements on the given collection
  - size
```
public static int size(java.util.Collection<?> collection)
```
    Returns the collection size, handling nulls (returns 0 if the collection is null)
  - size
```
public static int size(java.lang.Object[] array)
```
    Returns the size of the given array, or 0 if null
  - sort
```
public static <T extends java.lang.Comparable<? super T>> java.util.List<T> sort(java.util.Collection<T> collection)
```
    It sorts the specified collection returning an ordered List.
    If the collection already is a list it return the same instance. Otherwise it creates a new list. If the input collection is null, returns an empty list.
  - sort
```
public static <T> java.util.List<T> sort(java.util.Collection<T> collection,
                                         java.util.Comparator<? super T> comparator)
```
    It sorts the specified collection returning an ordered List.
    If the collection already is a list it return the same instance. Otherwise it creates a new list. If the input collection is null, returns an empty list.
  - split
```
public static <T> java.util.List<java.util.List<T>> split(java.util.List<T> list,
                                                          int maxSize)
```
    Splits the given list into several sub lists, with the given maximum size
  - toIterator
```
public static <T> java.util.Iterator<T> toIterator(java.util.Enumeration<T> enumeration)
```
    Returns an iterator with the same elements as the given enumeration

Class CollectionHelper

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

CollectionHelper

Method Detail

addOrRemove

asPage

asPage

asPage

asSet

asSet

asStream

asStream

asStream

containsAll

containsAny

containsAny

equals

filterByType

first

first

flatten

getOrSupply

getTotalCount

hashCode

hasOnlyOneElement

isEmpty

isEmpty

isEmpty

isNotEmpty

isNotEmpty

isNotEmpty

iterable

iterable

join

join

length

orEmpty

orEmpty

orEmpty

orEmpty

random

removeNulls

size

size

sort

sort

split

toIterator