com.alee.utils

Class CollectionUtils

java.lang.Object

com.alee.utils.CollectionUtils

public final class CollectionUtils
extends java.lang.Object

This class provides a set of utilities to work with collections.

Constructor Summary

Constructors

Constructor and Description
CollectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T> boolean	addAll(java.util.Collection<T> collection, java.util.Collection<T> objects) Adds all objects into the specified list.
static <T> boolean	addAll(java.util.Collection<T> collection, T... objects) Adds all objects into the specified list.
static <T> boolean	addAllNonNull(java.util.Collection<T> collection, java.util.Collection<T> objects) Adds all non-null objects into the specified list.
static <T> boolean	addAllNonNull(java.util.Collection<T> collection, T... objects) Adds all non-null objects into the specified list.
static <T> java.util.ArrayList<T>	asList(java.util.Iterator<T> data) Returns data converted into list.
static <T> java.util.ArrayList<T>	asList(T... data) Returns data converted into list.
static <T> java.util.ArrayList<T>	asNonNullList(T... data) Returns non-null data converted into list.
static <T> java.util.ArrayList<T>	copy(java.util.Collection<T> collection) Returns copy of the specified list.
static <T> java.util.ArrayList<T>	copySubList(java.util.List<T> list, int fromIndex, int toIndex) Returns sub list with copied values.
static boolean	equals(java.util.List list1, java.util.List list2) Returns whether lists are equal or not.
static <T> java.util.List<T>	fillList(int amount, IndexedSupplier<T> supplier) Fills and returns list with data provided by supplier interface implementation.
static <T> java.util.ArrayList<T>	filter(java.util.Collection<T> collection, Filter<T> filter) Returns list of elements filtered from collection.
static boolean	isEmpty(java.util.Collection collection) Returns whether specified collection is empty or not.
static <T> java.util.ArrayList<T>	join(java.util.Collection<T>... collections) Returns collection that contains elements from all specified collections.
static <K,V> java.util.ArrayList<K>	keysList(java.util.Map<K,V> map) Returns map keys list.
static <T> java.util.List<T>	limit(java.util.List<T> list, int limit) Returns list with limited amount of objects from the initial list.
static <T> boolean	removeAll(java.util.Collection<T> collection, T... objects) Removes all objects from the specified list.
static <T> java.util.List<T>	removeNulls(java.util.List<T> list) Removes all null elements from list.
static int[]	toArray(java.util.List<java.lang.Integer> list) Returns an int array created using Integer list.
static <T> java.util.ArrayList<T>	toList(java.util.Deque<T> deque) Returns a list of objects converted from deque.
static <T> java.util.ArrayList<T>	toList(T[] array) Returns a list of objects converted from array.
static <T> java.util.ArrayList<java.lang.String>	toStringList(java.util.List<T> list, TextProvider<T> textProvider) Returns list of strings extracted from the specified elements list.
static <T> java.util.Vector<T>	toVector(java.util.Collection<T> collection) Returns a vector of objects converted from collection.
static <K,V> java.util.ArrayList<V>	valuesList(java.util.Map<K,V> map) Returns map values list.
static <K,V> java.util.ArrayList<V>	valuesSummaryList(java.util.Map<K,java.util.List<V>> map) Returns map values summary list with unique elements only.

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionUtils

public CollectionUtils()

Method Detail

isEmpty

public static boolean isEmpty(java.util.Collection collection)

Returns whether specified collection is empty or not.

Parameters:

collection - collection to process

Returns:

true if specified collection is empty, false otherwise

limit

public static <T> java.util.List<T> limit(java.util.List<T> list,
                                          int limit)

Returns list with limited amount of objects from the initial list. Only specified amount of first objects in initial list will be transferred to new list.

Type Parameters:

T - object type

Parameters:

list - initial list

limit - objects amount limitation

Returns:

list with limited amount of objects from the initial list

copySubList

public static <T> java.util.ArrayList<T> copySubList(java.util.List<T> list,
                                                     int fromIndex,
                                                     int toIndex)

Returns sub list with copied values.

Type Parameters:

T - data type

Parameters:

list - source list

fromIndex - start index

toIndex - end index

Returns:

sub list with copied values

asList

public static <T> java.util.ArrayList<T> asList(T... data)

Returns data converted into list.

Type Parameters:

T - data type

Parameters:

data - data

Returns:

data list

asList

public static <T> java.util.ArrayList<T> asList(java.util.Iterator<T> data)

Returns data converted into list.

Type Parameters:

T - data type

Parameters:

data - data

Returns:

data list

asNonNullList

public static <T> java.util.ArrayList<T> asNonNullList(T... data)

Returns non-null data converted into list.

Type Parameters:

T - data type

Parameters:

data - data

Returns:

non-null data list

addAll

public static <T> boolean addAll(java.util.Collection<T> collection,
                                 T... objects)

Adds all objects into the specified list.

Type Parameters:

T - objects type

Parameters:

collection - list to fill

objects - objects

Returns:

true if list changed as the result of this operation, false otherwise

addAllNonNull

public static <T> boolean addAllNonNull(java.util.Collection<T> collection,
                                        T... objects)

Adds all non-null objects into the specified list.

Type Parameters:

T - objects type

Parameters:

collection - list to fill

objects - objects

Returns:

true if list changed as the result of this operation, false otherwise

addAll

public static <T> boolean addAll(java.util.Collection<T> collection,
                                 java.util.Collection<T> objects)

Adds all objects into the specified list.

Type Parameters:

T - objects type

Parameters:

collection - list to fill

objects - objects

Returns:

true if list changed as the result of this operation, false otherwise

addAllNonNull

public static <T> boolean addAllNonNull(java.util.Collection<T> collection,
                                        java.util.Collection<T> objects)

Adds all non-null objects into the specified list.

Type Parameters:

T - objects type

Parameters:

collection - list to fill

objects - objects

Returns:

true if list changed as the result of this operation, false otherwise

removeAll

public static <T> boolean removeAll(java.util.Collection<T> collection,
                                    T... objects)

Removes all objects from the specified list.

Type Parameters:

T - objects type

Parameters:

collection - list to fill

objects - objects

Returns:

true if list changed as the result of this operation, false otherwise

join

public static <T> java.util.ArrayList<T> join(java.util.Collection<T>... collections)

Returns collection that contains elements from all specified collections. Order in which collection are provided will be preserved.

Type Parameters:

T - collection type

Parameters:

collections - collections to join

Returns:

collection that contains elements from all specified collections

copy

public static <T> java.util.ArrayList<T> copy(java.util.Collection<T> collection)

Returns copy of the specified list. Note that this method will copy same list values into the new list.

Type Parameters:

T - list type

Parameters:

collection - list to copy

Returns:

copy of the specified list

removeNulls

public static <T> java.util.List<T> removeNulls(java.util.List<T> list)

Removes all null elements from list.

Type Parameters:

T - list type

Parameters:

list - list to refactor

Returns:

refactored list

equals

public static boolean equals(java.util.List list1,
                             java.util.List list2)

Returns whether lists are equal or not.

Parameters:

list1 - first list

list2 - second list

Returns:

true if lists are equal, false otherwise

toStringList

public static <T> java.util.ArrayList<java.lang.String> toStringList(java.util.List<T> list,
                                                                     TextProvider<T> textProvider)

Returns list of strings extracted from the specified elements list.

Type Parameters:

T - elements type

Parameters:

list - elements list

textProvider - text provider

Returns:

list of strings extracted from the specified elements list

toArray

public static int[] toArray(java.util.List<java.lang.Integer> list)

Returns an int array created using Integer list.

Parameters:

list - Integer list

Returns:

int array

toList

public static <T> java.util.ArrayList<T> toList(T[] array)

Returns a list of objects converted from array.

Type Parameters:

T - data type

Parameters:

array - data array

Returns:

data list

toList

public static <T> java.util.ArrayList<T> toList(java.util.Deque<T> deque)

Returns a list of objects converted from deque.

Type Parameters:

T - data type

Parameters:

deque - data deque

Returns:

data list

toVector

public static <T> java.util.Vector<T> toVector(java.util.Collection<T> collection)

Returns a vector of objects converted from collection.

Type Parameters:

T - data type

Parameters:

collection - data collection

Returns:

a vector of objects converted from collection

filter

public static <T> java.util.ArrayList<T> filter(java.util.Collection<T> collection,
                                                Filter<T> filter)

Returns list of elements filtered from collection.

Type Parameters:

T - elements type

Parameters:

collection - collection to filter

filter - filter to process

Returns:

list of elements filtered from collection

keysList

public static <K,V> java.util.ArrayList<K> keysList(java.util.Map<K,V> map)

Returns map keys list.

Type Parameters:

K - key object type

V - value object type

Parameters:

map - map to process

Returns:

map keys list

valuesList

public static <K,V> java.util.ArrayList<V> valuesList(java.util.Map<K,V> map)

Returns map values list.

Type Parameters:

K - key object type

V - value object type

Parameters:

map - map to process

Returns:

map values list

valuesSummaryList

public static <K,V> java.util.ArrayList<V> valuesSummaryList(java.util.Map<K,java.util.List<V>> map)

Returns map values summary list with unique elements only.

Type Parameters:

K - key object type

V - value object type

Parameters:

map - map to process

Returns:

map values summary list with unique elements only

fillList

public static <T> java.util.List<T> fillList(int amount,
                                             IndexedSupplier<T> supplier)

Fills and returns list with data provided by supplier interface implementation.

Type Parameters:

T - data type

Parameters:

amount - amount of list elements

supplier - data provider

Returns:

list filled with data provided by supplier interface implementation