CollectionUtils (WebLaF core library 1.2.13 API)

java.lang.Object
- com.alee.utils.CollectionUtils

```
public final class CollectionUtils
extends Object
```
This class provides a set of utilities to work with Collection implementations.

Author:

Mikle Garin

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static boolean`	`addUnique(Collection<Boolean> collection, boolean[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Byte> collection, byte[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Character> collection, char[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Double> collection, double[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Float> collection, float[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Integer> collection, int[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Long> collection, long[] objects)` Adds all objects into the specified list.
`static boolean`	`addUnique(Collection<Short> collection, short[] objects)` Adds all objects into the specified list.
`static <T> boolean`	`addUnique(Collection<T> collection, Collection<T> objects)` Adds all objects into the specified list.
`static <T> boolean`	`addUnique(Collection<T> collection, T... objects)` Adds all objects into the specified list.
`static <T> boolean`	`addUniqueNonNull(Collection<T> collection, Collection<T> objects)` Adds all non-null objects into the specified list.
`static <T> boolean`	`addUniqueNonNull(Collection<T> collection, T... objects)` Adds all non-null objects into the specified list.
`static <T> boolean`	`areAllUnique(Collection<T> collection)` Returns whether or not all `Collection` elements are unique.
`static <T> HashSet<T>`	`asHashSet(Collection<T> data)` Returns data converted into `HashSet`.
`static <T> HashSet<T>`	`asHashSet(T... data)` Returns data converted into `HashSet`.
`static ArrayList<Boolean>`	`asList(boolean[] data)` Returns booleans converted into list.
`static ArrayList<Byte>`	`asList(byte[] data)` Returns bytes converted into list.
`static ArrayList<Character>`	`asList(char[] data)` Returns characters converted into list.
`static ArrayList<Double>`	`asList(double[] data)` Returns doubles converted into list.
`static ArrayList<Float>`	`asList(float[] data)` Returns floats converted into list.
`static ArrayList<Integer>`	`asList(int[] data)` Returns integers converted into list.
`static <T> ArrayList<T>`	`asList(Iterator<T> data)` Returns data converted into list.
`static ArrayList<Long>`	`asList(long[] data)` Returns longs converted into list.
`static ArrayList<Short>`	`asList(short[] data)` Returns shorts converted into list.
`static <T> ArrayList<T>`	`asList(T... data)` Returns data converted into list.
`static <T> ArrayList<T>`	`asNonNullList(T... data)` Returns non-null data converted into list.
`static <T> Vector<T>`	`asVector(T... data)` Returns a vector of objects converted from data.
`static <T> ArrayList<T>`	`copy(Collection<T> collection)` Returns `ArrayList` that is a copy of the specified `Collection`.
`static <T> ArrayList<T>`	`copySubList(List<T> list, int fromIndex, int toIndex)` Returns sub list with copied values.
`static <T> List<T>`	`distinct(List<T> list)` Removes non-distinct `List` elements.
`static boolean`	`equals(Collection collection1, Collection collection2)` Returns whether `Collection`s are equal or not.
`static boolean`	`equals(List list1, List list2, boolean strictIndices)` Returns whether `List`s are equal or not.
`static <T> List<T>`	`fillList(int size, Function<Integer,T> indexMapper)` Returns `List` filled with data provided by index mapping `Function`.
`static <T> ArrayList<T>`	`filter(Collection<T> collection, Filter<T>... filters)` Returns list of elements filtered from collection.
`static <T> ArrayList<T>`	`filter(Collection<T> collection, Filter<T> filter)` Returns list of elements filtered from collection.
`static List<Integer>`	`intRange(int from, int to)` Returns new `List` filled with `Integer`s in the specified range.
`static boolean`	`isEmpty(Collection collection)` Returns whether specified `Collection` is empty or not.
`static <T> ArrayList<T>`	`join(Collection<T>... collections)` Returns collection that contains elements from all specified collections.
`static <K,V> ArrayList<K>`	`keysList(Map<K,V> map)` Returns map keys list.
`static <T> List<T>`	`limit(List<T> list, int limit)` Returns list with limited amount of objects from the initial list.
`static <T> T`	`max(Collection<T> collection, Comparator<T> comparator)` Returns maximum element of the `Collection` according to `Comparator`.
`static <T> List<T>`	`nonNull(List<T> list)` Returns non-`null` `List` that is either specified `list` or new empty `ArrayList`.
`static <T> ArrayList<T>`	`nonNullCopy(Collection<T> collection)` Returns non-`null` `ArrayList` that is a copy of the specified `Collection`.
`static boolean`	`notEmpty(Collection collection)` Returns whether specified `Collection` is empty or not.
`static <T> boolean`	`removeAll(Collection<T> collection, Collection<T> objects)` Removes all objects from the specified list.
`static <T> boolean`	`removeAll(Collection<T> collection, T... objects)` Removes all objects from the specified list.
`static <T> List<T>`	`removeNulls(List<T> list)` Removes all null elements from list.
`static <T extends Collection<?>> T`	`requireNotEmpty(T collection, Supplier<RuntimeException> exceptionSupplier)` Checks that the specified `Collection` is not empty and throws a customized `RuntimeException` if it is.
`static <T> T`	`roundRobin(int index, List<T> items)` Returns item from the `List` at the specified index.
`static <T> List<T>`	`sort(List<T> list, Comparator<T>... comparators)` Sorts `List` using the specified `Comparator`s.
`static <T> List<T>`	`sort(List<T> list, Comparator<T> comparator)` Sorts `List` using the specified `Comparator`.
`static int[]`	`toIntArray(Collection<Integer> collection)` Returns an `int[]` array created using `Collection` of `Integer`s.
`static <T> ArrayList<T>`	`toList(Collection<T> collection)` Returns `List` of objects converted from `Collection`.
`static <T> ArrayList<T>`	`toList(T[] array)` Returns `List` of `Object`s converted from array.
`static Object[]`	`toObjectArray(Collection collection)` Returns an `Object[]` array created using `Collection` of `Object`s.
`static <T> ArrayList<String>`	`toStringList(List<T> list, Function<T,String> textProvider)` Returns `List` of `String`s extracted from the specified elements `List`.
`static <T> Vector<T>`	`toVector(Collection<T> collection)` Returns a vector of objects converted from collection.
`static <K,V> ArrayList<V>`	`valuesList(Map<K,V> map)` Returns map values list.
`static <K,V> ArrayList<V>`	`valuesSummaryList(Map<K,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

Method Detail

isEmpty
```
public static boolean isEmpty(@Nullable
                              Collection collection)
```
Returns whether specified Collection is empty or not.

Parameters:

collection - Collection to process

Returns:

true if specified Collection is empty, false otherwise

notEmpty
```
public static boolean notEmpty(@Nullable
                               Collection collection)
```
Returns whether specified Collection is empty or not.

Parameters:

collection - Collection to process

Returns:

true if specified Collection is not empty, false otherwise

nonNull
```
@NotNull
public static <T> List<T> nonNull(@Nullable
                                           List<T> list)
```
Returns non-null List that is either specified list or new empty ArrayList.

Type Parameters:

T - elements type

Parameters:

list - List

Returns:

non-null List that is either specified list or new empty ArrayList

limit
```
@NotNull
public static <T> List<T> limit(@NotNull
                                         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

max

@Nullable
public static <T> T max(@Nullable
                                  Collection<T> collection,
                                  @NotNull
                                  Comparator<T> comparator)

Returns maximum element of the Collection according to Comparator. This methid is slightly more optimal and safe unlike Collections.max(Collection, Comparator).

Type Parameters:: T - collection element type
Parameters:: collection - Collection; comparator - Comparator
Returns:: maximum element of the Collection according to Comparator

copySubList

@NotNull
public static <T> ArrayList<T> copySubList(@NotNull
                                                    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

@NotNull
public static ArrayList<Boolean> asList(@NotNull
                                                 boolean[] data)

Returns booleans converted into list.

Parameters:: data - booleans array
Returns:: booleans list

asList

@NotNull
public static ArrayList<Integer> asList(@NotNull
                                                 int[] data)

Returns integers converted into list.

Parameters:: data - integers array
Returns:: integers list

asList

@NotNull
public static ArrayList<Character> asList(@NotNull
                                                   char[] data)

Returns characters converted into list.

Parameters:: data - characters array
Returns:: characters list

asList

@NotNull
public static ArrayList<Byte> asList(@NotNull
                                              byte[] data)

Returns bytes converted into list.

Parameters:: data - bytes array
Returns:: bytes list

asList

@NotNull
public static ArrayList<Short> asList(@NotNull
                                               short[] data)

Returns shorts converted into list.

Parameters:: data - shorts array
Returns:: shorts list

asList

@NotNull
public static ArrayList<Long> asList(@NotNull
                                              long[] data)

Returns longs converted into list.

Parameters:: data - longs array
Returns:: longs list

asList

@NotNull
public static ArrayList<Float> asList(@NotNull
                                               float[] data)

Returns floats converted into list.

Parameters:: data - floats array
Returns:: floats list

asList

@NotNull
public static ArrayList<Double> asList(@NotNull
                                                double[] data)

Returns doubles converted into list.

Parameters:: data - doubles array
Returns:: doubles list

asList

@NotNull
public static <T> ArrayList<T> asList(@NotNull
                                               T... data)

Returns data converted into list.

Type Parameters:: T - data type
Parameters:: data - data
Returns:: data list

asList

@NotNull
public static <T> ArrayList<T> asList(@NotNull
                                               Iterator<T> data)

Returns data converted into list.

Type Parameters:: T - data type
Parameters:: data - data
Returns:: data list

asNonNullList

@NotNull
public static <T> ArrayList<T> asNonNullList(@NotNull
                                                      T... data)

Returns non-null data converted into list.

Type Parameters:: T - data type
Parameters:: data - data
Returns:: non-null data list

areAllUnique
```
public static <T> boolean areAllUnique(@NotNull
                                       Collection<T> collection)
```
Returns whether or not all Collection elements are unique.

Type Parameters:

T - Collection element type

Parameters:

collection - Collection

Returns:

true if all Collection elements are unique, false otherwise