Class FXCollections

java.lang.Object

javafx.collections.FXCollections

public class FXCollections extends Object

Utility class that consists of static methods that are 1:1 copies of java.util.Collections methods.

The wrapper methods (like synchronizedObservableList or emptyObservableList) has exactly the same functionality as the methods in Collections, with exception that they return ObservableList and are therefore suitable for methods that require ObservableList on input.

The utility methods are here mainly for performance reasons. All methods are optimized in a way that they yield only limited number of notifications. On the other hand, java.util.Collections methods might call "modification methods" on an ObservableList multiple times, resulting in a number of notifications.

Since:: JavaFX 2.0

Method Summary

Modifier and Type	Method	Description
`static <E> ObservableList<E>`	`checkedObservableList(ObservableList<E> list, Class<E> type)`	Creates and returns a typesafe wrapper on top of provided observable list.
`static <K, V> ObservableMap<K,V>`	`checkedObservableMap(ObservableMap<K,V> map, Class<K> keyType, Class<V> valueType)`	Creates and returns a typesafe wrapper on top of provided observable map.
`static <E> ObservableSet<E>`	`checkedObservableSet(ObservableSet<E> set, Class<E> type)`	Creates and returns a typesafe wrapper on top of provided observable set.
`static <E> ObservableList<E>`	`concat(ObservableList<E>... lists)`	Concatenates more observable lists into one.
`static <T> void`	`copy(ObservableList<? super T> dest, List<? extends T> src)`	Copies elements from src to dest.
`static <E> ObservableList<E>`	`emptyObservableList()`	Creates an empty unmodifiable observable list.
`static <K, V> ObservableMap<K,V>`	`emptyObservableMap()`	Creates an empty unmodifiable observable map.
`static <E> ObservableSet<E>`	`emptyObservableSet()`	Creates an empty unmodifiable observable set.
`static <T> void`	`fill(ObservableList<? super T> list, T obj)`	Fills the provided list with obj.
`static <E> ObservableList<E>`	`observableArrayList()`	Creates a new empty observable list that is backed by an array list.
`static <E> ObservableList<E>`	`observableArrayList(E... items)`	Creates a new observable array list with `items` added to it.
`static <E> ObservableList<E>`	`observableArrayList(Collection<? extends E> col)`	Creates a new observable array list and adds a content of collection `col` to it.
`static <E> ObservableList<E>`	`observableArrayList(Callback<E,Observable[]> extractor)`	Creates a new empty `ObservableList` that is backed by an array list and listens to changes in observables of its items.
`static ObservableFloatArray`	`observableFloatArray()`	Creates a new empty observable float array.
`static ObservableFloatArray`	`observableFloatArray(float... values)`	Creates a new observable float array with `values` set to it.
`static ObservableFloatArray`	`observableFloatArray(ObservableFloatArray array)`	Creates a new observable float array with copy of elements in given `array`.
`static <K, V> ObservableMap<K,V>`	`observableHashMap()`	Creates a new empty observable map that is backed by a HashMap.
`static ObservableIntegerArray`	`observableIntegerArray()`	Creates a new empty observable integer array.
`static ObservableIntegerArray`	`observableIntegerArray(int... values)`	Creates a new observable integer array with `values` set to it.
`static ObservableIntegerArray`	`observableIntegerArray(ObservableIntegerArray array)`	Creates a new observable integer array with copy of elements in given `array`.
`static <E> ObservableList<E>`	`observableList(List<E> list)`	Constructs an ObservableList that is backed by the specified list.
`static <E> ObservableList<E>`	`observableList(List<E> list, Callback<E,Observable[]> extractor)`	Constructs an `ObservableList` that is backed by the specified list and listens to changes in observables of its items.
`static <K, V> ObservableMap<K,V>`	`observableMap(Map<K,V> map)`	Constructs an ObservableMap that is backed by the specified map.
`static <E> ObservableSet<E>`	`observableSet(E... elements)`	Constructs an ObservableSet backed by a HashSet that contains all the specified elements.
`static <E> ObservableSet<E>`	`observableSet(Set<E> set)`	Constructs an ObservableSet that is backed by the specified set.
`static <T> boolean`	`replaceAll(ObservableList<T> list, T oldVal, T newVal)`	Replace all oldVal elements in the list with newVal element.
`static void`	`reverse(ObservableList list)`	Reverses the order in the list.
`static void`	`rotate(ObservableList list, int distance)`	Rotates the list by distance.
`static void`	`shuffle(ObservableList<?> list)`	Shuffles all elements in the observable list.
`static void`	`shuffle(ObservableList list, Random rnd)`	Shuffles all elements in the observable list.
`static <E> ObservableList<E>`	`singletonObservableList(E e)`	Creates an unmodifiable observable list with single element.
`static <T extends Comparable<? super T>> void`	`sort(ObservableList<T> list)`	Sorts the provided observable list as specified in `Collections.sort(List)`.
`static <T> void`	`sort(ObservableList<T> list, Comparator<? super T> comparator)`	Sorts the provided observable list as specified in `Collections.sort(List, Comparator)`.
`static <E> ObservableList<E>`	`synchronizedObservableList(ObservableList<E> list)`	Creates and returns a synchronized wrapper on top of provided observable list.
`static <K, V> ObservableMap<K,V>`	`synchronizedObservableMap(ObservableMap<K,V> map)`	Creates and returns a synchronized wrapper on top of provided observable map.
`static <E> ObservableSet<E>`	`synchronizedObservableSet(ObservableSet<E> set)`	Creates and returns a synchronized wrapper on top of provided observable set.
`static <E> ObservableList<E>`	`unmodifiableObservableList(ObservableList<E> list)`	Creates and returns unmodifiable wrapper list on top of provided observable list.
`static <K, V> ObservableMap<K,V>`	`unmodifiableObservableMap(ObservableMap<K,V> map)`	Constructs a read-only interface to the specified ObservableMap.
`static <E> ObservableSet<E>`	`unmodifiableObservableSet(ObservableSet<E> set)`	Creates and returns unmodifiable wrapper on top of provided observable set.

Methods declared in class java.lang.Object

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

Method Details

observableList

public static <E> ObservableList<E> observableList(List<E> list)

Constructs an ObservableList that is backed by the specified list. Mutation operations on the ObservableList instance will be reported to observers that have registered on that instance.
Note that mutation operations made directly to the underlying list are not reported to observers of any ObservableList that wraps it.

Type Parameters:: E - The type of List to be wrapped
Parameters:: list - a concrete List that backs this ObservableList
Returns:: a newly created ObservableList

observableList

public static <E> ObservableList<E> observableList(List<E> list, Callback<E,Observable[]> extractor)

Constructs an ObservableList that is backed by the specified list and listens to changes in observables of its items. Mutation operations made directly to the underlying list are not reported to observers of any ObservableList that wraps it.

The extractor returns observables (usually properties) of the objects in the created list. These observables are listened for changes, and the user is notified of these through an update change of an attached ListChangeListener. These changes are unrelated to the changes made to the observable list itself using methods such as add and remove.

For example, a list of Shapes can listen to changes in the shapes' fill property.

Type Parameters:

E - The type of List to be wrapped

Parameters:

list - a concrete List that backs this ObservableList

extractor - element to Observable[] converter

Returns:

a newly created ObservableList

Since:

JavaFX 2.1

See Also:

observableMap

public static <K, V> ObservableMap<K,V> observableMap(Map<K,V> map)

Constructs an ObservableMap that is backed by the specified map. Mutation operations on the ObservableMap instance will be reported to observers that have registered on that instance.
Note that mutation operations made directly to the underlying map are not reported to observers of any ObservableMap that wraps it.

Type Parameters:: K - the type of the wrapped key; V - the type of the wrapped value
Parameters:: map - a Map that backs this ObservableMap
Returns:: a newly created ObservableMap

observableSet

public static <E> ObservableSet<E> observableSet(Set<E> set)

Constructs an ObservableSet that is backed by the specified set. Mutation operations on the ObservableSet instance will be reported to observers that have registered on that instance.
Note that mutation operations made directly to the underlying set are not reported to observers of any ObservableSet that wraps it.

Type Parameters:: E - The type of List to be wrapped
Parameters:: set - a Set that backs this ObservableSet
Returns:: a newly created ObservableSet
Since:: JavaFX 2.1

observableSet

public static <E> ObservableSet<E> observableSet(E... elements)

Constructs an ObservableSet backed by a HashSet that contains all the specified elements.

Type Parameters:: E - The type of List to be wrapped
Parameters:: elements - elements that will be added into returned ObservableSet
Returns:: a newly created ObservableSet
Since:: JavaFX 2.1

unmodifiableObservableMap

public static <K, V> ObservableMap<K,V> unmodifiableObservableMap(ObservableMap<K,V> map)

Constructs a read-only interface to the specified ObservableMap. Only mutation operations made to the underlying ObservableMap will be reported to observers that have registered on the unmodifiable instance. This allows clients to track changes in a Map but disallows the ability to modify it.

Type Parameters:: K - the type of the wrapped key; V - the type of the wrapped value
Parameters:: map - an ObservableMap that is to be monitored by this interface
Returns:: a newly created UnmodifiableObservableMap

checkedObservableMap

public static <K, V> ObservableMap<K,V> checkedObservableMap(ObservableMap<K,V> map, Class<K> keyType, Class<V> valueType)

Creates and returns a typesafe wrapper on top of provided observable map.

Type Parameters:

K - the type of the wrapped key

V - the type of the wrapped value

Parameters:

map - an Observable map to be wrapped

keyType - the type of key that map is permitted to hold

valueType - the type of value that map is permitted to hold

Returns:

a dynamically typesafe view of the specified map

Since:

JavaFX 8.0

See Also:

synchronizedObservableMap

public static <K, V> ObservableMap<K,V> synchronizedObservableMap(ObservableMap<K,V> map)

Creates and returns a synchronized wrapper on top of provided observable map.

Type Parameters:

K - the type of the wrapped key

V - the type of the wrapped value

Parameters:

map - the map to be "wrapped" in a synchronized map.

Returns:

A synchronized version of the observable map

Since:

JavaFX 8.0

See Also:

emptyObservableMap

public static <K, V> ObservableMap<K,V> emptyObservableMap()

Creates an empty unmodifiable observable map.

Type Parameters:

K - the type of the wrapped key

V - the type of the wrapped value

Returns:

An empty unmodifiable observable map

Since:

JavaFX 8.0

See Also:

observableIntegerArray

public static ObservableIntegerArray observableIntegerArray()

Creates a new empty observable integer array.

Returns:: a newly created ObservableIntegerArray
Since:: JavaFX 8.0

observableIntegerArray

public static ObservableIntegerArray observableIntegerArray(int... values)

Creates a new observable integer array with values set to it.

Parameters:: values - the values that will be in the new observable integer array
Returns:: a newly created ObservableIntegerArray
Since:: JavaFX 8.0

observableIntegerArray

public static ObservableIntegerArray observableIntegerArray(ObservableIntegerArray array)

Creates a new observable integer array with copy of elements in given array.

Parameters:: array - observable integer array to copy
Returns:: a newly created ObservableIntegerArray
Since:: JavaFX 8.0

observableFloatArray

public static ObservableFloatArray observableFloatArray()

Creates a new empty observable float array.

Returns:: a newly created ObservableFloatArray
Since:: JavaFX 8.0

observableFloatArray

public static ObservableFloatArray observableFloatArray(float... values)

Creates a new observable float array with values set to it.

Parameters:: values - the values that will be in the new observable float array
Returns:: a newly created ObservableFloatArray
Since:: JavaFX 8.0

observableFloatArray

public static ObservableFloatArray observableFloatArray(ObservableFloatArray array)

Creates a new observable float array with copy of elements in given array.

Parameters:: array - observable float array to copy
Returns:: a newly created ObservableFloatArray
Since:: JavaFX 8.0

observableArrayList

public static <E> ObservableList<E> observableArrayList()

Creates a new empty observable list that is backed by an array list.

Type Parameters:

E - The type of List to be wrapped

Returns:

a newly created ObservableList

See Also:

observableArrayList

public static <E> ObservableList<E> observableArrayList(Callback<E,Observable[]> extractor)

Creates a new empty ObservableList that is backed by an array list and listens to changes in observables of its items.

The extractor returns observables (usually properties) of the objects in the created list. These observables are listened for changes and the user is notified of these through an update change of an attached ListChangeListener. These changes are unrelated to the changes made to the observable list itself using methods such as add and remove.

For example, a list of Shapes can listen to changes in the shapes' fill property.

Type Parameters:

E - The type of List to be wrapped

Parameters:

extractor - element to Observable[] converter

Returns:

a newly created ObservableList

Since:

JavaFX 2.1

See Also:

observableArrayList

public static <E> ObservableList<E> observableArrayList(E... items)

Creates a new observable array list with items added to it.

Type Parameters:

E - The type of List to be wrapped

Parameters:

items - the items that will be in the new observable ArrayList

Returns:

a newly created observableArrayList

See Also:

observableArrayList

public static <E> ObservableList<E> observableArrayList(Collection<? extends E> col)

Creates a new observable array list and adds a content of collection col to it.

Type Parameters:: E - The type of List to be wrapped
Parameters:: col - a collection which content should be added to the observableArrayList
Returns:: a newly created observableArrayList

observableHashMap

public static <K, V> ObservableMap<K,V> observableHashMap()

Creates a new empty observable map that is backed by a HashMap.

Type Parameters:: K - the type of the wrapped key; V - the type of the wrapped value
Returns:: a newly created observable HashMap

concat

public static <E> ObservableList<E> concat(ObservableList<E>... lists)

Concatenates more observable lists into one. The resulting list would be backed by an array list.

Type Parameters:: E - The type of List to be wrapped
Parameters:: lists - lists to concatenate
Returns:: new observable array list concatenated from the arguments

unmodifiableObservableList

public static <E> ObservableList<E> unmodifiableObservableList(ObservableList<E> list)

Creates and returns unmodifiable wrapper list on top of provided observable list.

Type Parameters:

E - The type of List to be wrapped

Parameters:

list - an ObservableList that is to be wrapped

Returns:

an ObserableList wrapper that is unmodifiable

See Also:

checkedObservableList

public static <E> ObservableList<E> checkedObservableList(ObservableList<E> list, Class<E> type)

Creates and returns a typesafe wrapper on top of provided observable list.

Type Parameters:

E - The type of List to be wrapped

Parameters:

list - an Observable list to be wrapped

type - the type of element that list is permitted to hold

Returns:

a dynamically typesafe view of the specified list

See Also:

synchronizedObservableList

public static <E> ObservableList<E> synchronizedObservableList(ObservableList<E> list)

Creates and returns a synchronized wrapper on top of provided observable list.

Type Parameters:

E - The type of List to be wrapped

Parameters:

list - the list to be "wrapped" in a synchronized list.

Returns:

A synchronized version of the observable list

See Also:

emptyObservableList

public static <E> ObservableList<E> emptyObservableList()

Creates an empty unmodifiable observable list.

Type Parameters:

E - The type of List to be wrapped

Returns:

An empty unmodifiable observable list

See Also:

singletonObservableList

public static <E> ObservableList<E> singletonObservableList(E e)

Creates an unmodifiable observable list with single element.

Type Parameters:

E - The type of List to be wrapped

Parameters:

e - the only elements that will be contained in this singleton observable list

Returns:

a singleton observable list

See Also:

unmodifiableObservableSet

public static <E> ObservableSet<E> unmodifiableObservableSet(ObservableSet<E> set)

Creates and returns unmodifiable wrapper on top of provided observable set.

Type Parameters:

E - The type of List to be wrapped

Parameters:

set - an ObservableSet that is to be wrapped

Returns:

an ObserableSet wrapper that is unmodifiable

Since:

JavaFX 8.0

See Also:

checkedObservableSet

public static <E> ObservableSet<E> checkedObservableSet(ObservableSet<E> set, Class<E> type)

Creates and returns a typesafe wrapper on top of provided observable set.

Type Parameters:

E - The type of List to be wrapped

Parameters:

set - an Observable set to be wrapped

type - the type of element that set is permitted to hold

Returns:

a dynamically typesafe view of the specified set

Since:

JavaFX 8.0

See Also:

synchronizedObservableSet

public static <E> ObservableSet<E> synchronizedObservableSet(ObservableSet<E> set)

Creates and returns a synchronized wrapper on top of provided observable set.

Type Parameters:

E - The type of List to be wrapped

Parameters:

set - the set to be "wrapped" in a synchronized set.

Returns:

A synchronized version of the observable set

Since:

JavaFX 8.0

See Also:

emptyObservableSet

public static <E> ObservableSet<E> emptyObservableSet()

Creates an empty unmodifiable observable set.

Type Parameters:

E - The type of List to be wrapped

Returns:

An empty unmodifiable observable set

Since:

JavaFX 8.0

See Also:

copy

public static <T> void copy(ObservableList<? super T> dest, List<? extends T> src)

Copies elements from src to dest. Fires only one change notification on dest.

Type Parameters:

T - The type of List to be wrapped

Parameters:

dest - the destination observable list

src - the source list

See Also:

fill

public static <T> void fill(ObservableList<? super T> list, T obj)

Fills the provided list with obj. Fires only one change notification on the list.

Type Parameters:

T - The type of List to be wrapped

Parameters:

list - the list to fill

obj - the object to fill the list with

See Also:

replaceAll

public static <T> boolean replaceAll(ObservableList<T> list, T oldVal, T newVal)

Replace all oldVal elements in the list with newVal element. Fires only one change notification on the list.

Type Parameters:

T - The type of List to be wrapped

Parameters:

list - the list which will have it's elements replaced

oldVal - the element that is going to be replace

newVal - the replacement

Returns:

true if the list was modified

See Also:

reverse

public static void reverse(ObservableList list)

Reverses the order in the list. Fires only one change notification on the list.

Parameters:

list - the list to be reversed

See Also:

rotate

public static void rotate(ObservableList list, int distance)

Rotates the list by distance. Fires only one change notification on the list.

Parameters:

list - the list to be rotated

distance - the distance of rotation

See Also:

shuffle

public static void shuffle(ObservableList<?> list)

Shuffles all elements in the observable list. Fires only one change notification on the list.

Parameters:

list - the list to shuffle

See Also:

shuffle

public static void shuffle(ObservableList list, Random rnd)

Shuffles all elements in the observable list. Fires only one change notification on the list.

Parameters:

list - the list to be shuffled

rnd - the random generator used for shuffling

See Also:

sort

public static <T extends Comparable<? super T>> void sort(ObservableList<T> list)

Sorts the provided observable list as specified in Collections.sort(List). Fires only one change notification on the list.

Type Parameters:: T - the type of elements in this list
Parameters:: list - the list to be sorted

sort

public static <T> void sort(ObservableList<T> list, Comparator<? super T> comparator)

Sorts the provided observable list as specified in Collections.sort(List, Comparator). Fires only one change notification on the list.

Type Parameters:: T - the type of elements in this list
Parameters:: list - the list to sort; comparator - the comparator to determine the order of the list. A null value indicates that the elements' natural ordering should be used.

© 2008, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from JavaFX API Documentation.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Java, JavaFX and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.