E
- the type of elements in this collectionCollection<E>
, Iterable<E>
BlockingDeque<E>
, Deque<E>
, List<E>
, NavigableSet<E>
, SequencedSet<E>
, SortedSet<E>
AbstractList
, AbstractSequentialList
, ArrayDeque
, ArrayList
, AttributeList
, ConcurrentLinkedDeque
, ConcurrentSkipListSet
, CopyOnWriteArrayList
, LinkedBlockingDeque
, LinkedHashSet
, LinkedList
, RoleList
, RoleUnresolvedList
, Stack
, TreeSet
, Vector
public interface SequencedCollection<E> extends Collection<E>
(Note that this definition does not imply anything about physical positioning of elements, such as their locations in a computer's memory.)
Several methods inherited from the Collection
interface are required to operate on elements according to this collection's encounter order. For instance, the iterator
method provides elements starting from the first element, proceeding through successive elements, until the last element. Other methods that are required to operate on elements in encounter order include the following: forEach
, parallelStream
, spliterator
, stream
, and all overloads of the toArray
method.
This interface provides methods to add, retrieve, and remove elements at either end of the collection.
This interface also defines the reversed
method, which provides a reverse-ordered view of this collection. In the reverse-ordered view, the concepts of first and last are inverted, as are the concepts of successor and predecessor. The first element of this collection is the last element of the reverse-ordered view, and vice-versa. The successor of some element in this collection is its predecessor in the reversed view, and vice-versa. All methods that respect the encounter order of the collection operate as if the encounter order is inverted. For instance, the Collection.iterator()
method of the reversed view reports the elements in order from the last element of this collection to the first. The availability of the reversed
method, and its impact on the ordering semantics of all applicable methods, allow convenient iteration, searching, copying, and streaming of the elements of this collection in either forward order or reverse order.
This class is a member of the Java Collections Framework.
equals
and hashCode
methods, because requirements imposed by sub-interfaces List
and SequencedSet
(which inherits requirements from Set
) would be in conflict. See the specifications for Collection.equals
and Collection.hashCode
for further information.Modifier and Type | Method | Description |
---|---|---|
default void |
addFirst |
Adds an element as the first element of this collection (optional operation). |
default void |
addLast |
Adds an element as the last element of this collection (optional operation). |
default E |
getFirst() |
Gets the first element of this collection. |
default E |
getLast() |
Gets the last element of this collection. |
default E |
removeFirst() |
Removes and returns the first element of this collection (optional operation). |
default E |
removeLast() |
Removes and returns the last element of this collection (optional operation). |
SequencedCollection |
reversed() |
Returns a reverse-ordered view of this collection. |
SequencedCollection<E> reversed()
default void addFirst(E e)
UnsupportedOperationException
.e
- the element to be addedNullPointerException
- if the specified element is null and this collection does not permit null elementsUnsupportedOperationException
- if this collection implementation does not support this operationdefault void addLast(E e)
UnsupportedOperationException
.e
- the element to be added.NullPointerException
- if the specified element is null and this collection does not permit null elementsUnsupportedOperationException
- if this collection implementation does not support this operationdefault E getFirst()
next
method. Any NoSuchElementException
thrown is propagated. Otherwise, it returns the element.NoSuchElementException
- if this collection is emptydefault E getLast()
next
method. Any NoSuchElementException
thrown is propagated. Otherwise, it returns the element.NoSuchElementException
- if this collection is emptydefault E removeFirst()
next
method. Any NoSuchElementException
thrown is propagated. It then calls the iterator's remove
method. Any UnsupportedOperationException
thrown is propagated. Then, it returns the element.NoSuchElementException
- if this collection is emptyUnsupportedOperationException
- if this collection implementation does not support this operationdefault E removeLast()
next
method. Any NoSuchElementException
thrown is propagated. It then calls the iterator's remove
method. Any UnsupportedOperationException
thrown is propagated. Then, it returns the element.NoSuchElementException
- if this collection is emptyUnsupportedOperationException
- if this collection implementation does not support this operation
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/SequencedCollection.html