OpenJDK 1.22 · java.util.SortedSet · APIdia, the JavaDoc alternative

A Set that further provides a total ordering on its elements. The elements are ordered using their natural ordering, or by a Comparator typically provided at sorted set creation time. The set's iterator will traverse the set in ascending element order. Several additional operations are provided to take advantage of the ordering. (This interface is the set analogue of SortedMap.)

All elements inserted into a sorted set must implement the Comparable interface (or be accepted by the specified comparator). Furthermore, all such elements must be mutually comparable: e1.compareTo(e2) (or comparator.compare(e1, e2)) must not throw a ClassCastException for any elements e1 and e2 in the sorted set. Attempts to violate this restriction will cause the offending method or constructor invocation to throw a ClassCastException.

Note that the ordering maintained by a sorted set (whether or not an explicit comparator is provided) must be consistent with equals if the sorted set is to correctly implement the Set interface. (See the Comparable interface or Comparator interface for a precise definition of consistent with equals.) This is so because the Set interface is defined in terms of the equals operation, but a sorted set performs all element comparisons using its compareTo (or compare) method, so two elements that are deemed equal by this method are, from the standpoint of the sorted set, equal. The behavior of a sorted set is well-defined even if its ordering is inconsistent with equals; it just fails to obey the general contract of the Set interface.

All general-purpose sorted set implementation classes should provide four "standard" constructors: 1) A void (no arguments) constructor, which creates an empty sorted set sorted according to the natural ordering of its elements. 2) A constructor with a single argument of type Comparator, which creates an empty sorted set sorted according to the specified comparator. 3) A constructor with a single argument of type Collection, which creates a new sorted set with the same elements as its argument, sorted according to the natural ordering of the elements. 4) A constructor with a single argument of type SortedSet, which creates a new sorted set with the same elements and the same ordering as the input sorted set. There is no way to enforce this recommendation, as interfaces cannot contain constructors.

Note

several methods return subsets with restricted ranges. Such ranges are half-open, that is, they include their low endpoint but not their high endpoint (where applicable). If you need a closed range (which includes both endpoints), and the element type allows for calculation of the successor of a given value, merely request the subrange from lowEndpoint to successor(highEndpoint). For example, suppose that s is a sorted set of strings. The following idiom obtains a view containing all of the strings in s from low to high, inclusive:

  SortedSet<String> sub = s.subSet(low, high+"\0");

A similar technique can be used to generate an open range (which contains neither endpoint). The following idiom obtains a view containing all of the Strings in s from low to high, exclusive:

  SortedSet<String> sub = s.subSet(low+"\0", high);

This interface is a member of the Java Collections Framework.

Method Summary

Modifier and Type	Method and Description
public default void	addFirst(E the element to be added e) Overrides default java.util.SequencedCollection.addFirst. Throws `UnsupportedOperationException`.
public default void	addLast(E the element to be added. e) Overrides default java.util.SequencedCollection.addLast. Throws `UnsupportedOperationException`.
public Comparator<? super E>	Returns: the comparator used to order the elements in this set, or `null` if this set uses the natural ordering of its elements comparator() Returns the comparator used to order the elements in this set, or `null` if this set uses the natural ordering of its elements.
public E	Returns: the first (lowest) element currently in this set first() Returns the first (lowest) element currently in this set.
public default E	getFirst() Overrides default java.util.SequencedCollection.getFirst. Gets the first element of this collection.
public default E	getLast() Overrides default java.util.SequencedCollection.getLast. Gets the last element of this collection.
public SortedSet<E>	Returns: a view of the portion of this set whose elements are strictly less than `toElement` headSet(E high endpoint (exclusive) of the returned set toElement) Returns a view of the portion of this set whose elements are strictly less than `toElement`.
public E	Returns: the last (highest) element currently in this set last() Returns the last (highest) element currently in this set.
public default E	removeFirst() Overrides default java.util.SequencedCollection.removeFirst. Removes and returns the first element of this collection (optional operation).
public default E	removeLast() Overrides default java.util.SequencedCollection.removeLast. Removes and returns the last element of this collection (optional operation).
public default SortedSet<E>	Returns: a reverse-ordered view of this collection, as a `SortedSet` reversed() Implements java.util.SequencedSet.reversed. Returns a reverse-ordered view of this collection.
public default Spliterator<E>	Returns: a `Spliterator` over the elements in this sorted set spliterator() Overrides default java.util.Set.spliterator, java.util.Collection.spliterator. Creates a `Spliterator` over the elements in this sorted set.
public SortedSet<E>	Returns: a view of the portion of this set whose elements range from `fromElement`, inclusive, to `toElement`, exclusive subSet(E low endpoint (inclusive) of the returned set fromElement, E high endpoint (exclusive) of the returned set toElement) Returns a view of the portion of this set whose elements range from `fromElement`, inclusive, to `toElement`, exclusive.
public SortedSet<E>	Returns: a view of the portion of this set whose elements are greater than or equal to `fromElement` tailSet(E low endpoint (inclusive) of the returned set fromElement) Returns a view of the portion of this set whose elements are greater than or equal to `fromElement`.

Inherited from java.util.Set:: add addAll clear contains containsAll copyOf equals hashCode isEmpty iterator of of of of of of of of of of of of remove removeAll retainAll size toArray toArray

Method Detail

addFirst back to summary

addFirst	back to summary
public default void addFirst(E e) Overrides default java.util.SequencedCollection.addFirst. Throws `UnsupportedOperationException`. The encounter order induced by this set's comparison method determines the position of elements, so explicit positioning is not supported. Implementation Specification The implementation in this interface always throws `UnsupportedOperationException`. Parameters e:E Doc from java.util.SequencedCollection.addFirst. the element to be added Exceptions UnsupportedOperationException: always Since 21

public default void addFirst(E e)

Overrides default java.util.SequencedCollection.addFirst.

Throws UnsupportedOperationException. The encounter order induced by this set's comparison method determines the position of elements, so explicit positioning is not supported.

Implementation Specification

The implementation in this interface always throws UnsupportedOperationException.

Parameters

e:E

Doc from java.util.SequencedCollection.addFirst.

the element to be added

Exceptions

UnsupportedOperationException:: always

Since

addLast back to summary

addLast	back to summary
public default void addLast(E e) Overrides default java.util.SequencedCollection.addLast. Throws `UnsupportedOperationException`. The encounter order induced by this set's comparison method determines the position of elements, so explicit positioning is not supported. Implementation Specification The implementation in this interface always throws `UnsupportedOperationException`. Parameters e:E Doc from java.util.SequencedCollection.addLast. the element to be added. Exceptions UnsupportedOperationException: always Since 21

public default void addLast(E e)

Overrides default java.util.SequencedCollection.addLast.

Throws UnsupportedOperationException. The encounter order induced by this set's comparison method determines the position of elements, so explicit positioning is not supported.

Implementation Specification

The implementation in this interface always throws UnsupportedOperationException.

Parameters

e:E

Doc from java.util.SequencedCollection.addLast.

the element to be added.

Exceptions

UnsupportedOperationException:: always

Since

comparator back to summary

comparator	back to summary
public Comparator<? super E> comparator() Returns the comparator used to order the elements in this set, or `null` if this set uses the natural ordering of its elements. Returns:Comparator<? super E> the comparator used to order the elements in this set, or `null` if this set uses the natural ordering of its elements

public Comparator<? super E> comparator()

Returns the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements.

Returns:Comparator<? super E>: the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements

first	back to summary
public E first() Returns the first (lowest) element currently in this set. Returns:E the first (lowest) element currently in this set Exceptions NoSuchElementException: if this set is empty

first

back to summary

public E first()

Returns the first (lowest) element currently in this set.

Returns:E

the first (lowest) element currently in this set

Exceptions

NoSuchElementException:: if this set is empty

getFirst back to summary

getFirst	back to summary
public default E getFirst() Overrides default java.util.SequencedCollection.getFirst. Doc from java.util.SequencedCollection.getFirst. Gets the first element of this collection. Implementation Specification The implementation in this interface returns the result of calling the `first` method. Returns:E the retrieved element Exceptions NoSuchElementException: if this collection is empty Since 21

public default E getFirst()

Overrides default java.util.SequencedCollection.getFirst.

Doc from java.util.SequencedCollection.getFirst.

Gets the first element of this collection.

Implementation Specification

The implementation in this interface returns the result of calling the first method.

Returns:E

the retrieved element

Exceptions

NoSuchElementException:: if this collection is empty

Since

getLast back to summary

getLast	back to summary
public default E getLast() Overrides default java.util.SequencedCollection.getLast. Doc from java.util.SequencedCollection.getLast. Gets the last element of this collection. Implementation Specification The implementation in this interface returns the result of calling the `last` method. Returns:E the retrieved element Exceptions NoSuchElementException: if this collection is empty Since 21

public default E getLast()

Overrides default java.util.SequencedCollection.getLast.

Doc from java.util.SequencedCollection.getLast.

Gets the last element of this collection.

Implementation Specification

The implementation in this interface returns the result of calling the last method.

Returns:E

the retrieved element

Exceptions

NoSuchElementException:: if this collection is empty

Since

headSet back to summary

headSet	back to summary
public SortedSet<E> headSet(E toElement) Returns a view of the portion of this set whose elements are strictly less than `toElement`. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports. The returned set will throw an `IllegalArgumentException` on an attempt to insert an element outside its range. Parameters toElement:E high endpoint (exclusive) of the returned set Returns:SortedSet<E> a view of the portion of this set whose elements are strictly less than `toElement` Exceptions ClassCastException: if `toElement` is not compatible with this set's comparator (or, if the set has no comparator, if `toElement` does not implement `Comparable`). Implementations may, but are not required to, throw this exception if `toElement` cannot be compared to elements currently in the set. NullPointerException: if `toElement` is null and this set does not permit null elements IllegalArgumentException: if this set itself has a restricted range, and `toElement` lies outside the bounds of the range

public SortedSet<E> headSet(E toElement)

Returns a view of the portion of this set whose elements are strictly less than toElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Parameters

toElement:E: high endpoint (exclusive) of the returned set

Returns:SortedSet<E>

a view of the portion of this set whose elements are strictly less than toElement

Exceptions

ClassCastException:: if toElement is not compatible with this set's comparator (or, if the set has no comparator, if toElement does not implement Comparable). Implementations may, but are not required to, throw this exception if toElement cannot be compared to elements currently in the set.
NullPointerException:: if toElement is null and this set does not permit null elements
IllegalArgumentException:: if this set itself has a restricted range, and toElement lies outside the bounds of the range

last	back to summary
public E last() Returns the last (highest) element currently in this set. Returns:E the last (highest) element currently in this set Exceptions NoSuchElementException: if this set is empty

last

back to summary

public E last()

Returns the last (highest) element currently in this set.

Returns:E

the last (highest) element currently in this set

Exceptions

NoSuchElementException:: if this set is empty

removeFirst back to summary

removeFirst	back to summary
public default E removeFirst() Overrides default java.util.SequencedCollection.removeFirst. Doc from java.util.SequencedCollection.removeFirst. Removes and returns the first element of this collection (optional operation). Implementation Specification The implementation in this interface calls the `first` method to obtain the first element, then it calls `remove(element)` to remove the element, and then it returns the element. Returns:E the removed element Exceptions NoSuchElementException: if this collection is empty UnsupportedOperationException: if this collection implementation does not support this operation Since 21

public default E removeFirst()

Overrides default java.util.SequencedCollection.removeFirst.

Doc from java.util.SequencedCollection.removeFirst.

Removes and returns the first element of this collection (optional operation).

Implementation Specification

The implementation in this interface calls the first method to obtain the first element, then it calls remove(element) to remove the element, and then it returns the element.

Returns:E

the removed element

Exceptions

NoSuchElementException:: if this collection is empty
UnsupportedOperationException:: if this collection implementation does not support this operation

Since

removeLast back to summary

removeLast	back to summary
public default E removeLast() Overrides default java.util.SequencedCollection.removeLast. Doc from java.util.SequencedCollection.removeLast. Removes and returns the last element of this collection (optional operation). Implementation Specification The implementation in this interface calls the `last` method to obtain the last element, then it calls `remove(element)` to remove the element, and then it returns the element. Returns:E the removed element Exceptions NoSuchElementException: if this collection is empty UnsupportedOperationException: if this collection implementation does not support this operation Since 21

public default E removeLast()

Overrides default java.util.SequencedCollection.removeLast.

Doc from java.util.SequencedCollection.removeLast.

Removes and returns the last element of this collection (optional operation).

Implementation Specification

The implementation in this interface calls the last method to obtain the last element, then it calls remove(element) to remove the element, and then it returns the element.

Returns:E

the removed element

Exceptions

NoSuchElementException:: if this collection is empty
UnsupportedOperationException:: if this collection implementation does not support this operation

Since

reversed back to summary

reversed	back to summary
public default SortedSet<E> reversed() Implements java.util.SequencedSet.reversed. Doc from java.util.SequencedSet.reversed. Returns a reverse-ordered view of this collection. The encounter order of elements in the returned view is the inverse of the encounter order of elements in this collection. The reverse ordering affects all order-sensitive operations, including those on the view collections of the returned view. If the collection implementation permits modifications to this view, the modifications "write through" to the underlying collection. Changes to the underlying collection might or might not be visible in this reversed view, depending upon the implementation. Implementation Specification The implementation in this interface returns a reverse-ordered SortedSet view. The `reversed()` method of the view returns a reference to this SortedSet. Other operations on the view are implemented via calls to public methods on this SortedSet. The exact relationship between calls on the view and calls on this SortedSet is unspecified. However, order-sensitive operations generally behave as if they delegate to the appropriate method with the opposite orientation. For example, calling `getFirst` on the view might result in a call to `getLast` on this SortedSet. Returns:SortedSet<E> a reverse-ordered view of this collection, as a `SortedSet` Since 21

public default SortedSet<E> reversed()

Implements java.util.SequencedSet.reversed.

Doc from java.util.SequencedSet.reversed.

Returns a reverse-ordered view of this collection. The encounter order of elements in the returned view is the inverse of the encounter order of elements in this collection. The reverse ordering affects all order-sensitive operations, including those on the view collections of the returned view. If the collection implementation permits modifications to this view, the modifications "write through" to the underlying collection. Changes to the underlying collection might or might not be visible in this reversed view, depending upon the implementation.

Implementation Specification

The implementation in this interface returns a reverse-ordered SortedSet view. The reversed() method of the view returns a reference to this SortedSet. Other operations on the view are implemented via calls to public methods on this SortedSet. The exact relationship between calls on the view and calls on this SortedSet is unspecified. However, order-sensitive operations generally behave as if they delegate to the appropriate method with the opposite orientation. For example, calling getFirst on the view might result in a call to getLast on this SortedSet.

Returns:SortedSet<E>: a reverse-ordered view of this collection, as a SortedSet
Since: 21

spliterator back to summary

spliterator	back to summary
public default Spliterator<E> spliterator() Overrides default java.util.Set.spliterator, java.util.Collection.spliterator. Creates a `Spliterator` over the elements in this sorted set. The `Spliterator` reports `Spliterator#DISTINCT`, `Spliterator#SORTED` and `Spliterator#ORDERED`. Implementations should document the reporting of additional characteristic values. The spliterator's comparator (see `java.util.Spliterator#getComparator()`) must be `null` if the sorted set's comparator (see `comparator()`) is `null`. Otherwise, the spliterator's comparator must be the same as or impose the same total ordering as the sorted set's comparator. Implementation Specification The default implementation creates a late-binding spliterator from the sorted set's `Iterator`. The spliterator inherits the fail-fast properties of the set's iterator. The spliterator's comparator is the same as the sorted set's comparator. The created `Spliterator` additionally reports `Spliterator#SIZED`. Implementation Note The created `Spliterator` additionally reports `Spliterator#SUBSIZED`. Returns:Spliterator<E> a `Spliterator` over the elements in this sorted set Annotations @Override Since 1.8

public default Spliterator<E> spliterator()

Overrides default java.util.Set.spliterator, java.util.Collection.spliterator.

Creates a Spliterator over the elements in this sorted set.

The Spliterator reports Spliterator#DISTINCT, Spliterator#SORTED and Spliterator#ORDERED. Implementations should document the reporting of additional characteristic values.

The spliterator's comparator (see java.util.Spliterator#getComparator()) must be null if the sorted set's comparator (see comparator()) is null. Otherwise, the spliterator's comparator must be the same as or impose the same total ordering as the sorted set's comparator.

Implementation Specification

The default implementation creates a late-binding spliterator from the sorted set's Iterator. The spliterator inherits the fail-fast properties of the set's iterator. The spliterator's comparator is the same as the sorted set's comparator.

The created Spliterator additionally reports Spliterator#SIZED.

Implementation Note

The created Spliterator additionally reports Spliterator#SUBSIZED.

Returns:Spliterator<E>

a Spliterator over the elements in this sorted set

Annotations

@Override

Since

1.8

subSet back to summary

subSet	back to summary
public SortedSet<E> subSet(E fromElement, E toElement) Returns a view of the portion of this set whose elements range from `fromElement`, inclusive, to `toElement`, exclusive. (If `fromElement` and `toElement` are equal, the returned set is empty.) The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports. The returned set will throw an `IllegalArgumentException` on an attempt to insert an element outside its range. Parameters fromElement:E low endpoint (inclusive) of the returned set toElement:E high endpoint (exclusive) of the returned set Returns:SortedSet<E> a view of the portion of this set whose elements range from `fromElement`, inclusive, to `toElement`, exclusive Exceptions ClassCastException: if `fromElement` and `toElement` cannot be compared to one another using this set's comparator (or, if the set has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if `fromElement` or `toElement` cannot be compared to elements currently in the set. NullPointerException: if `fromElement` or `toElement` is null and this set does not permit null elements IllegalArgumentException: if `fromElement` is greater than `toElement`; or if this set itself has a restricted range, and `fromElement` or `toElement` lies outside the bounds of the range

public SortedSet<E> subSet(E fromElement, E toElement)

Returns a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive. (If fromElement and toElement are equal, the returned set is empty.) The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Parameters

fromElement:E: low endpoint (inclusive) of the returned set
toElement:E: high endpoint (exclusive) of the returned set

Returns:SortedSet<E>

a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive

Exceptions

ClassCastException:: if fromElement and toElement cannot be compared to one another using this set's comparator (or, if the set has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if fromElement or toElement cannot be compared to elements currently in the set.
NullPointerException:: if fromElement or toElement is null and this set does not permit null elements
IllegalArgumentException:: if fromElement is greater than toElement; or if this set itself has a restricted range, and fromElement or toElement lies outside the bounds of the range

tailSet back to summary

tailSet	back to summary
public SortedSet<E> tailSet(E fromElement) Returns a view of the portion of this set whose elements are greater than or equal to `fromElement`. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports. The returned set will throw an `IllegalArgumentException` on an attempt to insert an element outside its range. Parameters fromElement:E low endpoint (inclusive) of the returned set Returns:SortedSet<E> a view of the portion of this set whose elements are greater than or equal to `fromElement` Exceptions ClassCastException: if `fromElement` is not compatible with this set's comparator (or, if the set has no comparator, if `fromElement` does not implement `Comparable`). Implementations may, but are not required to, throw this exception if `fromElement` cannot be compared to elements currently in the set. NullPointerException: if `fromElement` is null and this set does not permit null elements IllegalArgumentException: if this set itself has a restricted range, and `fromElement` lies outside the bounds of the range

public SortedSet<E> tailSet(E fromElement)

Returns a view of the portion of this set whose elements are greater than or equal to fromElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Parameters

fromElement:E: low endpoint (inclusive) of the returned set

Returns:SortedSet<E>

a view of the portion of this set whose elements are greater than or equal to fromElement

Exceptions

ClassCastException:: if fromElement is not compatible with this set's comparator (or, if the set has no comparator, if fromElement does not implement Comparable). Implementations may, but are not required to, throw this exception if fromElement cannot be compared to elements currently in the set.
NullPointerException:: if fromElement is null and this set does not permit null elements
IllegalArgumentException:: if this set itself has a restricted range, and fromElement lies outside the bounds of the range

public Interface SortedSet<E>

Method Summary

Method Detail