ConcurrentSkipListSet (Java Platform SE 6) (original) (raw)
java.util.concurrent
Class ConcurrentSkipListSet
java.lang.Object
java.util.AbstractCollection
java.util.AbstractSet
java.util.concurrent.ConcurrentSkipListSet
Type Parameters:
E - the type of elements maintained by this set
All Implemented Interfaces:
Serializable, Cloneable, Iterable, Collection, NavigableSet, Set, SortedSet
public class ConcurrentSkipListSet
extends AbstractSet
implements NavigableSet, Cloneable, Serializable
A scalable concurrent NavigableSet implementation based on a ConcurrentSkipListMap. The elements of the set are kept sorted according to their natural ordering, or by a Comparator provided at set creation time, depending on which constructor is used.
This implementation provides expected average log(n) time cost for the contains, add, and remove operations and their variants. Insertion, removal, and access operations safely execute concurrently by multiple threads. Iterators are weakly consistent, returning elements reflecting the state of the set at some point at or since the creation of the iterator. They do not throw ConcurrentModificationException, and may proceed concurrently with other operations. Ascending ordered views and their iterators are faster than descending ones.
Beware that, unlike in most collections, the size method is not a constant-time operation. Because of the asynchronous nature of these sets, determining the current number of elements requires a traversal of the elements. Additionally, the bulk operations addAll, removeAll,retainAll, and containsAll are not guaranteed to be performed atomically. For example, an iterator operating concurrently with an addAll operation might view only some of the added elements.
This class and its iterators implement all of the_optional_ methods of the Set and Iterator interfaces. Like most other concurrent collection implementations, this class does not permit the use of null elements, because null arguments and return values cannot be reliably distinguished from the absence of elements.
This class is a member of the Java Collections Framework.
Since:
1.6
See Also:
| Constructor Summary |
|---|
| ConcurrentSkipListSet() Constructs a new, empty set that orders its elements according to their natural ordering. |
| ConcurrentSkipListSet(Collection<? extends E> c) Constructs a new set containing the elements in the specified collection, that orders its elements according to theirnatural ordering. |
| ConcurrentSkipListSet(Comparator<? super E> comparator) Constructs a new, empty set that orders its elements according to the specified comparator. |
| ConcurrentSkipListSet(SortedSet<E> s) Constructs a new set containing the same elements and using the same ordering as the specified sorted set. |
| Method Summary | |
|---|---|
| boolean | add(E e) Adds the specified element to this set if it is not already present. |
| E | ceiling(E e) Returns the least element in this set greater than or equal to the given element, or null if there is no such element. |
| void | clear() Removes all of the elements from this set. |
| ConcurrentSkipListSet<E> | clone() Returns a shallow copy of this ConcurrentSkipListSet instance. |
| 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. |
| boolean | contains(Object o) Returns true if this set contains the specified element. |
| Iterator<E> | descendingIterator() Returns an iterator over the elements in this set in descending order. |
| NavigableSet<E> | descendingSet() Returns a reverse order view of the elements contained in this set. |
| boolean | equals(Object o) Compares the specified object with this set for equality. |
| E | first() Returns the first (lowest) element currently in this set. |
| E | floor(E e) Returns the greatest element in this set less than or equal to the given element, or null if there is no such element. |
| NavigableSet<E> | headSet(E toElement) Returns a view of the portion of this set whose elements are strictly less than toElement. |
| NavigableSet<E> | [headSet](../../../java/util/concurrent/ConcurrentSkipListSet.html#headSet%28E, boolean%29)(E toElement, boolean inclusive) Returns a view of the portion of this set whose elements are less than (or equal to, if inclusive is true) toElement. |
| E | higher(E e) Returns the least element in this set strictly greater than the given element, or null if there is no such element. |
| boolean | isEmpty() Returns true if this set contains no elements. |
| Iterator<E> | iterator() Returns an iterator over the elements in this set in ascending order. |
| E | last() Returns the last (highest) element currently in this set. |
| E | lower(E e) Returns the greatest element in this set strictly less than the given element, or null if there is no such element. |
| E | pollFirst() Retrieves and removes the first (lowest) element, or returns null if this set is empty. |
| E | pollLast() Retrieves and removes the last (highest) element, or returns null if this set is empty. |
| boolean | remove(Object o) Removes the specified element from this set if it is present. |
| boolean | removeAll(Collection<?> c) Removes from this set all of its elements that are contained in the specified collection. |
| int | size() Returns the number of elements in this set. |
| NavigableSet<E> | [subSet](../../../java/util/concurrent/ConcurrentSkipListSet.html#subSet%28E, boolean, E, boolean%29)(E fromElement, boolean fromInclusive,E toElement, boolean toInclusive) Returns a view of the portion of this set whose elements range fromfromElement to toElement. |
| NavigableSet<E> | [subSet](../../../java/util/concurrent/ConcurrentSkipListSet.html#subSet%28E, E%29)(E fromElement,E toElement) Returns a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive. |
| NavigableSet<E> | tailSet(E fromElement) Returns a view of the portion of this set whose elements are greater than or equal to fromElement. |
| NavigableSet<E> | [tailSet](../../../java/util/concurrent/ConcurrentSkipListSet.html#tailSet%28E, boolean%29)(E fromElement, boolean inclusive) Returns a view of the portion of this set whose elements are greater than (or equal to, if inclusive is true) fromElement. |
| Methods inherited from class java.util.AbstractSet |
|---|
| hashCode |
| Methods inherited from class java.util.AbstractCollection |
|---|
| addAll, containsAll, retainAll, toArray, toArray, toString |
| Methods inherited from class java.lang.Object |
|---|
| finalize, getClass, notify, notifyAll, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29) |
| Methods inherited from interface java.util.Set |
|---|
| addAll, containsAll, hashCode, retainAll, toArray, toArray |
| Constructor Detail |
|---|
ConcurrentSkipListSet
public ConcurrentSkipListSet()
Constructs a new, empty set that orders its elements according to their natural ordering.
ConcurrentSkipListSet
public ConcurrentSkipListSet(Comparator<? super E> comparator)
Constructs a new, empty set that orders its elements according to the specified comparator.
Parameters:
comparator - the comparator that will be used to order this set. If null, the natural ordering of the elements will be used.
ConcurrentSkipListSet
public ConcurrentSkipListSet(Collection<? extends E> c)
Constructs a new set containing the elements in the specified collection, that orders its elements according to theirnatural ordering.
Parameters:
c - The elements that will comprise the new set
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the elements in c are not Comparable, or are not mutually comparable
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified collection or any of its elements are null
ConcurrentSkipListSet
public ConcurrentSkipListSet(SortedSet<E> s)
Constructs a new set containing the same elements and using the same ordering as the specified sorted set.
Parameters:
s - sorted set whose elements will comprise the new set
Throws:
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified sorted set or any of its elements are null
| Method Detail |
|---|
clone
public ConcurrentSkipListSet<E> clone()
Returns a shallow copy of this ConcurrentSkipListSet instance. (The elements themselves are not cloned.)
Overrides:
[clone](../../../java/lang/Object.html#clone%28%29) in class [Object](../../../java/lang/Object.html "class in java.lang")
Returns:
a shallow copy of this set
See Also:
size
public int size()
Returns the number of elements in this set. If this set contains more than Integer.MAX_VALUE elements, it returns Integer.MAX_VALUE.
Beware that, unlike in most collections, this method is_NOT_ a constant-time operation. Because of the asynchronous nature of these sets, determining the current number of elements requires traversing them all to count them. Additionally, it is possible for the size to change during execution of this method, in which case the returned result will be inaccurate. Thus, this method is typically not very useful in concurrent applications.
Specified by:
[size](../../../java/util/Collection.html#size%28%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[size](../../../java/util/Set.html#size%28%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[size](../../../java/util/AbstractCollection.html#size%28%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
the number of elements in this set
isEmpty
public boolean isEmpty()
Returns true if this set contains no elements.
Specified by:
[isEmpty](../../../java/util/Collection.html#isEmpty%28%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[isEmpty](../../../java/util/Set.html#isEmpty%28%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[isEmpty](../../../java/util/AbstractCollection.html#isEmpty%28%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
true if this set contains no elements
contains
public boolean contains(Object o)
Returns true if this set contains the specified element. More formally, returns true if and only if this set contains an element e such that o.equals(e).
Specified by:
[contains](../../../java/util/Collection.html#contains%28java.lang.Object%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[contains](../../../java/util/Set.html#contains%28java.lang.Object%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[contains](../../../java/util/AbstractCollection.html#contains%28java.lang.Object%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
o - object to be checked for containment in this set
Returns:
true if this set contains the specified element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the specified element cannot be compared with the elements currently in this set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
add
public boolean add(E e)
Adds the specified element to this set if it is not already present. More formally, adds the specified element e to this set if the set contains no element e2 such that e.equals(e2). If this set already contains the element, the call leaves the set unchanged and returns false.
Specified by:
[add](../../../java/util/Collection.html#add%28E%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[add](../../../java/util/Set.html#add%28E%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[add](../../../java/util/AbstractCollection.html#add%28E%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
e - element to be added to this set
Returns:
true if this set did not already contain the specified element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if e cannot be compared with the elements currently in this set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
remove
public boolean remove(Object o)
Removes the specified element from this set if it is present. More formally, removes an element e such thato.equals(e), if this set contains such an element. Returns true if this set contained the element (or equivalently, if this set changed as a result of the call). (This set will not contain the element once the call returns.)
Specified by:
[remove](../../../java/util/Collection.html#remove%28java.lang.Object%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[remove](../../../java/util/Set.html#remove%28java.lang.Object%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[remove](../../../java/util/AbstractCollection.html#remove%28java.lang.Object%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
o - object to be removed from this set, if present
Returns:
true if this set contained the specified element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if o cannot be compared with the elements currently in this set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
clear
public void clear()
Removes all of the elements from this set.
Specified by:
[clear](../../../java/util/Collection.html#clear%28%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[clear](../../../java/util/Set.html#clear%28%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[clear](../../../java/util/AbstractCollection.html#clear%28%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
iterator
Returns an iterator over the elements in this set in ascending order.
Specified by:
[iterator](../../../java/lang/Iterable.html#iterator%28%29) in interface [Iterable](../../../java/lang/Iterable.html "interface in java.lang")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[iterator](../../../java/util/Collection.html#iterator%28%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[iterator](../../../java/util/NavigableSet.html#iterator%28%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[iterator](../../../java/util/Set.html#iterator%28%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[iterator](../../../java/util/AbstractCollection.html#iterator%28%29) in class [AbstractCollection](../../../java/util/AbstractCollection.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
an iterator over the elements in this set in ascending order
descendingIterator
public Iterator<E> descendingIterator()
Returns an iterator over the elements in this set in descending order.
Specified by:
[descendingIterator](../../../java/util/NavigableSet.html#descendingIterator%28%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
an iterator over the elements in this set in descending order
equals
public boolean equals(Object o)
Compares the specified object with this set for equality. Returnstrue if the specified object is also a set, the two sets have the same size, and every member of the specified set is contained in this set (or equivalently, every member of this set is contained in the specified set). This definition ensures that the equals method works properly across different implementations of the set interface.
Specified by:
[equals](../../../java/util/Collection.html#equals%28java.lang.Object%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[equals](../../../java/util/Set.html#equals%28java.lang.Object%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[equals](../../../java/util/AbstractSet.html#equals%28java.lang.Object%29) in class [AbstractSet](../../../java/util/AbstractSet.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
o - the object to be compared for equality with this set
Returns:
true if the specified object is equal to this set
See Also:
removeAll
public boolean removeAll(Collection<?> c)
Removes from this set all of its elements that are contained in the specified collection. If the specified collection is also a set, this operation effectively modifies this set so that its value is the asymmetric set difference of the two sets.
Specified by:
[removeAll](../../../java/util/Collection.html#removeAll%28java.util.Collection%29) in interface [Collection](../../../java/util/Collection.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[removeAll](../../../java/util/Set.html#removeAll%28java.util.Collection%29) in interface [Set](../../../java/util/Set.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Overrides:
[removeAll](../../../java/util/AbstractSet.html#removeAll%28java.util.Collection%29) in class [AbstractSet](../../../java/util/AbstractSet.html "class in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
c - collection containing elements to be removed from this set
Returns:
true if this set changed as a result of the call
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the types of one or more elements in this set are incompatible with the specified collection
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified collection or any of its elements are null
See Also:
AbstractCollection.remove(Object), AbstractCollection.contains(Object)
lower
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#lower%28E%29)
Returns the greatest element in this set strictly less than the given element, or null if there is no such element.
Specified by:
[lower](../../../java/util/NavigableSet.html#lower%28E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
e - the value to match
Returns:
the greatest element less than e, or null if there is no such element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the specified element cannot be compared with the elements currently in the set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
floor
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#floor%28E%29)
Returns the greatest element in this set less than or equal to the given element, or null if there is no such element.
Specified by:
[floor](../../../java/util/NavigableSet.html#floor%28E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
e - the value to match
Returns:
the greatest element less than or equal to e, or null if there is no such element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the specified element cannot be compared with the elements currently in the set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
ceiling
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#ceiling%28E%29)
Returns the least element in this set greater than or equal to the given element, or null if there is no such element.
Specified by:
[ceiling](../../../java/util/NavigableSet.html#ceiling%28E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
e - the value to match
Returns:
the least element greater than or equal to e, or null if there is no such element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the specified element cannot be compared with the elements currently in the set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
higher
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#higher%28E%29)
Returns the least element in this set strictly greater than the given element, or null if there is no such element.
Specified by:
[higher](../../../java/util/NavigableSet.html#higher%28E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
e - the value to match
Returns:
the least element greater than e, or null if there is no such element
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if the specified element cannot be compared with the elements currently in the set
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if the specified element is null
pollFirst
public E pollFirst()
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#pollFirst%28%29)
Retrieves and removes the first (lowest) element, or returns null if this set is empty.
Specified by:
[pollFirst](../../../java/util/NavigableSet.html#pollFirst%28%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
the first element, or null if this set is empty
pollLast
public E pollLast()
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#pollLast%28%29)
Retrieves and removes the last (highest) element, or returns null if this set is empty.
Specified by:
[pollLast](../../../java/util/NavigableSet.html#pollLast%28%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
the last element, or null if this set is empty
comparator
public Comparator<? super E> comparator()
Description copied from interface: [SortedSet](../../../java/util/SortedSet.html#comparator%28%29)
Returns the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements.
Specified by:
[comparator](../../../java/util/SortedSet.html#comparator%28%29) in interface [SortedSet](../../../java/util/SortedSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements
first
public E first()
Description copied from interface: [SortedSet](../../../java/util/SortedSet.html#first%28%29)
Returns the first (lowest) element currently in this set.
Specified by:
[first](../../../java/util/SortedSet.html#first%28%29) in interface [SortedSet](../../../java/util/SortedSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
the first (lowest) element currently in this set
Throws:
[NoSuchElementException](../../../java/util/NoSuchElementException.html "class in java.util") - if this set is empty
last
public E last()
Description copied from interface: [SortedSet](../../../java/util/SortedSet.html#last%28%29)
Returns the last (highest) element currently in this set.
Specified by:
[last](../../../java/util/SortedSet.html#last%28%29) in interface [SortedSet](../../../java/util/SortedSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
the last (highest) element currently in this set
Throws:
[NoSuchElementException](../../../java/util/NoSuchElementException.html "class in java.util") - if this set is empty
subSet
public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive)
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#subSet%28E, boolean, E, boolean%29)
Returns a view of the portion of this set whose elements range fromfromElement to toElement. If fromElement andtoElement are equal, the returned set is empty unless fromExclusive and toExclusive are both true. 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.
Specified by:
[subSet](../../../java/util/NavigableSet.html#subSet%28E, boolean, E, boolean%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
fromElement - low endpoint of the returned set
fromInclusive - true if the low endpoint is to be included in the returned view
toElement - high endpoint of the returned set
toInclusive - true if the high endpoint is to be included in the returned view
Returns:
a view of the portion of this set whose elements range fromfromElement, inclusive, to toElement, exclusive
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if fromElement andtoElement 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 ortoElement cannot be compared to elements currently in the set.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if fromElement ortoElement is null
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if fromElement is greater than toElement; or if this set itself has a restricted range, and fromElement ortoElement lies outside the bounds of the range.
headSet
public NavigableSet<E> headSet(E toElement, boolean inclusive)
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#headSet%28E, boolean%29)
Returns a view of the portion of this set whose elements are less than (or equal to, if inclusive is true) 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.
Specified by:
[headSet](../../../java/util/NavigableSet.html#headSet%28E, boolean%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
toElement - high endpoint of the returned set
inclusive - true if the high endpoint is to be included in the returned view
Returns:
a view of the portion of this set whose elements are less than (or equal to, if inclusive is true) toElement
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - 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](../../../java/lang/NullPointerException.html "class in java.lang") - if toElement is null
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if this set itself has a restricted range, and toElement lies outside the bounds of the range
tailSet
public NavigableSet<E> tailSet(E fromElement, boolean inclusive)
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#tailSet%28E, boolean%29)
Returns a view of the portion of this set whose elements are greater than (or equal to, if inclusive is true) 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.
Specified by:
[tailSet](../../../java/util/NavigableSet.html#tailSet%28E, boolean%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
fromElement - low endpoint of the returned set
inclusive - true if the low endpoint is to be included in the returned view
Returns:
a view of the portion of this set whose elements are greater than or equal to fromElement
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - 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](../../../java/lang/NullPointerException.html "class in java.lang") - if fromElement is null
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if this set itself has a restricted range, and fromElement lies outside the bounds of the range
subSet
public NavigableSet<E> subSet(E fromElement, E toElement)
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#subSet%28E, E%29)
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.
Equivalent to subSet(fromElement, true, toElement, false).
Specified by:
[subSet](../../../java/util/NavigableSet.html#subSet%28E, E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[subSet](../../../java/util/SortedSet.html#subSet%28E, E%29) in interface [SortedSet](../../../java/util/SortedSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
fromElement - low endpoint (inclusive) of the returned set
toElement - high endpoint (exclusive) of the returned set
Returns:
a view of the portion of this set whose elements range fromfromElement, inclusive, to toElement, exclusive
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - if fromElement andtoElement 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 ortoElement cannot be compared to elements currently in the set.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang") - if fromElement ortoElement is null
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if fromElement is greater than toElement; or if this set itself has a restricted range, and fromElement ortoElement lies outside the bounds of the range
headSet
public NavigableSet<E> headSet(E toElement)
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#headSet%28E%29)
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.
Equivalent to headSet(toElement, false).
Specified by:
[headSet](../../../java/util/NavigableSet.html#headSet%28E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[headSet](../../../java/util/SortedSet.html#headSet%28E%29) in interface [SortedSet](../../../java/util/SortedSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
toElement - high endpoint (exclusive) of the returned set
Returns:
a view of the portion of this set whose elements are strictly less than toElement
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - 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](../../../java/lang/NullPointerException.html "class in java.lang") - if toElement is null
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if this set itself has a restricted range, and toElement lies outside the bounds of the range na
tailSet
public NavigableSet<E> tailSet(E fromElement)
Description copied from interface: [NavigableSet](../../../java/util/NavigableSet.html#tailSet%28E%29)
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.
Equivalent to tailSet(fromElement, true).
Specified by:
[tailSet](../../../java/util/NavigableSet.html#tailSet%28E%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Specified by:
[tailSet](../../../java/util/SortedSet.html#tailSet%28E%29) in interface [SortedSet](../../../java/util/SortedSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Parameters:
fromElement - low endpoint (inclusive) of the returned set
Returns:
a view of the portion of this set whose elements are greater than or equal to fromElement
Throws:
[ClassCastException](../../../java/lang/ClassCastException.html "class in java.lang") - 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](../../../java/lang/NullPointerException.html "class in java.lang") - if fromElement is null
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if this set itself has a restricted range, and fromElement lies outside the bounds of the range
descendingSet
public NavigableSet<E> descendingSet()
Returns a reverse order view of the elements contained in this set. The descending set is backed by this set, so changes to the set are reflected in the descending set, and vice-versa.
The returned set has an ordering equivalent toCollections.reverseOrder(comparator()). The expression s.descendingSet().descendingSet() returns a view of s essentially equivalent to s.
Specified by:
[descendingSet](../../../java/util/NavigableSet.html#descendingSet%28%29) in interface [NavigableSet](../../../java/util/NavigableSet.html "interface in java.util")<[E](../../../java/util/concurrent/ConcurrentSkipListSet.html "type parameter in ConcurrentSkipListSet")>
Returns:
a reverse order view of this set
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