Details
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.
| E | the type of elements maintained by this set |
| since | 1.6 |
| Methods |
|---|
| public boolean |
add(Object e) Details
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.
| e | element to be added to this set |
| return | true if this set did not already contain the
specified element |
| Throws | ClassCastException: if e cannot be compared
with the elements currently in this set |
| Throws | NullPointerException: als het gespecifieerde element null is |
|
| public Object |
ceiling(Object e) Details
|
| public void |
clear()
Removes all of the elements from this set.
|
| public ConcurrentSkipListSet |
clone() Details
Returns a shallow copy of this ConcurrentSkipListSet
instance. (The elements themselves are not cloned.)
| return | a shallow copy of this set |
|
| public Comparator |
comparator()
|
| public boolean |
contains(Object o) Details
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).
| o | object to be checked for containment in this set |
| return | true if this set contains the specified element |
| Throws | ClassCastException: if the specified element cannot be
compared with the elements currently in this set |
| Throws | NullPointerException: als het gespecifieerde element null is |
|
| public Iterator |
descendingIterator() Details
Returns an iterator over the elements in this set in descending order.
| return | an iterator over the elements in this set in descending order |
|
| public NavigableSet |
descendingSet() Details
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 to
Collections.reverseOrder(comparator()).
The expression s.descendingSet().descendingSet() returns a
view of s essentially equivalent to s.
| return | a reverse order view of this set |
|
| public boolean |
equals(Object o) Details
Compares the specified object with this set for equality. Returns
true 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.
| o | the object to be compared for equality with this set |
| return | true if the specified object is equal to this set |
|
| public Object |
first() Details
|
| public Object |
floor(Object e) Details
|
| public NavigableSet |
headSet(Object toElement, boolean inclusive) Details
| Throws | 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. |
| Throws | NullPointerException: if toElement is null |
| Throws | IllegalArgumentException: if this set itself has a
restricted range, and toElement lies outside the
bounds of the range |
|
| public NavigableSet |
headSet(Object toElement) Details
| Throws | 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. |
| Throws | NullPointerException: if toElement is null |
| Throws | IllegalArgumentException: if this set itself has a
restricted range, and toElement lies outside the
bounds of the range
na |
|
| public Object |
higher(Object e) Details
|
| public Iterator |
iterator() Details
Returns an iterator over the elements in this set in ascending order.
| return | an iterator over the elements in this set in ascending order |
|
| public Object |
last() Details
|
| public Object |
lower(Object e) Details
|
| public Object |
pollFirst()
|
| public Object |
pollLast()
|
| public boolean |
remove(Object o) Details
Removes the specified element from this set if it is present.
More formally, removes an element e such that
o.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.)
| o | object to be removed from this set, if present |
| return | true if this set contained the specified element |
| Throws | ClassCastException: if o cannot be compared
with the elements currently in this set |
| Throws | NullPointerException: als het gespecifieerde element null is |
|
| public boolean |
removeAll(Collection c) Details
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.
| c | collection containing elements to be removed from this set |
| return | true if this set changed as a result of the call |
| Throws | ClassCastException: if the types of one or more elements in this
set are incompatible with the specified collection |
| Throws | NullPointerException: if the specified collection or any
of its elements are null |
|
| public int |
size() Details
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.
| return | the number of elements in this set |
|
| public NavigableSet |
subSet(Object fromElement, boolean fromInclusive, Object toElement, boolean toInclusive) Details
| Throws | 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. |
| Throws | NullPointerException: if fromElement or
toElement is null |
| Throws | 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 NavigableSet |
subSet(Object fromElement, Object toElement) Details
| Throws | 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. |
| Throws | NullPointerException: if fromElement or
toElement is null |
| Throws | 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 NavigableSet |
tailSet(Object fromElement, boolean inclusive) Details
| Throws | 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. |
| Throws | NullPointerException: if fromElement is null |
| Throws | IllegalArgumentException: if this set itself has a
restricted range, and fromElement lies outside the
bounds of the range |
|
| public NavigableSet |
tailSet(Object fromElement) Details
| Throws | 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. |
| Throws | NullPointerException: if fromElement is null |
| Throws | IllegalArgumentException: if this set itself has a
restricted range, and fromElement lies outside the
bounds of the range |
|
