/* * Written by Doug Lea with assistance from members of JCP JSR-166 * Expert Group and released to the public domain, as explained at * http://creativecommons.org/licenses/publicdomain */ package java.util; import java.util.*; // for javadoc (till 6280605 is fixed) /** * A {@link SortedSet} extended with navigation methods reporting * closest matches for given search targets. Methods lower, * floor, ceiling, and higher return elements * respectively less than, less than or equal, greater than or equal, * and greater than a given element, returning null if there is * no such element. A NavigableSet may be viewed and traversed * in either ascending or descending order. The Collection * iterator method returns an ascending Iterator and * the additional method descendingIterator returns a * descending iterator. The performance of ascending traversals is * likely to be faster than descending traversals. This interface * additionally defines methods pollFirst and * pollLast that return and remove the lowest and highest * element, if one exists, else returning null. * Methods navigableSubSet, navigableHeadSet, and * navigableTailSet differ from the similarly named * SortedSet methods only in their declared return types. * Subsets of any NavigableSet must implement the * NavigableSet interface. * *
The return values of navigation methods may be ambiguous in * implementations that permit null elements. However, even * in this case the result can be disambiguated by checking * contains(null). To avoid such issues, implementations of * this interface are encouraged to not permit insertion of * null elements. (Note that sorted sets of {@link * Comparable} elements intrinsically do not permit null.) * *
This interface is a member of the
*
* Java Collections Framework.
*
* @author Doug Lea
* @param The returned set will throw an IllegalArgumentException
* on an attempt to insert an element outside its range.
*
* @param fromElement low endpoint (inclusive) of the returned set
* @param toElement high endpoint (exclusive) of the returned set
* @return a view of the portion of this set whose elements range from
* fromElement, inclusive, to toElement, exclusive
* @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 and this set does
* not permit null elements
* @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.
*/
NavigableSet The returned set will throw an IllegalArgumentException
* on an attempt to insert an element outside its range.
*
* @param toElement high endpoint (exclusive) of the returned set
* @return a view of the portion of this set whose elements are strictly
* less than toElement
* @throws ClassCastException if toElement is not compatible
* with this set's comparator (or, if the set has no comparator,
* if toElement does not implement {@link 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 and
* this set does not permit null elements
* @throws IllegalArgumentException if this set itself has a
* restricted range, and toElement lies outside the
* bounds of the range
*/
NavigableSet The returned set will throw an IllegalArgumentException
* on an attempt to insert an element outside its range.
*
* @param fromElement low endpoint (inclusive) of the returned set
* @return a view of the portion of this set whose elements are greater
* than or equal to fromElement
* @throws ClassCastException if fromElement is not compatible
* with this set's comparator (or, if the set has no comparator,
* if fromElement does not implement {@link 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
* and this set does not permit null elements
* @throws IllegalArgumentException if this set itself has a
* restricted range, and fromElement lies outside the
* bounds of the range
*/
NavigableSet