/* * Written by Doug Lea and Josh Bloch 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; /** * A {@link SortedSet} extended with navigation methods reporting * closest matches for given search targets. Methods lower}, * {@code floor}, {@code ceiling}, and {@code higher} return elements * respectively less than, less than or equal, greater than or equal, * and greater than a given element, returning {@code null} if there * is no such element. A {@code NavigableSet} may be accessed and * traversed in either ascending or descending order. The {@code * descendingSet} method returns a view of the set with the senses of * all relational and directional methods inverted. The performance of * ascending operations and views is likely to be faster than that of * descending ones. This interface additionally defines methods * {@code pollFirst} and {@code pollLast} that return and remove the * lowest and highest element, if one exists, else returning {@code * null}. Methods {@code subSet}, {@code headSet}, * and {@code tailSet} differ from the like-named {@code * SortedSet} methods in accepting additional arguments describing * whether lower and upper bounds are inclusive versus exclusive. * Subsets of any {@code NavigableSet} must implement the {@code * NavigableSet} interface. * *
The return values of navigation methods may be ambiguous in * implementations that permit {@code null} elements. However, even * in this case the result can be disambiguated by checking * {@code contains(null)}. To avoid such issues, implementations of * this interface are encouraged to not permit insertion of * {@code null} elements. (Note that sorted sets of {@link * Comparable} elements intrinsically do not permit {@code null}.) * *
This interface is a member of the
*
* Java Collections Framework.
*
* @author Doug Lea
* @author Josh Bloch
* @param The returned set will throw an {@code IllegalArgumentException}
* on an attempt to insert an element outside its range.
*
* @param fromElement low endpoint of the returned set
* @param fromInclusive true if the low endpoint ({@code fromElement}) is
* to be included in the returned view
* @param toElement high endpoint of the returned set
* @param toInclusive true if the high endpoint ({@code toElement}) is
* to be included in the returned view
* @return a view of the portion of this set whose elements range from
* {@code fromElement}, inclusive, to {@code toElement}, exclusive
* @throws ClassCastException if {@code fromElement} and
* {@code 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 {@code fromElement} or
* {@code toElement} cannot be compared to elements currently in
* the set.
* @throws NullPointerException if {@code fromElement} or
* {@code toElement} is null and this set does
* not permit null elements
* @throws IllegalArgumentException if {@code fromElement} is
* greater than {@code toElement}; or if this set itself
* has a restricted range, and {@code fromElement} or
* {@code toElement} lies outside the bounds of the range.
*/
NavigableSet The returned set will throw an {@code IllegalArgumentException}
* on an attempt to insert an element outside its range.
*
* @param toElement high endpoint of the returned set
* @param inclusive true if the high endpoint ({@code toElement}) is
* to be included in the returned view
* @return a view of the portion of this set whose elements are less than
* (or equal to, if {@code inclusive} is true) {@code toElement}
* @throws ClassCastException if {@code toElement} is not compatible
* with this set's comparator (or, if the set has no comparator,
* if {@code toElement} does not implement {@link Comparable}).
* Implementations may, but are not required to, throw this
* exception if {@code toElement} cannot be compared to elements
* currently in the set.
* @throws NullPointerException if {@code toElement} is null and
* this set does not permit null elements
* @throws IllegalArgumentException if this set itself has a
* restricted range, and {@code toElement} lies outside the
* bounds of the range
*/
NavigableSet The returned set will throw an {@code IllegalArgumentException}
* on an attempt to insert an element outside its range.
*
* @param fromElement low endpoint of the returned set
* @param inclusive true if the low endpoint ({@code fromElement}) is
* to be included in the returned view
* @return a view of the portion of this set whose elements are greater
* than or equal to {@code fromElement}
* @throws ClassCastException if {@code fromElement} is not compatible
* with this set's comparator (or, if the set has no comparator,
* if {@code fromElement} does not implement {@link Comparable}).
* Implementations may, but are not required to, throw this
* exception if {@code fromElement} cannot be compared to elements
* currently in the set.
* @throws NullPointerException if {@code fromElement} is null
* and this set does not permit null elements
* @throws IllegalArgumentException if this set itself has a
* restricted range, and {@code fromElement} lies outside the
* bounds of the range
*/
NavigableSet