| Package | Description | 
|---|---|
| java.util | Contains the collections framework, legacy collection classes, event model,
date and time facilities, internationalization, and miscellaneous utility
classes (a string tokenizer, a random-number generator, and a bit array). | 
| java.util.concurrent | Utility classes commonly useful in concurrent programming. | 
| Modifier and Type | Interface and Description | 
|---|---|
| interface  | NavigableSet<E>A  SortedSetextended with navigation methods reporting
 closest matches for given search targets. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | TreeSet<E>A  NavigableSetimplementation based on aTreeMap. | 
| Modifier and Type | Method and Description | 
|---|---|
| static <E> SortedSet<E> | Collections. checkedSortedSet(SortedSet<E> s,
                Class<E> type)Returns a dynamically typesafe view of the specified sorted set. | 
| static <E> SortedSet<E> | Collections. emptySortedSet()Returns an empty sorted set (immutable). | 
| SortedSet<E> | TreeSet. headSet(E toElement) | 
| SortedSet<E> | SortedSet. headSet(E toElement)Returns a view of the portion of this set whose elements are
 strictly less than toElement. | 
| SortedSet<E> | NavigableSet. headSet(E toElement)Returns a view of the portion of this set whose elements are
 strictly less than toElement. | 
| SortedSet<E> | TreeSet. subSet(E fromElement,
      E toElement) | 
| SortedSet<E> | SortedSet. subSet(E fromElement,
      E toElement)Returns a view of the portion of this set whose elements range
 from fromElement, inclusive, to toElement,
 exclusive. | 
| SortedSet<E> | NavigableSet. subSet(E fromElement,
      E toElement)Returns a view of the portion of this set whose elements range
 from fromElement, inclusive, to toElement,
 exclusive. | 
| static <T> SortedSet<T> | Collections. synchronizedSortedSet(SortedSet<T> s)Returns a synchronized (thread-safe) sorted set backed by the specified
 sorted set. | 
| SortedSet<E> | TreeSet. tailSet(E fromElement) | 
| SortedSet<E> | SortedSet. tailSet(E fromElement)Returns a view of the portion of this set whose elements are
 greater than or equal to fromElement. | 
| SortedSet<E> | NavigableSet. tailSet(E fromElement)Returns a view of the portion of this set whose elements are
 greater than or equal to fromElement. | 
| static <T> SortedSet<T> | Collections. unmodifiableSortedSet(SortedSet<T> s)Returns an unmodifiable view of the specified sorted set. | 
| Modifier and Type | Method and Description | 
|---|---|
| static <E> SortedSet<E> | Collections. checkedSortedSet(SortedSet<E> s,
                Class<E> type)Returns a dynamically typesafe view of the specified sorted set. | 
| static <T> SortedSet<T> | Collections. synchronizedSortedSet(SortedSet<T> s)Returns a synchronized (thread-safe) sorted set backed by the specified
 sorted set. | 
| static <T> SortedSet<T> | Collections. unmodifiableSortedSet(SortedSet<T> s)Returns an unmodifiable view of the specified sorted set. | 
| Constructor and Description | 
|---|
| PriorityQueue(SortedSet<? extends E> c)Creates a  PriorityQueuecontaining the elements in the
 specified sorted set. | 
| TreeSet(SortedSet<E> s)Constructs a new tree set containing the same elements and
 using the same ordering as the specified sorted set. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | ConcurrentSkipListSet<E>A scalable concurrent  NavigableSetimplementation based on
 aConcurrentSkipListMap. | 
| Constructor and Description | 
|---|
| ConcurrentSkipListSet(SortedSet<E> s)Constructs a new set containing the same elements and using the
 same ordering as the specified sorted set. | 
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