# Uses of Package
java.util

- Packages that use java.util
  Package | Description
  --- | ---
  java.beans |
  java.lang |
  java.lang.invoke |
  java.math | Provides classes for performing arbitrary-precision integer arithmetic (`BigInteger`) and arbitrary-precision decimal arithmetic (`BigDecimal`).
  java.net |
  java.nio.charset |
  java.text |
  java.util |
  java.util.concurrent | Utility classes commonly useful in concurrent programming.
  java.util.concurrent.locks | Interfaces and classes providing a framework for locking and waiting for conditions that is distinct from built-in synchronization and monitors.
  java.util.function | Functional interfaces provide target types for lambda expressions and method references.
  java.util.stream | Classes to support functional-style operations on streams of elements, such as map-reduce transformations on collections.
  org.netbeans.modules.openide.util |
  org.openide.util | Client API part of the Lookup interfaces.
  org.openide.util.lookup | Support classes for the Registration and `Lookup` extension mechanism.
  org.openide.util.lookup.implspi | Interfaces intended to be used within the NetBeans Platform.

- Classes in java.util used by java.beans
  Class and Description
  EventListener A tagging interface that all event listener interfaces must extend.
  EventListenerProxy An abstract wrapper class for an `EventListener` class which associates a set of additional parameters with the listener.
  EventObject The root class from which all event state objects shall be derived.

- Classes in java.util used by java.lang
  Class and Description
  Comparator A comparison function, which imposes a total ordering on some collection of objects.
  Enumeration An object that implements the Enumeration interface generates a series of elements, one at a time.
  Iterator An iterator over a collection.
  Locale A `Locale` object represents a specific geographical, political, or cultural region.
  Map An object that maps keys to values.
  Properties The `Properties` class represents a persistent set of properties.
  Spliterator An object for traversing and partitioning elements of a source.

- Classes in java.util used by java.lang.invoke
  Class and Description
  List An ordered collection (also known as a sequence).

- Classes in java.util used by java.math
  Class and Description
  Random An instance of this class is used to generate a stream of pseudorandom numbers.

- Classes in java.util used by java.net
  Class and Description
  List An ordered collection (also known as a sequence).
  Map An object that maps keys to values.

- Classes in java.util used by java.nio.charset
  Class and Description
  Locale A `Locale` object represents a specific geographical, political, or cultural region.
  Set A collection that contains no duplicate elements.
  SortedMap A `Map` that further provides a total ordering on its keys.

- Classes in java.util used by java.text
  Class and Description
  Calendar The `Calendar` class is an abstract class that provides methods for converting between a specific instant in time and a set of `calendar fields` such as `YEAR`, `MONTH`, `DAY_OF_MONTH`, `HOUR`, and so on, and for manipulating the calendar fields, such as getting the date of the next week.
  Currency Represents a currency.
  Date The class `Date` represents a specific instant in time, with millisecond precision.
  Locale A `Locale` object represents a specific geographical, political, or cultural region.
  Map An object that maps keys to values.
  Set A collection that contains no duplicate elements.
  TimeZone `TimeZone` represents a time zone offset, and also figures out daylight savings.

- Classes in java.util used by java.util
  Class and Description
  AbstractCollection This class provides a skeletal implementation of the `Collection` interface, to minimize the effort required to implement this interface.
  AbstractList This class provides a skeletal implementation of the `List` interface to minimize the effort required to implement this interface backed by a "random access" data store (such as an array).
  AbstractMap This class provides a skeletal implementation of the `Map` interface, to minimize the effort required to implement this interface.
  AbstractQueue This class provides skeletal implementations of some `Queue` operations.
  AbstractSequentialList This class provides a skeletal implementation of the `List` interface to minimize the effort required to implement this interface backed by a "sequential access" data store (such as a linked list).
  AbstractSet This class provides a skeletal implementation of the `Set` interface to minimize the effort required to implement this interface.
  ArrayDeque Resizable-array implementation of the `Deque` interface.
  ArrayList Resizable-array implementation of the `List` interface.
  BitSet This class implements a vector of bits that grows as needed.
  Calendar The `Calendar` class is an abstract class that provides methods for converting between a specific instant in time and a set of `calendar fields` such as `YEAR`, `MONTH`, `DAY_OF_MONTH`, `HOUR`, and so on, and for manipulating the calendar fields, such as getting the date of the next week.
  Collection The root interface in the collection hierarchy.
  Comparator A comparison function, which imposes a total ordering on some collection of objects.
  Currency Represents a currency.
  Date The class `Date` represents a specific instant in time, with millisecond precision.
  Deque A linear collection that supports element insertion and removal at both ends.
  Dictionary The `Dictionary` class is the abstract parent of any class, such as `Hashtable`, which maps keys to values.
  DoubleSummaryStatistics A state object for collecting statistics such as count, min, max, sum, and average.
  Enumeration An object that implements the Enumeration interface generates a series of elements, one at a time.
  EnumMap A specialized `Map` implementation for use with enum type keys.
  EnumSet A specialized `Set` implementation for use with enum types.
  EventListener A tagging interface that all event listener interfaces must extend.
  HashMap Hash table based implementation of the `Map` interface.
  HashSet This class implements the `Set` interface, backed by a hash table (actually a `HashMap` instance).
  Hashtable This class implements a hash table, which maps keys to values.
  IntSummaryStatistics A state object for collecting statistics such as count, min, max, sum, and average.
  Iterator An iterator over a collection.
  List An ordered collection (also known as a sequence).
  ListIterator An iterator for lists that allows the programmer to traverse the list in either direction, modify the list during iteration, and obtain the iterator's current position in the list.
  Locale A `Locale` object represents a specific geographical, political, or cultural region.
  Locale.Category Enum for locale categories.
  LongSummaryStatistics A state object for collecting statistics such as count, min, max, sum, and average.
  Map An object that maps keys to values.
  Map.Entry A map entry (key-value pair).
  NavigableMap A `SortedMap` extended with navigation methods returning the closest matches for given search targets.
  NavigableSet A `SortedSet` extended with navigation methods reporting closest matches for given search targets.
  Optional
  OptionalDouble A container object which may or may not contain a `double` value.
  OptionalInt A container object which may or may not contain a `int` value.
  OptionalLong A container object which may or may not contain a `long` value.
  PrimitiveIterator A base type for primitive specializations of `Iterator`.
  PrimitiveIterator.OfDouble An Iterator specialized for `double` values.
  PrimitiveIterator.OfInt An Iterator specialized for `int` values.
  PrimitiveIterator.OfLong An Iterator specialized for `long` values.
  PriorityQueue An unbounded priority queue based on a priority heap.
  Properties The `Properties` class represents a persistent set of properties.
  Queue A collection designed for holding elements prior to processing.
  Random An instance of this class is used to generate a stream of pseudorandom numbers.
  RandomAccess Marker interface used by `List` implementations to indicate that they support fast (generally constant time) random access.
  ResourceBundle Resource bundles contain locale-specific objects.
  ResourceBundle.Control `ResourceBundle.Control` defines a set of callback methods that are invoked by the `ResourceBundle.getBundle` factory methods during the bundle loading process.
  ServiceLoader A simple service-provider loading facility.
  Set A collection that contains no duplicate elements.
  SortedMap A `Map` that further provides a total ordering on its keys.
  SortedSet A `Set` that further provides a total ordering on its elements.
  Spliterator An object for traversing and partitioning elements of a source.
  Spliterator.OfDouble A Spliterator specialized for `double` values.
  Spliterator.OfInt A Spliterator specialized for `int` values.
  Spliterator.OfLong A Spliterator specialized for `long` values.
  Spliterator.OfPrimitive A Spliterator specialized for primitive values.
  StringJoiner `StringJoiner` is used to construct a sequence of characters separated by a delimiter and optionally starting with a supplied prefix and ending with a supplied suffix.
  TimerTask A task that can be scheduled for one-time or repeated execution by a Timer.
  TimeZone `TimeZone` represents a time zone offset, and also figures out daylight savings.
  Vector The `Vector` class implements a growable array of objects.

- Classes in java.util used by java.util.concurrent
  Class and Description
  AbstractCollection This class provides a skeletal implementation of the `Collection` interface, to minimize the effort required to implement this interface.
  AbstractMap This class provides a skeletal implementation of the `Map` interface, to minimize the effort required to implement this interface.
  AbstractQueue This class provides skeletal implementations of some `Queue` operations.
  AbstractSet This class provides a skeletal implementation of the `Set` interface to minimize the effort required to implement this interface.
  Collection The root interface in the collection hierarchy.
  Comparator A comparison function, which imposes a total ordering on some collection of objects.
  Deque A linear collection that supports element insertion and removal at both ends.
  Iterator An iterator over a collection.
  List An ordered collection (also known as a sequence).
  ListIterator An iterator for lists that allows the programmer to traverse the list in either direction, modify the list during iteration, and obtain the iterator's current position in the list.
  Map An object that maps keys to values.
  Map.Entry A map entry (key-value pair).
  NavigableMap A `SortedMap` extended with navigation methods returning the closest matches for given search targets.
  NavigableSet A `SortedSet` extended with navigation methods reporting closest matches for given search targets.
  Queue A collection designed for holding elements prior to processing.
  Random An instance of this class is used to generate a stream of pseudorandom numbers.
  RandomAccess Marker interface used by `List` implementations to indicate that they support fast (generally constant time) random access.
  Set A collection that contains no duplicate elements.
  SortedMap A `Map` that further provides a total ordering on its keys.
  SortedSet A `Set` that further provides a total ordering on its elements.

- Classes in java.util used by java.util.concurrent.locks
  Class and Description
  Collection The root interface in the collection hierarchy.
  Date The class `Date` represents a specific instant in time, with millisecond precision.

- Classes in java.util used by java.util.function
  Class and Description
  Comparator A comparison function, which imposes a total ordering on some collection of objects.

- Classes in java.util used by java.util.stream
  Class and Description
  Collection The root interface in the collection hierarchy.
  Comparator A comparison function, which imposes a total ordering on some collection of objects.
  DoubleSummaryStatistics A state object for collecting statistics such as count, min, max, sum, and average.
  IntSummaryStatistics A state object for collecting statistics such as count, min, max, sum, and average.
  Iterator An iterator over a collection.
  List An ordered collection (also known as a sequence).
  LongSummaryStatistics A state object for collecting statistics such as count, min, max, sum, and average.
  Map An object that maps keys to values.
  Optional
  OptionalDouble A container object which may or may not contain a `double` value.
  OptionalInt A container object which may or may not contain a `int` value.
  OptionalLong A container object which may or may not contain a `long` value.
  PrimitiveIterator.OfDouble An Iterator specialized for `double` values.
  PrimitiveIterator.OfInt An Iterator specialized for `int` values.
  PrimitiveIterator.OfLong An Iterator specialized for `long` values.
  Set A collection that contains no duplicate elements.
  Spliterator An object for traversing and partitioning elements of a source.
  Spliterator.OfDouble A Spliterator specialized for `double` values.
  Spliterator.OfInt A Spliterator specialized for `int` values.
  Spliterator.OfLong A Spliterator specialized for `long` values.

- Classes in java.util used by org.netbeans.modules.openide.util
  Class and Description
  Set A collection that contains no duplicate elements.

- Classes in java.util used by org.openide.util
  Class and Description
  Collection The root interface in the collection hierarchy.
  EventListener A tagging interface that all event listener interfaces must extend.
  EventObject The root class from which all event state objects shall be derived.
  Set A collection that contains no duplicate elements.

- Classes in java.util used by org.openide.util.lookup
  Class and Description
  Collection The root interface in the collection hierarchy.

- Classes in java.util used by org.openide.util.lookup.implspi
  Class and Description
  Set A collection that contains no duplicate elements.

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