Package java.util

Utilities

See: Description

Interface Summary

Interface	Description
Collection<E>	Interface that represents a collection of objects.
Comparator<T>	Interface for objects that specify an ordering between objects.
Deque<E>	A linear collection that supports element insertion and removal at both ends.
Enumeration<E>	Interface for lists of objects that can be returned in sequence.
EventListener	Every event in Java implement this interface
Formattable	The Formattable interface is used to provide customised formatting to arbitrary objects via the Formatter.
Iterator<E>	An object which iterates over a collection.
List<E>	An ordered collection (also known as a list).
ListIterator<E>	An extended version of Iterator to support the extra features of Lists.
Map<K,V>	An object that maps keys onto values.
Map.Entry<K,V>	A map entry (key-value pair).
NavigableMap<K,V>	A SortedMap extended with navigation methods returning the closest matches for given search targets.
NavigableSet<E>	A SortedSet extended with navigation methods reporting closest matches for given search targets.
Observer	Interface that is implemented when a class wants to be informed of changes in Observable objects.
Queue<E>	A collection designed for holding elements prior to processing.
RandomAccess	Marker interface used to inform List implementations that they support fast (usually constant time) random access.
Set<E>	A collection that contains no duplicates.
SortedMap<K,V>	A map which guarantees its key's iteration order.
SortedSet<E>	A set which guarantees its iteration order.

Class Summary

Class	Description
AbstractCollection<E>	A basic implementation of most of the methods in the Collection interface to make it easier to create a collection.
AbstractList<E>	A basic implementation of most of the methods in the List interface to make it easier to create a List based on a random-access data structure.
AbstractMap<K,V>	An abstract implementation of Map to make it easier to create your own implementations.
AbstractMap.SimpleEntry<K,V>	A class which implements Map.Entry.
AbstractMap.SimpleImmutableEntry<K,V>	A class containing an immutable key and value.
AbstractQueue<E>	This class provides skeletal implementations of some Queue operations.
AbstractSequentialList<E>	Abstract superclass to make it easier to implement the List interface when backed by a sequential-access store, such as a linked list.
AbstractSet<E>	An abstract implementation of Set to make it easier to create your own implementations.
ArrayDeque<E>	Resizable-array implementation of the Deque interface.
ArrayList<E>	An array-backed implementation of the List interface.
Arrays	This class contains various static utility methods performing operations on arrays, and a method to provide a List "view" of an array to facilitate using arrays with Collection-based APIs.
BitSet	This class can be thought of in two ways.
Calendar	This class is an abstract base class for Calendars, which can be used to convert between Date objects and a set of integer fields which represent YEAR, MONTH, DAY, etc.
Collections	Utility class consisting of static methods that operate on, or return Collections.
Date	This class represents a specific time in milliseconds since the epoch.
Dictionary<K,V>	A Dictionary maps keys to values; how it does that is implementation-specific.
FormattableFlags	This class contains a set of flags used by the Formattable#formatTo() method.
Formatter	A Java formatter for printf-style format strings, as seen in the C programming language.
GregorianCalendar	This class represents the Gregorian calendar, that is used in most countries all over the world.
HashMap<K,V>	This class provides a hashtable-backed implementation of the Map interface.
HashSet<T>	This class provides a HashMap-backed implementation of the Set interface.
Hashtable<K,V>	A class which implements a hashtable data structure.
IdentityHashMap<K,V>	This class provides a hashtable-backed implementation of the Map interface, but uses object identity to do its hashing.
LinkedHashMap<K,V>	This class provides a hashtable-backed implementation of the Map interface, with predictable traversal order.
LinkedHashSet<T>	This class provides a hashtable-backed implementation of the Set interface, with predictable traversal order.
LinkedList<T>	Linked list implementation of the List interface.
Locale	Locales represent a specific country and culture.
Observable	This class represents an object which is observable.
PriorityQueue<E>
Properties	A set of persistent properties, which can be saved or loaded from a stream.
Random	This class generates pseudorandom numbers.
Stack<T>
StringTokenizer	This class splits a string into tokens.
Timer	Timer that can run TimerTasks at a later time.
TimerTask	Task that can be run at a later time if given to a Timer.
TreeMap<K,V>	This class provides a red-black tree implementation of the SortedMap interface.
TreeSet<T>	This class provides a TreeMap-backed implementation of the SortedSet interface.
UUID	This class represents a 128-bit UUID value.
Vector<T>	The Vector classes implements growable arrays of Objects.

Exception Summary

Exception	Description
ConcurrentModificationException	Exception thrown by Iterators if the underlying connection has been modified during the iteration.
EmptyQueueException	An exception thrown by some Queue class methods to indicate that the Queue is empty
EmptyStackException	An exception thrown by some stack class methods to indicate that the stack is empty
MissingResourceException	This exception is thrown when a resource is missing.
NoSuchElementException	NoSuchElementException is a Exception used with StringTokenizer

Package java.util Description

Utilities