Package java.util

Interface Summary

Interface	Description
Collection<E>	The root interface in the collection hierarchy.
Comparator<T>	A comparison function, which imposes a total ordering on some collection of objects.
Deque<E>	A linear collection that supports element insertion and removal at both ends.
Enumeration<E>	A legacy iteration interface.
EventListener	EventListener is the superclass of all event listener interfaces.
Formattable	Classes that handle custom formatting for the 's' specifier of Formatter should implement the Formattable interface.
Iterator<E>	An iterator over a collection.
List<E>	An ordered collection (also known as a sequence).
ListIterator<E>	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<K,V>	An object that maps keys to 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	Observer is the interface to be implemented by objects that receive notification of updates on an Observable object.
PrimitiveIterator<T,T_CONS>	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.
Queue<E>	A collection designed for holding elements prior to processing.
RandomAccess	RandomAccess is implemented by List implementations that support fast (usually constant time) random access.
Set<E>	A collection that contains no duplicate elements.
SortedMap<K,V>	A Map that further provides a total ordering on its keys.
SortedSet<E>	A Set that further provides a total ordering on its elements.
Spliterator<T>	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<T,T_CONS,T_SPLITR extends Spliterator.OfPrimitive<T,T_CONS,T_SPLITR>>	A Spliterator specialized for primitive values.

Class Summary

Class	Description
AbstractCollection<E>	Class AbstractCollection is an abstract implementation of the Collection interface.
AbstractList<E>	AbstractList is an abstract implementation of the List interface, optimized for a backing store which supports random access.
AbstractMap<K,V>	A base class for Map implementations.
AbstractMap.SimpleEntry<K,V>	A key-value mapping with mutable values.
AbstractMap.SimpleImmutableEntry<K,V>	An immutable key-value mapping.
AbstractQueue<E>	This class provides skeletal implementations of some Queue operations.
AbstractSequentialList<E>	AbstractSequentialList is an abstract implementation of the List interface.
AbstractSet<E>	An AbstractSet is an abstract implementation of the Set interface.
ArrayDeque<E>	Resizable-array implementation of the Deque interface.
ArrayList<E>	ArrayList is an implementation of List, backed by an array.
Arrays	Arrays contains static methods which operate on arrays.
BitSet	The BitSet class implements a bit array.
Calendar	Calendar is an abstract base class for converting between a Date object and a set of integer fields such as YEAR, MONTH, DAY, HOUR, and so on.
Collections	Collections contains static methods which operate on Collection classes.
Currency	A currency corresponding to an ISO 4217 currency code such as "EUR" or "USD".
Date	A specific moment in time, with millisecond precision.
Dictionary<K,V>	Note: Do not use this class since it is obsolete.
DoubleSummaryStatistics	A state object for collecting statistics such as count, min, max, sum, and average.
EnumMap<K extends Enum<K>,V>	An Map specialized for use with Enum types as keys.
EnumSet<E extends Enum<E>>	An EnumSet is a specialized Set to be used with enums as keys.
EventListenerProxy	This abstract class provides a simple wrapper for objects of type EventListener.
EventObject	EventObjects represent events.
FormattableFlags	FormattableFlags are used as a parameter to Formattable.formatTo(Formatter, int, int, int) and change the output format in Formattables.
Formatter	Formats arguments according to a format string (like printf in C).
GregorianCalendar	GregorianCalendar is a concrete subclass of Calendar and provides the standard calendar used by most of the world.
HashMap<K,V>	HashMap is an implementation of Map.
HashSet<E>	HashSet is an implementation of a Set.
Hashtable<K,V>	Hashtable is a synchronized implementation of Map.
IdentityHashMap<K,V>	IdentityHashMap is a variant on HashMap which tests equality by reference instead of equality by value.
IntSummaryStatistics	A state object for collecting statistics such as count, min, max, sum, and average.
LinkedHashMap<K,V>	LinkedHashMap is an implementation of Map that guarantees iteration order.
LinkedHashSet<E>	LinkedHashSet is a variant of HashSet.
LinkedList<E>	LinkedList is an implementation of List, backed by a doubly-linked list.
ListResourceBundle	ListResourceBundle is the abstract superclass of classes which provide resources by implementing the getContents() method to return the list of resources.
Locale	Locale represents a language/country/variant combination.
Locale.Builder	A class that helps construct Locale instances.
LongSummaryStatistics	A state object for collecting statistics such as count, min, max, sum, and average.
Objects	This class consists of static utility methods for operating on objects, or checking certain conditions before operation.
Observable	Observable is used to notify a group of Observer objects when a change occurs.
Optional<T>	A container object which may or may not contain a non-null value.
OptionalDouble	A container object which may or may not contain a double value.
OptionalInt	A container object which may or may not contain an int value.
OptionalLong	A container object which may or may not contain a long value.
PriorityQueue<E>	A PriorityQueue holds elements on a priority heap, which orders the elements according to their natural order or according to the comparator specified at construction time.
Properties	A Properties object is a Hashtable where the keys and values must be Strings.
PropertyPermission	Legacy security code; do not use.
PropertyResourceBundle	PropertyResourceBundle loads resources from an InputStream.
Random	This class provides methods that return pseudo-random values.
ResourceBundle	ResourceBundle is an abstract class which is the superclass of classes which provide Locale-specific resources.
ResourceBundle.Control	ResourceBundle.Control is a static utility class defines ResourceBundle load access methods, its default access order is as the same as before.
Scanner	A parser that parses a text string of primitive types and strings with the help of regular expressions.
ServiceLoader<S>	A service-provider loader.
SimpleTimeZone	SimpleTimeZone is a concrete subclass of TimeZone that represents a time zone for use with a Gregorian calendar.
Spliterators	Static classes and methods for operating on or creating instances of Spliterator and its primitive specializations Spliterator.OfInt, Spliterator.OfLong, and Spliterator.OfDouble.
Spliterators.AbstractDoubleSpliterator	An abstract Spliterator.OfDouble that implements trySplit to permit limited parallelism.
Spliterators.AbstractIntSpliterator	An abstract Spliterator.OfInt that implements trySplit to permit limited parallelism.
Spliterators.AbstractLongSpliterator	An abstract Spliterator.OfLong that implements trySplit to permit limited parallelism.
Spliterators.AbstractSpliterator<T>	An abstract Spliterator that implements trySplit to permit limited parallelism.
Stack<E>	Stack is a Last-In/First-Out(LIFO) data structure which represents a stack of objects.
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.
StringTokenizer	The string tokenizer class allows an application to break a string into tokens.
Timer	Class to schedule tasks in a separate thread.
TimerTask	A task to be scheduled in a Timer.
TimeZone	TimeZone represents a time zone, primarily used for configuring a Calendar or SimpleDateFormat instance.
TreeMap<K,V>	A map whose entries are sorted by their keys.
TreeSet<E>	TreeSet is an implementation of SortedSet.
UnsafeArrayList<T>	An array-backed list that exposes its array.
UUID	UUID is an immutable representation of a 128-bit universally unique identifier (UUID).
Vector<E>	Vector is an implementation of List, backed by an array and synchronized.
WeakHashMap<K,V>	WeakHashMap is an implementation of Map with keys which are WeakReferences.

Enum Summary

Enum	Description
Formatter.BigDecimalLayoutForm	The enumeration giving the available styles for formatting very large decimal numbers.

Exception Summary

Exception	Description
ConcurrentModificationException	An ConcurrentModificationException is thrown when a Collection is modified and an existing iterator on the Collection is used to modify the Collection as well.
DuplicateFormatFlagsException	The unchecked exception will be thrown out if there are duplicate flags given out in the format specifier.
EmptyStackException	An EmptyStackException is thrown if the pop/peek method of a stack is executed on an empty stack.
FormatFlagsConversionMismatchException	A FormatFlagsConversionMismatchException will be thrown if a conversion and the flags are incompatible.
FormatterClosedException	A FormatterClosedException will be thrown if the formatter has been closed.
IllegalFormatCodePointException	An IllegalFormatCodePointException will be thrown if an invalid Unicode code point (defined by Character.isValidCodePoint(int)) is passed as a parameter to a Formatter.
IllegalFormatConversionException	An IllegalFormatConversionException will be thrown when the parameter is incompatible with the corresponding format specifier.
IllegalFormatException	An IllegalFormatException is thrown when a format string that contains either an illegal syntax or format specifier is transferred as a parameter.
IllegalFormatFlagsException	An IllegalFormatFlagsException will be thrown if the combination of the format flags is illegal.
IllegalFormatPrecisionException	An IllegalFormatPrecisionException will be thrown if the precision is a negative other than -1 or in other cases where precision is not supported.
IllegalFormatWidthException	An IllegalFormatWidthException will be thrown if the width is a negative value other than -1 or in other cases where a width is not supported.
IllformedLocaleException	Thrown when a locale subtag or field is not well formed.
InputMismatchException	An InputMismatchException is thrown by a scanner to indicate that the next token does not match or is out of range for the type specified in the pattern.
InvalidPropertiesFormatException	An InvalidPropertiesFormatException is thrown if loading the XML document defining the properties does not follow the Properties specification.
MissingFormatArgumentException	A MissingFormatArgumentException will be thrown if there is no corresponding argument with the specified conversion or an argument index that refers to a missing argument.
MissingFormatWidthException	A MissingFormatWidthException will be thrown if the format width is missing but is required.
MissingResourceException	A MissingResourceException is thrown by ResourceBundle when a resource bundle cannot be found or a resource is missing from a resource bundle.
NoSuchElementException	Thrown when trying to retrieve an element past the end of an Enumeration or Iterator.
TooManyListenersException	A TooManyListenersException is thrown when an attempt is made to add more than one listener to an event source which only supports a single listener.
UnknownFormatConversionException	An UnknownFormatConversionException will be thrown if the format conversion is unknown.
UnknownFormatFlagsException	An UnknownFormatFlagsException will be thrown if there is an unknown flag.

Error Summary

Error	Description
ServiceConfigurationError	Thrown when a service provider can't be loaded by ServiceLoader.