Java.Util Namespace

Classes

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.
AbstractMap.SimpleEntry	An Entry maintaining a key and a value.
AbstractMap.SimpleImmutableEntry	An unmodifiable Entry maintaining a key and a value.
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.
Arrays	This class contains various methods for manipulating arrays (such as sorting and searching).
Base64	This class consists exclusively of static methods for obtaining encoders and decoders for the Base64 encoding scheme.
Base64.Decoder	This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
Base64.Encoder	This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
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 #fields 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.
Calendar.Builder	Calendar.Builder is used for creating a Calendar from various date-time parameters.
Collections	This class consists exclusively of static methods that operate on or return collections.
Comparator
ConcurrentModificationException	This exception may be thrown by methods that have detected concurrent modification of an object when such modification is not permissible.
Currency	Represents a currency.
Date	The class Date represents a specific instant in time, with millisecond precision.
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.
DuplicateFormatFlagsException	Unchecked exception thrown when duplicate flags are provided in the format specifier.
EmptyStackException	Thrown by methods in the Stack class to indicate that the stack is empty.
EnumMap	A specialized Map implementation for use with enum type keys.
EnumSet	A specialized Set implementation for use with enum types.
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.
FormatFlagsConversionMismatchException	Unchecked exception thrown when a conversion and flag are incompatible.
FormattableFlags	FormattableFlags are passed to the Formattable#formatTo Formattable.formatTo() method and modify the output format for Formattable Formattables.
Formatter	An interpreter for printf-style format strings.
Formatter.BigDecimalLayoutForm	Enum for BigDecimal formatting.
FormatterClosedException	Unchecked exception thrown when the formatter has been closed.
GregorianCalendar	GregorianCalendar is a concrete subclass of Calendar and provides the standard calendar system used by most of the world.
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.
HexFormat	HexFormat converts between bytes and chars and hex-encoded strings which may include additional formatting markup such as prefixes, suffixes, and delimiters.
IdentityHashMap	This class implements the Map interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values).
IllegalFormatCodePointException	Unchecked exception thrown when a character with an invalid Unicode code point as defined by Character#isValidCodePoint is passed to the Formatter.
IllegalFormatConversionException	Unchecked exception thrown when the argument corresponding to the format specifier is of an incompatible type.
IllegalFormatException	Unchecked exception thrown when a format string contains an illegal syntax or a format specifier that is incompatible with the given arguments.
IllegalFormatFlagsException	Unchecked exception thrown when an illegal combination flags is given.
IllegalFormatPrecisionException	Unchecked exception thrown when the precision is a negative value other than -1, the conversion does not support a precision, or the value is otherwise unsupported.
IllegalFormatWidthException	Unchecked exception thrown when the format width is a negative value other than -1 or is otherwise unsupported.
IllformedLocaleException	Thrown by methods in Locale and Locale.Builder to indicate that an argument is not a well-formed BCP 47 tag.
InputMismatchException	Thrown by a Scanner to indicate that the token retrieved does not match the pattern for the expected type, or that the token is out of range for the expected type.
IntSummaryStatistics	A state object for collecting statistics such as count, min, max, sum, and average.
InvalidPropertiesFormatException	Thrown to indicate that an operation could not complete because the input did not conform to the appropriate XML document type for a collection of properties, as per the Properties specification.
LinkedHashMap	Hash table and linked list implementation of the Map interface, with predictable iteration order.
LinkedHashSet	Hash table and linked list implementation of the Set interface, with predictable iteration order.
LinkedList	Doubly-linked list implementation of the List and Deque interfaces.
List
ListResourceBundle	ListResourceBundle is an abstract subclass of ResourceBundle that manages resources for a locale in a convenient and easy to use list.
Locale	A Locale object represents a specific geographical, political, or cultural region.
Locale.Builder	Builder is used to build instances of Locale from values configured by the setters.
Locale.Category	Enum for locale categories.
Locale.FilteringMode	This enum provides constants to select a filtering mode for locale matching.
Locale.IsoCountryCode	Enum for specifying the type defined in ISO 3166.
Locale.LanguageRange	This class expresses a <em>Language Range</em> defined in RFC 4647 Matching of Language Tags.
LongSummaryStatistics	A state object for collecting statistics such as count, min, max, sum, and average.
Map
MapEntry
MissingFormatArgumentException	Unchecked exception thrown when there is a format specifier which does not have a corresponding argument or if an argument index refers to an argument that does not exist.
MissingFormatWidthException	Unchecked exception thrown when the format width is required.
MissingResourceException	Signals that a resource is missing.
NoSuchElementException	Thrown by various accessor methods to indicate that the element being requested does not exist.
Objects	This class consists of static utility methods for operating on objects, or checking certain conditions before operation.
Observable	This class represents an observable object, or "data" in the model-view paradigm.
Optional	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	An unbounded priority Queue queue based on a priority heap.
Properties	The Properties class represents a persistent set of properties.
PropertyPermission	Legacy security code; do not use.
PropertyResourceBundle	PropertyResourceBundle is a concrete subclass of ResourceBundle that manages resources for a locale using a set of static strings from a property file.
Random	An instance of this class is used to generate a stream of pseudorandom numbers.
ResourceBundle	Resource bundles contain locale-specific objects.
ResourceBundle.Control	ResourceBundle.Control defines a set of callback methods that are invoked by the ResourceBundle#getBundle(String, Locale, ClassLoader, Control) ResourceBundle.getBundle factory methods during the bundle loading process.
Scanner	A simple text scanner which can parse primitive types and strings using regular expressions.
ServiceConfigurationError	Error thrown when something goes wrong while locating, loading, or instantiating a service provider.
ServiceLoader	A simple service-provider loading facility.
Set
SimpleTimeZone	SimpleTimeZone is a concrete subclass of TimeZone that represents a time zone for use with a Gregorian calendar.
Spliterator
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	An abstract Spliterator that implements trySplit to permit limited parallelism.
Spliterators.AbstractSpliterator.InterfaceConsts
SplittableRandom	A generator of uniform pseudorandom values applicable for use in (among other contexts) isolated parallel computations that may generate subtasks.
Stack	The Stack class represents a last-in-first-out (LIFO) 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	A facility for threads to schedule tasks for future execution in a background thread.
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.
TooManyListenersException	The TooManyListenersException Exception is used as part of the Java Event model to annotate and implement a unicast special case of a multicast Event Source.
TreeMap	A Red-Black tree based NavigableMap implementation.
TreeSet	A NavigableSet implementation based on a TreeMap.
UnknownFormatConversionException	Unchecked exception thrown when an unknown conversion is given.
UnknownFormatFlagsException	Unchecked exception thrown when an unknown flag is given.
UUID	A class that represents an immutable universally unique identifier (UUID).
Vector	The Vector class implements a growable array of objects.
WeakHashMap	Hash table based implementation of the Map interface, with <em>weak keys</em>.

Interfaces

ICollection	The root interface in the collection hierarchy.
IComparator	A comparison function, which imposes a total ordering on some collection of objects.
IDeque	A linear collection that supports element insertion and removal at both ends.
IEnumeration	An object that implements the Enumeration interface generates a series of elements, one at a time.
IEventListener	A tagging interface that all event listener interfaces must extend.
IFormattable	The Formattable interface must be implemented by any class that needs to perform custom formatting using the 's' conversion specifier of java.util.Formatter.
IIterator	An iterator over a collection.
IList	An ordered collection (also known as a sequence).
IListIterator	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.
IMap	An object that maps keys to values.
IMapEntry	A map entry (key-value pair).
INavigableMap	A SortedMap extended with navigation methods returning the closest matches for given search targets.
INavigableSet	A SortedSet extended with navigation methods reporting closest matches for given search targets.
IObserver	A class can implement the Observer interface when it wants to be informed of changes in observable objects.
IPrimitiveIterator	A base type for primitive specializations of Iterator.
IPrimitiveIteratorOfDouble	An Iterator specialized for double values.
IPrimitiveIteratorOfInt	An Iterator specialized for int values.
IPrimitiveIteratorOfLong	An Iterator specialized for long values.
IQueue	A collection designed for holding elements prior to processing.
IRandomAccess	Marker interface used by List implementations to indicate that they support fast (generally constant time) random access.
ISet	A collection that contains no duplicate elements.
ISortedMap	A Map that further provides a <em>total ordering</em> on its keys.
ISortedSet	A Set that further provides a total ordering on its elements.
ISpliterator	An object for traversing and partitioning elements of a source.

Enums

CalendarField	Enumerates values returned by several types and taken as a parameter of several types.
CalendarStyle	Enumerates values returned by several types.
FormatFlags	Enumerates values returned by several types and taken as a parameter of the F:Java.Util.IFormattable.FormatTo member.
SpliteratorCharacteristics
TimeZoneKind	Enumerates values returned by several types.
TimeZoneStyle	Enumerates values returned by several types and taken as a parameter of the F:Java.Util.TimeZone.GetDisplayName, and F:Java.Util.TimeZone.GetDisplayName members.