Package Summary
Utility classes commonly useful in concurrent programming.
Functional interfaces provide target types for lambda expressions and method references.
Provides classes for reading and writing the JAR (Java ARchive) file format, which is based on the standard ZIP file format with an optional manifest file.
Provides the classes and interfaces of the Java
TM 2 platform's core logging facilities.
This package allows applications to store and retrieve user and system preference and configuration data.
Classes for matching character sequences against patterns specified by regular expressions.
Service provider classes for the classes in the java.util package.
Classes to support functional-style operations on streams of elements, such as map-reduce transformations on collections.
Provides classes for reading and writing the standard ZIP and GZIP file formats.
Interface Summary
The root interface in the
collection hierarchy.
A comparison function, which imposes a
total ordering on some collection of objects.
A linear collection that supports element insertion and removal at both ends.
An object that implements the Enumeration interface generates a series of elements, one at a time.
A tagging interface that all event listener interfaces must extend.
The
Formattable interface must be implemented by any class that needs to perform custom formatting using the
's' conversion specifier of
Formatter.
An iterator over a collection.
An ordered collection (also known as a
sequence).
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.
An object that maps keys to values.
A map entry (key-value pair).
A
SortedMap extended with navigation methods returning the closest matches for given search targets.
A
SortedSet extended with navigation methods reporting closest matches for given search targets.
A class can implement the
Observer interface when it wants to be informed of changes in observable objects.
A base type for primitive specializations of
Iterator.
An Iterator specialized for
double values.
An Iterator specialized for
int values.
An Iterator specialized for
long values.
A collection designed for holding elements prior to processing.
Marker interface used by
List implementations to indicate that they support fast (generally constant time) random access.
A collection that contains no duplicate elements.
A
Map that further provides a
total ordering on its keys.
A
Set that further provides a
total ordering on its elements.
An object for traversing and partitioning elements of a source.
A Spliterator specialized for
double values.
A Spliterator specialized for
int values.
A Spliterator specialized for
long values.
A Spliterator specialized for primitive values.
Class Summary
This class provides a skeletal implementation of the
Collection interface, to minimize the effort required to implement this interface.
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).
This class provides a skeletal implementation of the
Map interface, to minimize the effort required to implement this interface.
An Entry maintaining a key and a value.
An Entry maintaining an immutable key and value.
This class provides skeletal implementations of some
Queue operations.
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).
This class provides a skeletal implementation of the
Set interface to minimize the effort required to implement this interface.
Resizable-array implementation of the
Deque interface.
Resizable-array implementation of the
List interface.
This class contains various methods for manipulating arrays (such as sorting and searching).
This class consists exclusively of static methods for obtaining encoders and decoders for the Base64 encoding scheme.
This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
This class implements a vector of bits that grows as needed.
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.
Calendar.Builder is used for creating a
Calendar from various date-time parameters.
This class consists exclusively of static methods that operate on or return collections.
The class
Date represents a specific instant in time, with millisecond precision.
The
Dictionary class is the abstract parent of any class, such as
Hashtable, which maps keys to values.
A state object for collecting statistics such as count, min, max, sum, and average.
A specialized
Map implementation for use with enum type keys.
A specialized
Set implementation for use with enum types.
An abstract wrapper class for an
EventListener class which associates a set of additional parameters with the listener.
The root class from which all event state objects shall be derived.
An interpreter for printf-style format strings.
GregorianCalendar is a concrete subclass of
Calendar and provides the standard calendar system used by most of the world.
Hash table based implementation of the
Map interface.
This class implements the
Set interface, backed by a hash table (actually a
HashMap instance).
This class implements a hash table, which maps keys to values.
This class implements the
Map interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values).
A state object for collecting statistics such as count, min, max, sum, and average.
Hash table and linked list implementation of the
Map interface, with predictable iteration order.
Hash table and linked list implementation of the
Set interface, with predictable iteration order.
Doubly-linked list implementation of the
List and
Deque interfaces.
ListResourceBundle is an abstract subclass of
ResourceBundle that manages resources for a locale in a convenient and easy to use list.
A
Locale object represents a specific geographical, political, or cultural region.
Builder is used to build instances of
Locale from values configured by the setters.
A state object for collecting statistics such as count, min, max, sum, and average.
This class consists of
static utility methods for operating on objects.
This class represents an observable object, or "data" in the model-view paradigm.
A container object which may or may not contain a non-null value.
A container object which may or may not contain a
double value.
A container object which may or may not contain a
int value.
A container object which may or may not contain a
long value.
An unbounded priority
queue based on a priority heap.
The
Properties class represents a persistent set of properties.
This class is for property permissions.
PropertyResourceBundle is a concrete subclass of
ResourceBundle that manages resources for a locale using a set of static strings from a property file.
An instance of this class is used to generate a stream of pseudorandom numbers.
Resource bundles contain locale-specific objects.
ResourceBundle.Control defines a set of callback methods that are invoked by the
ResourceBundle.getBundle factory methods during the bundle loading process.
A simple text scanner which can parse primitive types and strings using regular expressions.
A simple service-provider loading facility.
SimpleTimeZone is a concrete subclass of
TimeZone that represents a time zone for use with a Gregorian calendar.
An abstract
Spliterator.OfDouble that implements
trySplit to permit limited parallelism.
An abstract
Spliterator.OfInt that implements
trySplit to permit limited parallelism.
An abstract
Spliterator.OfLong that implements
trySplit to permit limited parallelism.
An abstract
Spliterator that implements
trySplit to permit limited parallelism.
A generator of uniform pseudorandom values applicable for use in (among other contexts) isolated parallel computations that may generate subtasks.
The
Stack class represents a last-in-first-out (LIFO) stack of objects.
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.
The string tokenizer class allows an application to break a string into tokens.
A facility for threads to schedule tasks for future execution in a background thread.
A task that can be scheduled for one-time or repeated execution by a Timer.
TimeZone represents a time zone offset, and also figures out daylight savings.
A class that represents an immutable universally unique identifier (UUID).
The
Vector class implements a growable array of objects.
Hash table based implementation of the
Map interface, with
weak keys.
Enum Summary
Enum for
BigDecimal formatting.
Enum for locale categories.
This enum provides constants to select a filtering mode for locale matching.
Exception Summary
This exception may be thrown by methods that have detected concurrent modification of an object when such modification is not permissible.
Unchecked exception thrown when duplicate flags are provided in the format specifier.
Thrown by methods in the
Stack class to indicate that the stack is empty.
Unchecked exception thrown when a conversion and flag are incompatible.
Unchecked exception thrown when the formatter has been closed.
Unchecked exception thrown when the argument corresponding to the format specifier is of an incompatible type.
Unchecked exception thrown when a format string contains an illegal syntax or a format specifier that is incompatible with the given arguments.
Unchecked exception thrown when an illegal combination flags is given.
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.
Unchecked exception thrown when the format width is a negative value other than
-1 or is otherwise unsupported.
Thrown by methods in
Locale and
Locale.Builder to indicate that an argument is not a well-formed BCP 47 tag.
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.
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.
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.
Unchecked exception thrown when the format width is required.
Signals that a resource is missing.
Thrown by various accessor methods to indicate that the element being requested does not exist.
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.
Unchecked exception thrown when an unknown conversion is given.
Unchecked exception thrown when an unknown flag is given.
Error Summary
Error thrown when something goes wrong while loading a service provider.
Package java.util Description
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).
Package Specification
Related Documentation
For overviews, tutorials, examples, guides, and tool documentation, please see:
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Since:
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JDK1.0