| java.util |
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:
@since JDK1.0
|
| Java Source File Name | Type | Comment |
| AbstractCollection.java | Class | This class provides a skeletal implementation of the Collection
interface, to minimize the effort required to implement this interface. |
| AbstractList.java | Class | 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.java | Class | This class provides a skeletal implementation of the Map
interface, to minimize the effort required to implement this interface.
To implement an unmodifiable map, the programmer needs only to extend this
class and provide an implementation for the entrySet method, which
returns a set-view of the map's mappings. |
| AbstractQueue.java | Class | This class provides skeletal implementations of some
Queue operations. |
| AbstractSequentialList.java | Class | 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.java | Class | This class provides a skeletal implementation of the Set
interface to minimize the effort required to implement this
interface. |
| ArrayDeque.java | Class | Resizable-array implementation of the
Deque interface. |
| ArrayList.java | Class | Resizable-array implementation of the List interface. |
| Arrays.java | Class | This class contains various methods for manipulating arrays (such as
sorting and searching). |
| BitSet.java | Class | This class implements a vector of bits that grows as needed. |
| Calendar.java | Class | The Calendar class is an abstract class that provides methods
for converting between a specific instant in time and a set of
Calendar.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. |
| Collection.java | Interface | The root interface in the collection hierarchy. |
| Collections.java | Class | This class consists exclusively of static methods that operate on or return
collections. |
| Comparator.java | Interface | A comparison function, which imposes a total ordering on some
collection of objects. |
| ConcurrentModificationException.java | Class | This exception may be thrown by methods that have detected concurrent
modification of an object when such modification is not permissible.
For example, it is not generally permissible for one thread to modify a Collection
while another thread is iterating over it. |
| Currency.java | Class | Represents a currency. |
| Date.java | Class | The class Date represents a specific instant
in time, with millisecond precision.
Prior to JDK 1.1, the class Date had two additional
functions. |
| Deque.java | Interface | A linear collection that supports element insertion and removal at
both ends. |
| Dictionary.java | Class | The Dictionary class is the abstract parent of any
class, such as Hashtable, which maps keys to values. |
| DuplicateFormatFlagsException.java | Class | Unchecked exception thrown when duplicate flags are provided in the format
specifier. |
| EmptyStackException.java | Class | Thrown by methods in the Stack class to indicate
that the stack is empty. |
| Enumeration.java | Interface | An object that implements the Enumeration interface generates a
series of elements, one at a time. |
| EnumMap.java | Class | A specialized
Map implementation for use with enum type keys. |
| EnumSet.java | Class | A specialized
Set implementation for use with enum types. |
| EventListener.java | Interface | A tagging interface that all event listener interfaces must extend. |
| EventListenerProxy.java | Class | An abstract wrapper class for an EventListener class which associates a set
of additional parameters with the listener. |
| EventObject.java | Class |
The root class from which all event state objects shall be derived. |
| FormatFlagsConversionMismatchException.java | Class | Unchecked exception thrown when a conversion and flag are incompatible. |
| Formattable.java | Interface | The Formattable interface must be implemented by any class that
needs to perform custom formatting using the 's' conversion
specifier of
java.util.Formatter . |
| FormattableFlags.java | Class | FomattableFlags are passed to the
Formattable.formatToFormattable.formatTo() method and modify the output format for
. |
| Formatter.java | Class | An interpreter for printf-style format strings. |
| FormatterClosedException.java | Class | Unchecked exception thrown when the formatter has been closed. |
| GregorianCalendar.java | Class | GregorianCalendar is a concrete subclass of
Calendar and provides the standard calendar system
used by most of the world.
GregorianCalendar is a hybrid calendar that
supports both the Julian and Gregorian calendar systems with the
support of a single discontinuity, which corresponds by default to
the Gregorian date when the Gregorian calendar was instituted
(October 15, 1582 in some countries, later in others). |
| HashMap.java | Class | Hash table based implementation of the Map interface. |
| HashSet.java | Class | This class implements the Set interface, backed by a hash table
(actually a HashMap instance). |
| Hashtable.java | Class | |
| IdentityHashMap.java | Class | This class implements the Map interface with a hash table, using
reference-equality in place of object-equality when comparing keys (and
values). |
| IllegalFormatCodePointException.java | Class | Unchecked exception thrown when a character with an invalid Unicode code
point as defined by
Character.isValidCodePoint is passed to the
Formatter . |
| IllegalFormatConversionException.java | Class | Unchecked exception thrown when the argument corresponding to the format
specifier is of an incompatible type. |
| IllegalFormatException.java | Class | Unchecked exception thrown when a format string contains an illegal syntax
or a format specifier that is incompatible with the given arguments. |
| IllegalFormatFlagsException.java | Class | Unchecked exception thrown when an illegal combination flags is given. |
| IllegalFormatPrecisionException.java | Class | 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.java | Class | Unchecked exception thrown when the format width is a negative value other
than -1 or is otherwise unsupported. |
| InputMismatchException.java | Class | 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. |
| InvalidPropertiesFormatException.java | Class | 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.
Note, that although InvalidPropertiesFormatException inherits Serializable
interface from Exception, it is not intended to be Serializable. |
| Iterator.java | Interface | An iterator over a collection. |
| JapaneseImperialCalendar.java | Class | JapaneseImperialCalendar implements a Japanese
calendar system in which the imperial era-based year numbering is
supported from the Meiji era. |
| JumboEnumSet.java | Class | Private implementation class for EnumSet, for "jumbo" enum types
(i.e., those with more than 64 elements). |
| LinkedHashMap.java | Class | Hash table and linked list implementation of the Map interface,
with predictable iteration order. |
| LinkedHashSet.java | Class | Hash table and linked list implementation of the Set interface,
with predictable iteration order. |
| LinkedList.java | Class | Linked list implementation of the List interface. |
| List.java | Interface | An ordered collection (also known as a sequence). |
| ListIterator.java | Interface | 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. |
| ListResourceBundle.java | Class | ListResourceBundle is an abstract subclass of
ResourceBundle that manages resources for a locale
in a convenient and easy to use list. |
| Locale.java | Class | A Locale object represents a specific geographical, political,
or cultural region. |
| LocaleISOData.java | Class | |
| Map.java | Interface | An object that maps keys to values. |
| MissingFormatArgumentException.java | Class | 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.java | Class | Unchecked exception thrown when the format width is required. |
| MissingResourceException.java | Class | Signals that a resource is missing. |
| NavigableMap.java | Interface | A
SortedMap extended with navigation methods returning the
closest matches for given search targets. |
| NavigableSet.java | Interface | A
SortedSet extended with navigation methods reporting
closest matches for given search targets. |
| NoSuchElementException.java | Class | Thrown by the nextElement method of an
Enumeration to indicate that there are no more
elements in the enumeration. |
| Observable.java | Class | This class represents an observable object, or "data"
in the model-view paradigm. |
| Observer.java | Interface | A class can implement the Observer interface when it
wants to be informed of changes in observable objects. |
| PriorityQueue.java | Class | An unbounded priority
based on a priority heap.
The elements of the priority queue are ordered according to their
, or by a
Comparator provided at queue construction time, depending on which constructor is
used. |
| Properties.java | Class | The Properties class represents a persistent set of
properties. |
| PropertyPermission.java | Class | This class is for property permissions.
The name is the name of the property ("java.home",
"os.name", etc). |
| PropertyResourceBundle.java | Class | PropertyResourceBundle is a concrete subclass of
ResourceBundle that manages resources for a locale
using a set of static strings from a property file. |
| Queue.java | Interface | A collection designed for holding elements prior to processing.
Besides basic
java.util.Collection Collection operations,
queues provide additional insertion, extraction, and inspection
operations. |
| Random.java | Class | An instance of this class is used to generate a stream of
pseudorandom numbers. |
| RandomAccess.java | Interface | Marker interface used by List implementations to indicate that
they support fast (generally constant time) random access. |
| RegularEnumSet.java | Class | Private implementation class for EnumSet, for "regular sized" enum types
(i.e., those with 64 or fewer enum constants). |
| ResourceBundle.java | Class | Resource bundles contain locale-specific objects.
When your program needs a locale-specific resource,
a String for example, your program can load it
from the resource bundle that is appropriate for the
current user's locale. |
| Scanner.java | Class | A simple text scanner which can parse primitive types and strings using
regular expressions.
A Scanner breaks its input into tokens using a
delimiter pattern, which by default matches whitespace. |
| ServiceConfigurationError.java | Class | Error thrown when something goes wrong while loading a service provider.
This error will be thrown in the following situations:
- The format of a provider-configuration file violates the specification;
- An
java.io.IOException IOException occurs while reading a
provider-configuration file;
- A concrete provider class named in a provider-configuration file
cannot be found;
- A concrete provider class is not a subclass of the service class;
- A concrete provider class cannot be instantiated; or
- Some other kind of error occurs.
|
| ServiceLoader.java | Class | A simple service-provider loading facility.
A service is a well-known set of interfaces and (usually
abstract) classes. |
| Set.java | Interface | A collection that contains no duplicate elements. |
| SimpleTimeZone.java | Class | SimpleTimeZone is a concrete subclass of TimeZone
that represents a time zone for use with a Gregorian calendar.
The class holds an offset from GMT, called raw offset, and start
and end rules for a daylight saving time schedule. |
| SortedMap.java | Interface | A
Map that further provides a total ordering on its keys.
The map is ordered according to the
of its keys, or by a
Comparator typically
provided at sorted map creation time. |
| SortedSet.java | Interface | A
Set that further provides a total ordering on its elements.
The elements are ordered using their
, or by a
Comparator typically provided at sorted
set creation time. |
| Stack.java | Class | The Stack class represents a last-in-first-out
(LIFO) stack of objects. |
| StringTokenizer.java | Class | The string tokenizer class allows an application to break a
string into tokens. |
| Timer.java | Class | A facility for threads to schedule tasks for future execution in a
background thread. |
| TimerTask.java | Class | A task that can be scheduled for one-time or repeated execution by a Timer. |
| TimeZone.java | Class | TimeZone represents a time zone offset, and also figures out daylight
savings.
Typically, you get a TimeZone using getDefault
which creates a TimeZone based on the time zone where the program
is running. |
| TooManyListenersException.java | Class |
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.
The presence of a "throws TooManyListenersException" clause on any given
concrete implementation of the normally multicast "void addXyzEventListener"
event listener registration pattern is used to annotate that interface as
implementing a unicast Listener special case, that is, that one and only
one Listener may be registered on the particular event listener source
concurrently.
See Also: java.util.EventObject
See Also: java.util.EventListener
version:
1.20 07/05/05
author:
Laurence P. |
| TreeMap.java | Class | A Red-Black tree based
NavigableMap implementation.
The map is sorted according to the
of its keys, or by a
Comparator provided at map
creation time, depending on which constructor is used.
This implementation provides guaranteed log(n) time cost for the
containsKey, get, put and remove
operations. |
| TreeSet.java | Class | A
NavigableSet implementation based on a
TreeMap .
The elements are ordered using their
, or by a
Comparator provided at set creation
time, depending on which constructor is used.
This implementation provides guaranteed log(n) time cost for the basic
operations (
add ,
remove and
contains ).
Note that the ordering maintained by a set (whether or not an explicit
comparator is provided) must be consistent with equals if it is to
correctly implement the
Set interface. |
| UnknownFormatConversionException.java | Class | Unchecked exception thrown when an unknown conversion is given. |
| UnknownFormatFlagsException.java | Class | Unchecked exception thrown when an unknown flag is given. |
| UUID.java | Class | A class that represents an immutable universally unique identifier (UUID).
A UUID represents a 128-bit value.
There exist different variants of these global identifiers. |
| Vector.java | Class | The
Vector class implements a growable array of
objects. |
| WeakHashMap.java | Class | A hashtable-based Map implementation with weak keys.
An entry in a WeakHashMap will automatically be removed when
its key is no longer in ordinary use. |
| XMLUtils.java | Class | A class used to aid in Properties load and save in XML. |