| Collection<E> | Collection is the root of the collection hierarchy. |
| Comparator<T> | A Comparator is used to compare two objects to determine their ordering with
respect to each other. |
| 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 sequence of objects, such as a collection. |
| List<E> | A List is a collection which maintains an ordering for its elements. |
| ListIterator<E> | An ListIterator is used to sequence over a List of objects. |
| Map<K, V> | A Map is a data structure consisting of a set of keys and values
in which each key is mapped to a single value. |
| Map.Entry<K, V> | Map.Entry is a key/value mapping contained in a Map. |
| 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. |
| 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 Set is a data structure which does not allow duplicate elements. |
| SortedMap<K, V> | A map that has its keys ordered. |
| SortedSet<E> | SortedSet is a Set which iterates over its elements in a sorted order. |
| 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 | Date represents a specific moment in time, to the millisecond. |
| Dictionary<K, V> | Note: Do not use this class since it is obsolete. |
| 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
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. |
| 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. |
| Observable | Observable is used to notify a group of Observer objects when a change occurs. |
| 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. |
| Stack<E> | Stack is a Last-In/First-Out(LIFO) data structure which represents a
stack of objects. |
| StringTokenizer | Breaks a string into tokens; new code should probably use split(String). |
| Timer | Timers schedule one-shot or recurring tasks for execution. |
| TimerTask | The TimerTask class represents a task to run at a specified time. |
| 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. |
| 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. |
| Formatter.BigDecimalLayoutForm | The enumeration giving the available styles for formatting very large decimal numbers. |
| 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 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. |
| 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. |
| ServiceConfigurationError | Thrown when a service provider can't be loaded by ServiceLoader. |