Java Reference
In-Depth Information
•
Implementation classes
:Theframeworkprovidesclassesthatprovidedifferent
core interface implementations to address performance and other requirements.
•
Utility classes
: The framework provides utility classes whose methods let you
sort arrays, obtain synchronized collections, and perform other operations.
Thecoreinterfacesinclude
java.lang.Iterable
,
Collection
,
List
,
Set
,
SortedSet
,
NavigableSet
,
Queue
,
Deque
,
Map
,
SortedMap
, and
Navig-
ableMap
.
Collection
extends
Iterable
;
List
,
Set
, and
Queue
each extend
Collection
;
SortedSet
extends
Set
;
NavigableSet
extends
SortedSet
;
Deque
extends
Queue
;
SortedMap
extends
Map
; and
NavigableMap
extends
SortedMap
.
Figure 5-1
illustrates the core interfaces hierarchy (arrows point to parent interfaces).
Figure 5-1.
The Collections Framework is based on a hierarchy of core interfaces.
The framework's implementation classes include
ArrayList
,
LinkedList
,
TreeSet
,
HashSet
,
LinkedHashSet
,
EnumSet
,
PriorityQueue
,
Ar-
rayDeque
,
TreeMap
,
HashMap
,
LinkedHashMap
,
IdentityHashMap
,
WeakHashMap
,and
EnumMap
.Thenameofeachconcreteclassendsinacoreinter-
face name, identifying the core interface on which it is based.
Note
Additional implementation classes are part of the concurrency utilities.