This class provides a skeletal implementation of the
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. Typically, the returned set will, in turn, be implemented atop
AbstractSet. This set should not support the
remove methods, and its iterator should not support the
To implement a modifiable map, the programmer must additionally override this class's
put method (which otherwise throws an
UnsupportedOperationException), and the iterator returned by
entrySet().iterator() must additionally implement its
The programmer should generally provide a void (no argument) and map constructor, as per the recommendation in the
Map interface specification.
The documentation for each non-abstract method in this class describes its implementation in detail. Each of these methods may be overridden if the map being implemented admits a more efficient implementation.
This class is a member of the Java Collections Framework .