95-30-025-java.util-AbstractMap

1.世界

1.类图

2.源码解析

This class provides a skeletal implementation of the <tt>Map</tt>
interface, to minimize the effort required to implement this interface.

该类提供Map接口的基本实现，以最小化实现此接口所需的工作。

<p>To implement an unmodifiable map, the programmer needs only to extend this
class and provide an implementation for the <tt>entrySet</tt> method, which
returns a set-view of the map's mappings.  Typically, the returned set
will, in turn, be implemented atop <tt>AbstractSet</tt>.  This set should
not support the <tt>add</tt> or <tt>remove</tt> methods, and its iterator
should not support the <tt>remove</tt> method.

​ 要实现不可修改的映射，程序员只需要扩展这个类并为entrySet方法提供一个实现，该方法返回映射的集视图。通常，返回的集合将依次在AbstractSet之上实现。这个集合不应该支持add或remove方法，它的迭代器也不应该支持remove方法。

<p>To implement a modifiable map, the programmer must additionally override
this class's <tt>put</tt> method (which otherwise throws an
<tt>UnsupportedOperationException</tt>), and the iterator returned by
<tt>entrySet().iterator()</tt> must additionally implement its
<tt>remove</tt> method.

​ 要实现可修改的映射，程序员必须额外覆盖该类的put方法(否则会抛出一个UnsupportedOperationException)，entrySet().iterator()返回的迭代器必须额外实现它的remove方法。

<p>The programmer should generally provide a void (no argument) and map
constructor, as per the recommendation in the <tt>Map</tt> interface
specification.

按照map接口规范中的建议，程序员通常应该提供一个void(无参数)和map构造函数。

<p>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.

该类中每个非抽象方法的文档详细描述了其实现。如果正在实现的映射允许更有效的实现，则可以覆盖这些方法。