java练习册--集合类.docVIP

文件编号：YM/WI-19 文件版本： A版 文件页码：page of java课程实践指导书 ——JAVA篇 Java中的集合类（2） 一、练习目标: Hashtable 的使用。 二、练习时间与作业要求： 本次练习一共需要180分钟。翻译练习写在JAVA笔记本上，书面作业写在JAVA家庭作业本上。 后面的书面作业不包括在这个时间范围内。 三、翻译练习： 将下面要求翻译的内容，写在记事本上（阴影部分不写出来，要求看懂） java.util Class Hashtable java.lang.Object | +-- HYPERLINK \\server\..\java帮助\java api\java\util\Dictionary.htmljava.util.Dictionary | +--java.util.Hashtable All Implemented Interfaces:  HYPERLINK \\server\..\java帮助\java api\java\lang\Cloneable.htmlCloneable,  HYPERLINK \\server\..\java帮助\java api\java\util\Map.htmlMap,  HYPERLINK \\server\..\java帮助\java api\java\io\Serializable.htmlSerializable Direct Known Subclasses:  HYPERLINK \\server\..\java帮助\java api\java\util\Properties.htmlProperties,  HYPERLINK \\server\..\java帮助\java api\javax\swing\UIDefaults.htmlUIDefaults public class Hashtable extends  HYPERLINK \\server\..\java帮助\java api\java\util\Dictionary.htmlDictionary implements  HYPERLINK \\server\..\java帮助\java api\java\util\Map.htmlMap,  HYPERLINK \\server\..\java帮助\java api\java\lang\Cloneable.htmlCloneable,  HYPERLINK \\server\..\java帮助\java api\java\io\Serializable.htmlSerializable This class implements a hashtable, which maps keys to values. Any non-null object can be used as a key or as a value. To successfully store and retrieve objects from a hashtable, the objects used as keys must implement the hashCode method and the equals method. An instance of Hashtable has two parameters that affect its performance: initial capacity and load factor. The capacity is the number of buckets in the hash table, and the initial capacity is simply the capacity at the time the hash table is created. Note that the hash table is open: in the case a hash collision, a single bucket stores multiple entries, which must be searched sequentially. The load factor is a measure of how full the hash table is allowed to get before its capacity is automatically increased. When the number of entries in the hashtable