[Java] RandomAccess

iteye_5362

于 2008-12-19 13:16:21 发布

阅读量126

点赞数

分类专栏： Java 文章标签： Java performance Access

Java 专栏收录该内容

5 篇文章

订阅专栏

本文解析了RandomAccess接口的作用及其在不同列表实现中的性能优势。该接口作为一种标记接口，旨在标识具备随机访问能力的类，使得泛型算法可以根据列表的具体类型调整行为以优化性能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

RandomAccess is a marker interface. It doesn't define methods; instead, it identifies a class as having a particular capability.

According to the online document:


The primary purpose of this interface is to allow generic algorithms 
to alter their behavior to provide good performance when applied to 
either random or sequential access lists.

To be more specific, for typical instances of the class, this loop:


for (int i=0, n=list.size(); i < n; i++)
     list.get(i);

runs faster than this loop:


for (Iterator i=list.iterator(); i.hasNext(); )
     i.next();

The well-known implementing classes are:

ArrayList, Stack, Vector