Java Xml 简明教程
Java DOM4J Parser - Overview
DOM4J 是一个基于 Java 的开源库，用于解析 XML 文档。它是一个高度灵活且内存高效的 API。它经过 Java 优化，并使用 Java 集合，如 List 和 Arrays。
DOM4J is an open source, Java-based library to parse XML documents. It is a highly flexible and memory-efficient API. It is Java-optimized and uses Java collections like List and Arrays.
DOM4J 与 DOM、SAX、XPath 和 XSLT 配合使用。它可以用非常小的内存占用解析大型 XML 文档。
DOM4J works with DOM, SAX, XPath, and XSLT. It can parse large XML documents with very low memory footprint.
Environment Setup
为了使用 DOM4J 解析器，您应该在应用程序的类路径中包含 dom4j-2.1.4.jar。您可以从 here. 下载 jar 文件。
In order to use DOM4J parser, you should have dom4j-2.1.4.jar in your application’s classpath. You can download the jar file from here.
When to Use DOM4J?
以下情况时，您应使用 DOM4J 解析器：
You should use a DOM4J parser when −
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You need to know a lot about the structure of an XML document.
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You need to move parts of an XML document around (you might want to sort certain elements, for example).
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You need to use the information in an XML document more than once.
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You are a Java developer and want to leverage Java-optimized parsing of XML.
What is the Result of Parsing?
当您使用 DOM4J 解析器解析 XML 文档时，您可以灵活地获取包含文档所有元素的树结构，而不会影响应用程序的内存占用。
When you parse an XML document with a DOM4J parser, you get the flexibility to get back a tree structure that contains all of the elements of your document without impacting the memory footprint of the application.
DOM4J 提供了各种实用函数，您可以使用它们来检查 XML 文档的内容和结构。XPath 表达式也可用于在 XML 文档中导航。
DOM4J provides a variety of utility functions that you can use to examine the contents and structure of an XML document. XPath expressions can also be used to navigate through an XML document.
Advantages
以下是一些 DOM4J 的优点：
Following are some advantages of DOM4J −
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Flexible and easily maintainable
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Open source, lightweight and quick API
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Random access of elements is possible