f you have worked with XML in Java applications during the past few years, you know the pain of parsing and extracting XML data inside the application. The process required writing lots of cumbersome code to retrieve each element from JAXB objects. More importantly, how the application parsed incoming XML was entirely a mystery; many times, my application simply crashed while parsing large XML documents.
I always hoped for an application to make parsing and retrieving XML data simpler and easier, and with the 2004 releases of DOM4J and JDOM, my day finally had come. While both solutions were developed for the same purpose, DOM4J provides more features, such as a provision for parsing large XML documents, memory-efficient parsing, and a variety of utility classes for XML-based enterprise application development.
DOM4J is the product I'd been waiting for. All enterprise Java developers are sure to love it. DOM4J is built on the latest trend of universal tool platforms: an open, extensible tool built for anything and everything.
The DOM4J XML framework's main features include:
- A plug-in for any parser (SAX or DOM)
- Navigation of XML documents with the Java2 collections framework
- Parsing large XML documents with little memory overhead
Besides these, it provides support for the following:
- XPATH integration
- XSLT integration
- Pretty printing XML
- Functionality for comparing nodes
Since DOM4J supports the Java2 collections framework, it provides developers the flexibility to use a variety of utility classes to cater to the performance requirements of their applications. For instance, some may use a LinkedList rather than an ArrayList because its usage characteristics perform better in their scenarios. Others may use a Vector because it is synchronized.
This article demonstrates flexible, high-performance, and memory-efficient implementations of DOM4J for XML parsing and data navigation. It also provides detailed examples of important DOM4J features that address the main hardships of XML-based enterprise application development.