SAX was developed by the members of the XML-DEV mailing list, and the Java version is now a Source Forge project (see Related topics ).The purpose of the project was to provide a more natural means for working with XML -- in other words, one that did not involve the overhead and conceptual leap required for the DOM. The parser sends events, such as the start or end of an element, to an event handler, which processes the information.This tutorial examines the use of the Simple API for XML version 2.0.x, or SAX 2.0.x.It is aimed at developers who have an understanding of XML and wish to learn this lightweight, event-based API for working with XML data.It's not unusual for large files to completely overrun a system's capacity.In addition, creating a DOM tree can be a very slow process.
This means you need to specifically instantiate the handler object, so I'll give a quick overview of that, in case you're not used to working with objects. You can create an error handler just as you created a content handler.For instance, the same document used as an example in How SAX processing works would be represented as nodes, shown here: The rectangular boxes represent element nodes, and the ovals represent text nodes. First, because the tree is persistent in memory, it can be modified so an application can make changes to the data and the structure.It can also work its way up and down the tree at any time, as opposed to the one-shot deal of SAX. On the other hand, a lot of overhead is involved in building these trees in memory.In fact, most parsers used to create DOM trees are actually using SAX to do it!This tutorial demonstrates the construction of an application that uses SAX to tally the responses from a group of users asked to take a survey regarding their alien abduction experiences. XMLReader; public class Survey Reader extends Default Handler happen, but there is, of course, always the chance of problems with the data that you're trying to parse.