Validating sax parser
This takes considerable time and space for large documents (memory allocation and data-structure construction take time).
This works well so far, but I want to check more than only the well-formedness of the given file and use validation via an XSD Scheme, which also contains default values for optional attributes. Your Content Handler will be notified of default values for optional attributes. Unfortunately, I'm still having problems with my implementation, since my parser does not accept my validator as content handler. If it uses some custom mechanism, you may have to do a "prepass" reading (some of) the source file to discover the schema, then reading it again with the Validator Handler in place. Sun's implementation supports any combination of configuration options.(If a combination is not supported by a particular implementation, it is required to generate a factory configuration error.) Although a full treatment of XML Schema is beyond the scope of this tutorial, this section shows you the steps you take to validate an XML document using an existing schema written in the XML Schema language.In addition, the following must be true: You'll learn more about namespaces in Validating with XML Schema.
uses the non-validating parser by default, but it can also activate validation.
Because of the event-driven nature of SAX, processing documents is generally far faster than DOM-style parsers, so long as the processing can be done in a start-to-end pass.
Many tasks, such as indexing, conversion to other formats, very simple formatting, and the like, can be done that way.
Although the phrase "XML Schema schema" would be precise, we'll use the phrase "XML Schema definition" to avoid the appearance of redundancy.
To be notified of validation errors in an XML document, the parser factory must be configured to create a validating parser, as shown in the preceding section.
(To learn more about XML Schema, you can review the online tutorial, Note: There are multiple schema-definition languages, including RELAX NG, Schematron, and the W3C "XML Schema" standard.