Oracle Application Server 10g Essentials

Chapter 10. XML Development

EXtensible Markup Language (XML) is a metamarkup language for text documents that allows you to store information in a self-describing format. With XML, you organize information by surrounding it with user-defined, human-readable tags, similar to those used in HTML, but not limited to the tag names used by HTML. Instead, tag names are chosen that best describe the information they organize. XML organizes information hierarchically. In addition, the character set used to encode an XML document is specified within the document. Combined, these features make XML a universal format for information exchange.

This chapter starts with a brief introduction to XML. Next, it introduces the various relevant XML standards that exist and examines the support Oracle Application Server provides for these standards. We cover the support in various programming languages such as C, C++, Java, and PL/SQL. Then we include an overview of the XML tools that Oracle Application Server provides for XML development. The chapter finishes up with a glimpse at how some of the Oracle Application Server components employ the use of XML.

XML, DTDs, and XML Schemas

For an XML document to be used for information exchange, it must be parseable, and to be parseable, it must be well-formed . A well-formed document, among other rules, must have an end tag for every start tag, and different start and end tags may not be placed in such a matter as to cross each other’s boundaries.

For instance, ...