Just Java™ 2

Some Rules of XML

XML follows the same kind of hierarchical data structuring rules that apply throughout most programming languages, and therefore XML can represent the same kind of data that we are used to dealing with in our programs. As we'll see later in the chapter, you can always build a tree data structure out of a well-formed XML file and you can always write out a tree into an XML file. When you want to send XML data to someone, the XML file form is handy. When you want to process the data, the in-memory tree-form is handy. The purpose of the Java XML API is to provide classes that make it easy to go from one form to the other, and to grab data on the way.

The XML element

Notice that all XML tags come in matched pairs of a begin ...