JavaServer Pages, 3rd Edition

Writing JSP Pages as XML Documents

An important part of JSP 2.0 is the added flexibility for writing JSP pages as well-formed, namespace-aware XML documents. Such JSP pages are referred to as JSP Documents, to distinguish them from the type of plain JSP pages described in the rest of this book. Tag files, described in Chapter 11, can also be written as XML documents. While all examples in this section show JSP Documents, you should be aware that everything said about JSP Documents also applies to tag files in XML format.

The main differences between a plain JSP page and a JSP Document are:

• Template data and JSP elements, taken together, must form a well-formed XML document, which optionally can be validated. This means, among other things, that XML element equivalents must be used instead of the regular JSP directive and scripting elements.

• A JSP Document is initially processed as a namespace aware XML document, meaning that standard XML entity resolution applies, page encoding determination is performed as defined by the XML specification, namespace declarations are honored and apply to both JSP elements and template data elements, XML quoting rules apply (special characters in attribute values and text nodes must be encoded), etc.

• Whitespace is processed in the same manner as when XSLT is used to process an XML document. That is, text nodes that contain only whitespace are dropped, except for text nodes in the body of a <jsp:text> element (where whitespace is preserved).

• An XML declaration ...