20.7 Hello XML | Java Examples in a Nutshell, 3rd Edition

The JSP 2.0 example (Example 20-5) looks much cleaner than the original JSP code of Example 20-4. Because of its <%@page...%> and <%@taglib...%> directives, however, it is not a valid XML document. JSP 2.0 pages can also be written as valid XML documents using a slightly different format illustrated in Example 20-6. hello3.jspx (note the file extension) is a rewrite of Example 20-5 using the XML format. It is a valid XML file that, when accessed, outputs a valid XHTML document. It uses the <jsp:directive.page> tag instead of the @page directive, and it uses a custom <tags:xhtml> tag to output an appropriate XHTML DOCTYPE declaration and <html> tag. The definition of this custom <tags:xhtml> tag is in the WEB-INF/tags/ directory of the WAR file, and is not shown here. We'll see more about JSP 2 custom tags later in this chapter.

Example 20-6. hello3.jspx

<?xml version="1.0"?> <tags:xhtml xmlns:tags="urn:jsptagdir:/WEB-INF/tags"             xmlns:jsp="http://java.sun.com/JSP/Page"             xmlns:c="http://java.sun.com/jsp/jstl/core"             xmlns="http://www.w3.org/1999/xhtml"> <jsp:directive.page contentType='text/html'/> <head><title>Hello</title></head>   <body>     <c:choose>       <c:when test='${param.name == null}'>         <form action="hello3.jspx">         <p>Please enter your name:         <input name="name"/>         <input type="submit"/>         </p></form>       </c:when>       <c:otherwise>         <p>Hello ${param.name}!</p>       </c:otherwise>     </c:choose>   </body> </tags:xhtml>