Java and XML, Second Edition

XSP

XSP stands for Extensible Server Pages, and is perhaps the most important development coming out of the Cocoon project. JavaServer Pages (JSP) allows tags and inline Java code to be inserted into an otherwise normal HTML page; when the JSP page is requested, the code is executed and the results are inserted right into the output HTML.^[17] This has taken the Java and ASP worlds by storm, ostensibly simplifying server-side Java programming and allowing a separation of output and logic. However, there are still some significant problems. First, JSP does not really provide a separation of content and presentation. This is the same problem I have been talking about: changes to a banner, font color, or text size require the JSP (with the inline Java and JavaBean references) to be modified. JSP also mingles content (pure data) with presentation in the same way static HTML does. Second, there is no ability to transform the JSP into any other format, or use it across applications, because the JSP specification is designed primarily for delivery of output.

XSP remedies these problems. XSP is simply XML at its heart. Take a look at the sample XSP page in Example 10-7.

Example 10-7. A simple XSP page

<?xml version="1.0"?> <?cocoon-process type="xsp"?> <?cocoon-process type="xslt"?> <?xml-stylesheet href="myStylesheet.xsl" type="text/xsl"?> <xsp:page language="java" xmlns:xsp="http://www.apache.org/1999/XSP/Core" > <xsp:logic> private static int numHits = 0; private synchronized int getNumHits( ...