In the next chapter, we take a look at a technology that allows XML to be used as a data format in an important request and response model: XML-RPC. XML Remote Procedure Calls allow clients in a distributed system to request that tasks be executed on a server (or servers) on another portion of the network. Until recently, RPC has declined in popularity, mostly due to the surge of RMI-based technologies in the Java space (most notably, EJB). However, with XML as a data format, XML-RPC is a new solution for many problems that could not be solved cleanly or efficiently without RPC. We take a look at XML-RPC next, and in particular, at the Java libraries available.
2. Stylebook is a project that handles generation of very complex documents, including HTML, and is used to generate the Cocoon documentation and web site. The Stylebook project is set to integrate with Cocoon in Cocoon 2.0.
3. Although the 3.1 build is used in these examples, Cocoon only requires a 2.x version of the servlet API. In addition, configuration options in Tomcat should not be subject to change with revisions of the engine; in other words, the instructions within this chapter should apply to any 3.x version of Tomcat.
4. This is a drastic
oversimplification; the JSP is actually precompiled into a servlet, and a
PrintWriteractually handles output. For more
information on JSP, refer to Java Servlet Programming,
by Jason Hunter (O'Reilly & Associates).
5. Additionally, there are some rare
occurrences where the 1.7.x version of the Cocoon engine has problems loading
a logicsheet from a
file:// reference. Using the
resource:// alternative is a way to
be sure you avoid these problems.