Advanced Java Programming

Distributed Computing
XML

XML links

XML "a truly open and well-defined, neutral data format." Enterprise Application Integration

XML is huge in J2EE 1.4. (Some of the alphabet, and more)
Chapter 2: Understanding XML, Chapter 4: Java API for XML Processing, Chapter 5: Simple API for XML, Chapter 8: Building Web Services with JAX-RPC, Chapter 9: SOAP with Attachments API for Java, Chapter 10: Java API for XML Registries

There was only the API tutorial for XML in 1.3 ( Part 1 local), but a lot in 1.4: E.G. Chapter 2. Read this for interesting things like why XML is important.
Main idea/benefit: data interoperability - automating processes without intervention, integrating and distributing

You can have a servlet without a .xml file ( Hall) which many people do for beginning programming with servlets or servlets that do not require other resources.

Marty Hall "Controlling Web Application with web.xml" (Ch. 5 of his book)
Since I know you will not read the chapter ;-) here is an example of using XML in your servlet

Joseph Tappero did a nice web.xml for his submission. Notice

init-param's (can then get from init method)

public class UserLogonForm extends HttpServlet {

	static final long serialVersionUID = 100L;
	static final String drvr = "db.driver";
	static final String durl = "db.url";
	static final String user = "db.username";
	static final String pwrd = "db.password";

 public void init(ServletConfig config) throws ServletException {
        super.init(config);
        
        // retrieve and store the init-params
        ServletContext context = config.getServletContext();
        context.setAttribute(drvr, config.getInitParameter(drvr));
        context.setAttribute(durl, config.getInitParameter(durl));
        context.setAttribute(user, config.getInitParameter(user));
        context.setAttribute(pwrd, config.getInitParameter(pwrd));

servlet-name - actual servlet name
servlet-class (where class (package) is)
servlet-mapping and url-pattern (what user sees)
He used a redirect in his code: response.sendRedirect("http://localhost:8080/SofTrackServlet/SubmissionForm");

Because identifying the data gives you some sense of what it means (how to interpret it, what you should do with it), XML is sometimes described as a mechanism for specifying the semantics (meaning) of the data. ( J2EE tutorial) (used to be at http://java.sun.com/javaee/5/docs/tutorial/doc/Overview5.html but they changed all the link names and organization since I wrote these notes so now I do not know which particular page it was. Sorry!)

and connections to XML

one

Related: the ant build tool - an ant tutorial and access free?

xml.com

FAQs for XML (nice)

www.w3.org/XML

tutorials from google