Exercise 19-1. Two of the examples in this chapter were designed to parse the
web.xml files (introduced in Chapter 20) that configure web applications. The Tomcat
servlet container uses a file named
tomcat-users.xml to configure its user database.
The file shipped by default with Tomcat 5 looks like this:
<?xml version='1.0' encoding='utf-8'?>
<user username="tomcat" password="tomcat" roles="tomcat"/>
<user username="both" password="tomcat" roles="tomcat,role1"/>
<user username="role1" password="tomcat" roles="role1"/>
Write a program that uses the SAX API to parse the
tomcat-users.xml file and output the values of
the username and roles
attributes of each <user> tag.
Exercise 19-2. Using a DOM parser instead of a SAX parser, write a program that
behaves identically to the program you developed in the previous
Exercise 19-3. Implement the javax.swing.tree.JTreeModel
interface on top of a DOM document tree, so that an XML document can
be displayed in a Swing JTree component. Write a
demonstration program that does this with sample XML files.
Exercise 19-4. The WebAppConfig program of Example 19-2 provides the beginning of a framework for
programmatic manipulation of web.xml
configuration files. Extend this example so that it allows servlets,
URL mappings, and initialization parameters to be added to, edited,
and removed from the file. Provide a command-line or Swing-based
interface to your configuration program.