• In TextXML.java, I basically put all the logic in one method.  Yes, I admit, this is very poor object oriented design.  It should really be broken up among multiple methods, and possibly multiple classes.

I also had an inner class to handle errors.

/*
 * TestXML.java
 *
 * Created on May 8, 2003, 4:36 PM
 */

import javax.xml.parsers.*;
import org.w3c.dom.*;
import java.io.*;

/**
 *
 * @author  default
 * @version 
 */
public class TestXML {

    /** Creates new TestXML */
    public TestXML() {
    }

    public void runTest() {
        try {
            // First, read in data from XML file. 
            // We'll hardcode the filename now, but change it to an attribute later.
            File f = new File("datasource.xml");

            // Get a factory. 
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

            // Tell it to validate.
            factory.setValidating(true);

            // Tell it to ignore whitespace.
            factory.setIgnoringElementContentWhitespace(true);

            // Get a builder from the factory.
            DocumentBuilder builder = factory.newDocumentBuilder();

            // Make an instance of the DatasourceErrorHandler.
            DatasourceErrorHandler deh = new DatasourceErrorHandler();

            // Add the ErrorHandler to the builder. 
            builder.setErrorHandler(deh);

            // Parse the doucment
            Document doc = builder.parse(f);

            // Get the root element.
            Element root = doc.getDocumentElement(); 

            // Now get the children of the root element.
            NodeList children = root.getChildNodes();

            // loop through the elements.
            for (int i=0; i < children.getLength(); i++) {

                // Get the child as a node.
                Node child = children.item(i);

                // We shouldn't get any output here for our simple XML file, 
                // but just in case...
                if (child instanceof Text) {
                    System.out.println("Text: " + ((Text) child).getData().trim());
                } else if (child instanceof Element) {

                    // This is certainly not flexible.  But we know from our XML
                    // that, if this is a child, it will only contain text. 
                    // A better way to do this would be a recursive loop with an 
                    // instanceof test.

                    Text textNode = (Text) child.getFirstChild();
                    System.out.println("TextNode: " + textNode.getData().trim());
                }

            }

            // Informational.
            System.out.println("Finished loop");
        } catch (Exception e) {
            // Handle errors.
            System.out.println("Exception in runTest.  Message: " + e.getMessage());
            e.printStackTrace();
        }
    }
 

    public static void main(String args[]) {

            // Create a TestXML object and run the test.
          TestXML txml = new TestXML();
          txml.runTest();
    }

    class DatasourceErrorHandler implements org.xml.sax.ErrorHandler {

        public void error(org.xml.sax.SAXParseException sAXParseException) throws org.xml.sax.SAXException {
            System.out.println("OMG! Error." + sAXParseException.getMessage());
        } 

        public void warning(org.xml.sax.SAXParseException sAXParseException) throws org.xml.sax.SAXException {
            System.out.println("Warning!" + sAXParseException.getMessage());
        } 

        public void fatalError(org.xml.sax.SAXParseException sAXParseException) throws org.xml.sax.SAXException {
            System.out.println("OMG! Fatal Error!" + sAXParseException.getMessage());
        }

    }

}
 
 

• The XML file is quite simple.  I don't have any attributes, but feel free to add some if you'd like.

<?xml version="1.0" ?> 
<!DOCTYPE database SYSTEM "datasource.dtd">

<database>
 <drivername>com.mysql.jdbc.Driver</drivername>
 <databaseURL>jdbc:mysql://localhost/students</databaseURL>
</database>
 

• And the DTD is equally simple.

<!ELEMENT database (drivername, databaseURL)>
<!ELEMENT drivername (#PCDATA)>
<!ELEMENT databaseURL (#PCDATA)>
 

• Go ahead and try it out.  Start from scratch, and refer to this or ask me when you get stuck.  If you have time, add some attributes.