- // XMLReaderFactory.java - factory for creating a new reader.
- // Written by David Megginson, sax@megginson.com
- // NO WARRANTY! This class is in the Public Domain.
-
- // $Id: XMLReaderFactory.java,v 1.2 2001/04/05 00:52:32 edwingo Exp $
-
- package org.xml.sax.helpers;
- import org.xml.sax.Parser;
- import org.xml.sax.XMLReader;
- import org.xml.sax.SAXException;
-
-
- /**
- * Factory for creating an XML reader.
- *
- * <blockquote>
- * <em>This module, both source code and documentation, is in the
- * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
- * </blockquote>
- *
- * <p>This class contains static methods for creating an XML reader
- * from an explicit class name, or for creating an XML reader based
- * on the value of the <code>org.xml.sax.driver</code> system
- * property:</p>
- *
- * <pre>
- * try {
- * XMLReader myReader = XMLReaderFactory.createXMLReader();
- * } catch (SAXException e) {
- * System.err.println(e.getMessage());
- * }
- * </pre>
- *
- * <p>Note that these methods will not be usable in environments where
- * system properties are not accessible or where the application or
- * applet is not permitted to load classes dynamically.</p>
- *
- * <p><strong>Note to implementors:</strong> SAX implementations in specialized
- * environments may replace this class with a different one optimized for the
- * environment, as long as its method signatures remain the same.</p>
- *
- * @since SAX 2.0
- * @author David Megginson,
- * <a href="mailto:sax@megginson.com">sax@megginson.com</a>
- * @version 2.0
- * @see org.xml.sax.XMLReader
- */
- final public class XMLReaderFactory
- {
-
- /**
- * Private constructor.
- *
- * <p>This constructor prevents the class from being instantiated.</p>
- */
- private XMLReaderFactory ()
- {
- }
-
-
- /**
- * Attempt to create an XML reader from a system property.
- *
- * <p>This method uses the value of the system property
- * "org.xml.sax.driver" as the full name of a Java class
- * and tries to instantiate that class as a SAX2
- * XMLReader.</p>
- *
- * <p>Note that many Java interpreters allow system properties
- * to be specified on the command line.</p>
- *
- * @return A new XMLReader.
- * @exception org.xml.sax.SAXException If the value of the
- * "org.xml.sax.driver" system property is null,
- * or if the class cannot be loaded and instantiated.
- * @see #createXMLReader(java.lang.String)
- */
- public static XMLReader createXMLReader ()
- throws SAXException
- {
- String className = System.getProperty("org.xml.sax.driver");
- if (className == null) {
- Parser parser;
- try {
- parser = ParserFactory.makeParser();
- } catch (Exception e) {
- parser = null;
- }
- if (parser == null) {
- throw new
- SAXException("System property org.xml.sax.driver not specified");
- } else {
- return new ParserAdapter(parser);
- }
- } else {
- return createXMLReader(className);
- }
- }
-
-
- /**
- * Attempt to create an XML reader from a class name.
- *
- * <p>Given a class name, this method attempts to load
- * and instantiate the class as an XML reader.</p>
- *
- * @return A new XML reader.
- * @exception org.xml.sax.SAXException If the class cannot be
- * loaded, instantiated, and cast to XMLReader.
- * @see #createXMLReader()
- */
- public static XMLReader createXMLReader (String className)
- throws SAXException
- {
- try {
- // Original SAX code
- // return (XMLReader)(Class.forName(className).newInstance());
-
- return (XMLReader) NewInstance.newInstance(className);
- } catch (ClassNotFoundException e1) {
- throw new SAXException("SAX2 driver class " + className +
- " not found", e1);
- } catch (IllegalAccessException e2) {
- throw new SAXException("SAX2 driver class " + className +
- " found but cannot be loaded", e2);
- } catch (InstantiationException e3) {
- throw new SAXException("SAX2 driver class " + className +
- " loaded but cannot be instantiated (no empty public constructor?)",
- e3);
- } catch (ClassCastException e4) {
- throw new SAXException("SAX2 driver class " + className +
- " does not implement XMLReader", e4);
- }
-
- }
-
- }
-
- // end of XMLReaderFactory.java