diff options
Diffstat (limited to 'libjava/org/xml/sax/helpers/XMLReaderFactory.java')
| -rw-r--r-- | libjava/org/xml/sax/helpers/XMLReaderFactory.java | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/libjava/org/xml/sax/helpers/XMLReaderFactory.java b/libjava/org/xml/sax/helpers/XMLReaderFactory.java new file mode 100644 index 00000000000..9443b27dcca --- /dev/null +++ b/libjava/org/xml/sax/helpers/XMLReaderFactory.java @@ -0,0 +1,136 @@ +// 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 1.1 2000/10/02 02:43:20 sboag 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 {
+ return (XMLReader)(Class.forName(className).newInstance());
+ } 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
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