+ * This module, both source code and documentation, is in the + * Public Domain, and comes with NO WARRANTY. + * See http://www.saxproject.org + * for further information. + *+ * + *
This class wraps a SAX2 {@link org.xml.sax.XMLReader XMLReader} + * and makes it act as a SAX1 {@link org.xml.sax.Parser Parser}. The XMLReader + * must support a true value for the + * http://xml.org/sax/features/namespace-prefixes property or parsing will fail + * with a {@link org.xml.sax.SAXException SAXException}; if the XMLReader + * supports a false value for the http://xml.org/sax/features/namespaces + * property, that will also be used to improve efficiency.
+ * + * @since SAX 2.0 + * @author David Megginson + * @version 2.0.1 (sax2r2) + * @see org.xml.sax.Parser + * @see org.xml.sax.XMLReader + */ +public class XMLReaderAdapter implements Parser, ContentHandler +{ + + + //////////////////////////////////////////////////////////////////// + // Constructor. + //////////////////////////////////////////////////////////////////// + + + /** + * Create a new adapter. + * + *Use the "org.xml.sax.driver" property to locate the SAX2 + * driver to embed.
+ * + * @exception org.xml.sax.SAXException If the embedded driver + * cannot be instantiated or if the + * org.xml.sax.driver property is not specified. + */ + public XMLReaderAdapter () + throws SAXException + { + setup(XMLReaderFactory.createXMLReader()); + } + + + /** + * Create a new adapter. + * + *Create a new adapter, wrapped around a SAX2 XMLReader. + * The adapter will make the XMLReader act like a SAX1 + * Parser.
+ * + * @param xmlReader The SAX2 XMLReader to wrap. + * @exception java.lang.NullPointerException If the argument is null. + */ + public XMLReaderAdapter (XMLReader xmlReader) + { + setup(xmlReader); + } + + + + /** + * Internal setup. + * + * @param xmlReader The embedded XMLReader. + */ + private void setup (XMLReader xmlReader) + { + if (xmlReader == null) { + throw new NullPointerException("XMLReader must not be null"); + } + this.xmlReader = xmlReader; + qAtts = new AttributesAdapter(); + } + + + + //////////////////////////////////////////////////////////////////// + // Implementation of org.xml.sax.Parser. + //////////////////////////////////////////////////////////////////// + + + /** + * Set the locale for error reporting. + * + *This is not supported in SAX2, and will always throw + * an exception.
+ * + * @param locale the locale for error reporting. + * @see org.xml.sax.Parser#setLocale + * @exception org.xml.sax.SAXException Thrown unless overridden. + */ + @Override + public void setLocale (Locale locale) + throws SAXException + { + throw new SAXNotSupportedException("setLocale not supported"); + } + + + /** + * Register the entity resolver. + * + * @param resolver The new resolver. + * @see org.xml.sax.Parser#setEntityResolver + */ + @Override + public void setEntityResolver (EntityResolver resolver) + { + xmlReader.setEntityResolver(resolver); + } + + + /** + * Register the DTD event handler. + * + * @param handler The new DTD event handler. + * @see org.xml.sax.Parser#setDTDHandler + */ + @Override + public void setDTDHandler (DTDHandler handler) + { + xmlReader.setDTDHandler(handler); + } + + + /** + * Register the SAX1 document event handler. + * + *Note that the SAX1 document handler has no Namespace + * support.
+ * + * @param handler The new SAX1 document event handler. + * @see org.xml.sax.Parser#setDocumentHandler + */ + @Override + public void setDocumentHandler (DocumentHandler handler) + { + documentHandler = handler; + } + + + /** + * Register the error event handler. + * + * @param handler The new error event handler. + * @see org.xml.sax.Parser#setErrorHandler + */ + @Override + public void setErrorHandler (ErrorHandler handler) + { + xmlReader.setErrorHandler(handler); + } + + + /** + * Parse the document. + * + *This method will throw an exception if the embedded + * XMLReader does not support the + * http://xml.org/sax/features/namespace-prefixes property.
+ * + * @param systemId The absolute URL of the document. + * @exception java.io.IOException If there is a problem reading + * the raw content of the document. + * @exception org.xml.sax.SAXException If there is a problem + * processing the document. + * @see #parse(org.xml.sax.InputSource) + * @see org.xml.sax.Parser#parse(java.lang.String) + */ + @Override + public void parse (String systemId) + throws IOException, SAXException + { + parse(new InputSource(systemId)); + } + + + /** + * Parse the document. + * + *This method will throw an exception if the embedded + * XMLReader does not support the + * http://xml.org/sax/features/namespace-prefixes property.
+ * + * @param input An input source for the document. + * @exception java.io.IOException If there is a problem reading + * the raw content of the document. + * @exception org.xml.sax.SAXException If there is a problem + * processing the document. + * @see #parse(java.lang.String) + * @see org.xml.sax.Parser#parse(org.xml.sax.InputSource) + */ + @Override + public void parse (InputSource input) + throws IOException, SAXException + { + setupXMLReader(); + xmlReader.parse(input); + } + + + /** + * Set up the XML reader. + */ + private void setupXMLReader () + throws SAXException + { + xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true); + try { + xmlReader.setFeature("http://xml.org/sax/features/namespaces", + false); + } catch (SAXException e) { + // NO OP: it's just extra information, and we can ignore it + } + xmlReader.setContentHandler(this); + } + + + + //////////////////////////////////////////////////////////////////// + // Implementation of org.xml.sax.ContentHandler. + //////////////////////////////////////////////////////////////////// + + + /** + * Set a document locator. + * + * @param locator The document locator. + * @see org.xml.sax.ContentHandler#setDocumentLocator + */ + @Override + public void setDocumentLocator (Locator locator) + { + if (documentHandler != null) + documentHandler.setDocumentLocator(locator); + } + + + /** + * Start document event. + * + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#startDocument + */ + @Override + public void startDocument () + throws SAXException + { + if (documentHandler != null) + documentHandler.startDocument(); + } + + + /** + * End document event. + * + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#endDocument + */ + @Override + public void endDocument () + throws SAXException + { + if (documentHandler != null) + documentHandler.endDocument(); + } + + + /** + * Adapt a SAX2 start prefix mapping event. + * + * @param prefix The prefix being mapped. + * @param uri The Namespace URI being mapped to. + * @see org.xml.sax.ContentHandler#startPrefixMapping + */ + @Override + public void startPrefixMapping (String prefix, String uri) + { + } + + + /** + * Adapt a SAX2 end prefix mapping event. + * + * @param prefix The prefix being mapped. + * @see org.xml.sax.ContentHandler#endPrefixMapping + */ + @Override + public void endPrefixMapping (String prefix) + { + } + + + /** + * Adapt a SAX2 start element event. + * + * @param uri The Namespace URI. + * @param localName The Namespace local name. + * @param qName The qualified (prefixed) name. + * @param atts The SAX2 attributes. + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#endDocument + */ + @Override + public void startElement (String uri, String localName, + String qName, Attributes atts) + throws SAXException + { + if (documentHandler != null) { + qAtts.setAttributes(atts); + documentHandler.startElement(qName, qAtts); + } + } + + + /** + * Adapt a SAX2 end element event. + * + * @param uri The Namespace URI. + * @param localName The Namespace local name. + * @param qName The qualified (prefixed) name. + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#endElement + */ + @Override + public void endElement (String uri, String localName, + String qName) + throws SAXException + { + if (documentHandler != null) + documentHandler.endElement(qName); + } + + + /** + * Adapt a SAX2 characters event. + * + * @param ch An array of characters. + * @param start The starting position in the array. + * @param length The number of characters to use. + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#characters + */ + @Override + public void characters (char ch[], int start, int length) + throws SAXException + { + if (documentHandler != null) + documentHandler.characters(ch, start, length); + } + + + /** + * Adapt a SAX2 ignorable whitespace event. + * + * @param ch An array of characters. + * @param start The starting position in the array. + * @param length The number of characters to use. + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#ignorableWhitespace + */ + @Override + public void ignorableWhitespace (char ch[], int start, int length) + throws SAXException + { + if (documentHandler != null) + documentHandler.ignorableWhitespace(ch, start, length); + } + + + /** + * Adapt a SAX2 processing instruction event. + * + * @param target The processing instruction target. + * @param data The remainder of the processing instruction + * @exception org.xml.sax.SAXException The client may raise a + * processing exception. + * @see org.xml.sax.ContentHandler#processingInstruction + */ + @Override + public void processingInstruction (String target, String data) + throws SAXException + { + if (documentHandler != null) + documentHandler.processingInstruction(target, data); + } + + + /** + * Adapt a SAX2 skipped entity event. + * + * @param name The name of the skipped entity. + * @see org.xml.sax.ContentHandler#skippedEntity + * @exception org.xml.sax.SAXException Throwable by subclasses. + */ + @Override + public void skippedEntity (String name) + throws SAXException + { + } + + + + //////////////////////////////////////////////////////////////////// + // Internal state. + //////////////////////////////////////////////////////////////////// + + XMLReader xmlReader; + DocumentHandler documentHandler; + AttributesAdapter qAtts; + + + + //////////////////////////////////////////////////////////////////// + // Internal class. + //////////////////////////////////////////////////////////////////// + + + /** + * Internal class to wrap a SAX2 Attributes object for SAX1. + */ + final class AttributesAdapter implements AttributeList + { + AttributesAdapter () + { + } + + + /** + * Set the embedded Attributes object. + * + * @param The embedded SAX2 Attributes. + */ + void setAttributes (Attributes attributes) + { + this.attributes = attributes; + } + + + /** + * Return the number of attributes. + * + * @return The length of the attribute list. + * @see org.xml.sax.AttributeList#getLength + */ + @Override + public int getLength () + { + return attributes.getLength(); + } + + + /** + * Return the qualified (prefixed) name of an attribute by position. + * + * @return The qualified name. + * @see org.xml.sax.AttributeList#getName + */ + @Override + public String getName (int i) + { + return attributes.getQName(i); + } + + + /** + * Return the type of an attribute by position. + * + * @return The type. + * @see org.xml.sax.AttributeList#getType(int) + */ + @Override + public String getType (int i) + { + return attributes.getType(i); + } + + + /** + * Return the value of an attribute by position. + * + * @return The value. + * @see org.xml.sax.AttributeList#getValue(int) + */ + @Override + public String getValue (int i) + { + return attributes.getValue(i); + } + + + /** + * Return the type of an attribute by qualified (prefixed) name. + * + * @return The type. + * @see org.xml.sax.AttributeList#getType(java.lang.String) + */ + @Override + public String getType (String qName) + { + return attributes.getType(qName); + } + + + /** + * Return the value of an attribute by qualified (prefixed) name. + * + * @return The value. + * @see org.xml.sax.AttributeList#getValue(java.lang.String) + */ + @Override + public String getValue (String qName) + { + return attributes.getValue(qName); + } + + private Attributes attributes; + } + +} + +// end of XMLReaderAdapter.java