// XMLReaderAdapter.java - adapt an SAX2 XMLReader to a SAX1 Parser
// Written by David Megginson, sax@megginson.com
// NO WARRANTY! This class is in the public domain.
// $Id: XMLReaderAdapter.java 225904 2001-05-20 03:12:59Z curcuru $
package org.xml.sax.helpers;
import java.io.IOException;
import java.util.Locale;
import org.xml.sax.Parser; // deprecated
import org.xml.sax.Locator;
import org.xml.sax.InputSource;
import org.xml.sax.AttributeList; // deprecated
import org.xml.sax.EntityResolver;
import org.xml.sax.DTDHandler;
import org.xml.sax.DocumentHandler; // deprecated
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXNotSupportedException;
/**
* Adapt a SAX2 XMLReader as a SAX1 Parser.
*
* <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 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.</p>
*
* @since SAX 2.0
* @author David Megginson,
* <a href="mailto:sax@megginson.com">sax@megginson.com</a>
* @version 2.0r2pre
* @see org.xml.sax.Parser
* @see org.xml.sax.XMLReader
*/
public class XMLReaderAdapter implements Parser, ContentHandler
{
////////////////////////////////////////////////////////////////////
// Constructor.
////////////////////////////////////////////////////////////////////
/**
* Create a new adapter.
*
* <p>Use the "org.xml.sax.driver" property to locate the SAX2
* driver to embed.</p>
*
* @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.
*
* <p>Create a new adapter, wrapped around a SAX2 XMLReader.
* The adapter will make the XMLReader act like a SAX1
* Parser.</p>
*
* @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.
*
* <p>This is not supported in SAX2, and will always throw
* an exception.</p>
*
* @param The locale for error reporting.
* @see org.xml.sax.Parser#setLocale
*/
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
*/
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
*/
public void setDTDHandler (DTDHandler handler)
{
xmlReader.setDTDHandler(handler);
}
/**
* Register the SAX1 document event handler.
*
* <p>Note that the SAX1 document handler has no Namespace
* support.</p>
*
* @param handler The new SAX1 document event handler.
* @see org.xml.sax.Parser#setDocumentHandler
*/
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
*/
public void setErrorHandler (ErrorHandler handler)
{
xmlReader.setErrorHandler(handler);
}
/**
* Parse the document.
*
* <p>This method will throw an exception if the embedded
* XMLReader does not support the
* http://xml.org/sax/features/namespace-prefixes property.</p>
*
* @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)
*/
public void parse (String systemId)
throws IOException, SAXException
{
parse(new InputSource(systemId));
}
/**
* Parse the document.
*
* <p>This method will throw an exception if the embedded
* XMLReader does not support the
* http://xml.org/sax/features/namespace-prefixes property.</p>
*
* @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)
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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)
*/
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)
*/
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)
*/
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)
*/
public String getValue (String qName)
{
return attributes.getValue(qName);
}
private Attributes attributes;
}
}
// end of XMLReaderAdapter.java