javolution.xml.sax.XMLReaderImpl Maven / Gradle / Ivy
/*
* Javolution - Java(TM) Solution for Real-Time and Embedded Systems
* Copyright (C) 2012 - Javolution (http://javolution.org/)
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software is
* freely granted, provided that this notice is preserved.
*/
package javolution.xml.sax;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.net.URL;
import javolution.text.CharArray;
import javolution.xml.internal.stream.XMLStreamReaderImpl;
import javolution.xml.stream.XMLStreamConstants;
import javolution.xml.stream.XMLStreamException;
import org.xml.sax.DTDHandler;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;
/**
* This class provides a real-time SAX2-like XML parser; this parser is
* extremely fast and does not create temporary objects
* (no garbage generated and no GC interruption).
*
* The parser is implemented as a SAX2 wrapper around
* {@link XMLStreamReaderImpl} and share the same characteristics.
*
* Note: This parser is a SAX2-like parser with the
* java.lang.String type replaced by
* {@link CharArray}/{@link CharSequence} in the {@link ContentHandler},
* {@link Attributes} interfaces and {@link DefaultHandler} base class.
* If a standard SAX2 or JAXP parser is required, you may consider using
* the wrapping class {@link SAX2ReaderImpl}. Fast but not as fast as
* java.lang.String instances are dynamically allocated
* while parsing.
*
* @author Jean-Marie Dautelle
* @version 4.0, June 16, 2006
*/
public class XMLReaderImpl implements XMLReader {
/**
* Holds the default handler instance.
*/
private static DefaultHandler DEFAULT_HANDLER = new DefaultHandler();
/**
* Holds the content handler.
*/
private ContentHandler _contentHandler;
/**
* Holds the error handler.
*/
private ErrorHandler _errorHandler;
/**
* Holds reusable StAX reader.
*/
private final XMLStreamReaderImpl _xmlReader = new XMLStreamReaderImpl();
/**
* Default constructor.
*/
public XMLReaderImpl() {
// Sets default handlers.
setContentHandler(DEFAULT_HANDLER);
setErrorHandler(DEFAULT_HANDLER);
}
/**
* Parses an XML document from the specified input stream
* (encoding retrieved from input source and the XML prolog if any).
*
* @param in the input stream with unknown encoding.
* @throws org.xml.sax.SAXException any SAX exception, possibly
* wrapping another exception.
* @throws IOException an IO exception from the parser,
* possibly from a byte stream or character stream
* supplied by the application.
*/
public void parse(InputStream in) throws IOException, SAXException {
try {
_xmlReader.setInput(in);
parseAll();
} catch (XMLStreamException e) {
if (e.getNestedException() instanceof IOException)
throw (IOException) e.getNestedException();
throw new SAXException(e.getMessage());
} finally {
_xmlReader.reset();
}
}
/**
* Parses an XML document from the specified input stream and encoding.
*
* @param in the input stream.
* @param encoding the input stream encoding.
* @throws org.xml.sax.SAXException any SAX exception, possibly
* wrapping another exception.
* @throws IOException an IO exception from the parser,
* possibly from a byte stream or character stream
* supplied by the application.
*/
public void parse(InputStream in, String encoding) throws IOException,
SAXException {
try {
_xmlReader.setInput(in, encoding);
parseAll();
} catch (XMLStreamException e) {
if (e.getNestedException() instanceof IOException)
throw (IOException) e.getNestedException();
throw new SAXException(e.getMessage());
} finally {
_xmlReader.reset();
}
}
/**
* Parses an XML document using the specified reader.
*
* @param reader the document reader.
* @throws SAXException any SAX exception, possibly wrapping another
* exception.
* @throws IOException an IO exception from the parser, possibly from
* a byte stream or character stream supplied by the application.
* @see javolution.io.UTF8StreamReader
* @see javolution.io.UTF8ByteBufferReader
* @see javolution.io.CharSequenceReader
*/
public void parse(Reader reader) throws IOException, SAXException {
try {
_xmlReader.setInput(reader);
parseAll();
} catch (XMLStreamException e) {
if (e.getNestedException() instanceof IOException)
throw (IOException) e.getNestedException();
throw new SAXException(e.getMessage());
} finally {
_xmlReader.reset();
}
}
// Implements XMLReader interface.
public void parse(InputSource input) throws IOException, SAXException {
Reader reader = input.getCharacterStream();
if (reader != null) {
parse(reader);
} else {
InputStream inStream = input.getByteStream();
if (inStream != null) {
parse(inStream, input.getEncoding());
} else {
parse(input.getSystemId());
}
}
}
// Implements XMLReader interface.
public void parse(String systemId) throws IOException, SAXException {
InputStream inStream;
try {
URL url = new URL(systemId);
inStream = url.openStream();
} catch (Exception urlException) { // Try as filename.
try {
inStream = new FileInputStream(systemId);
} catch (Exception fileException) {
throw new UnsupportedOperationException("Cannot parse "
+ systemId);
}
}
parse(inStream);
}
// Implements XMLReader interface.
public void setContentHandler(ContentHandler handler) {
if (handler != null) {
_contentHandler = handler;
} else {
throw new NullPointerException();
}
}
// Implements XMLReader interface.
public ContentHandler getContentHandler() {
return (_contentHandler == DEFAULT_HANDLER) ? null : _contentHandler;
}
// Implements XMLReader interface.
public void setErrorHandler(ErrorHandler handler) {
if (handler != null) {
_errorHandler = handler;
} else {
throw new NullPointerException();
}
}
// Implements XMLReader interface.
public ErrorHandler getErrorHandler() {
return (_errorHandler == DEFAULT_HANDLER) ? null : _errorHandler;
}
// Implements XMLReader interface.
public boolean getFeature(String name) throws SAXNotRecognizedException,
SAXNotSupportedException {
if (name.equals("http://xml.org/sax/features/namespaces")) {
return true;
} else if (name
.equals("http://xml.org/sax/features/namespace-prefixes")) {
return true;
} else {
throw new SAXNotRecognizedException("Feature " + name
+ " not recognized");
}
}
public void setFeature(String name, boolean value)
throws SAXNotRecognizedException, SAXNotSupportedException {
if (name.equals("http://xml.org/sax/features/namespaces")
|| name.equals("http://xml.org/sax/features/namespace-prefixes")) {
return; // Ignores, these features are always set.
} else {
throw new SAXNotRecognizedException("Feature " + name
+ " not recognized");
}
}
public Object getProperty(String name) throws SAXNotRecognizedException,
SAXNotSupportedException {
throw new SAXNotRecognizedException("Property " + name
+ " not recognized");
}
public void setProperty(String name, Object value)
throws SAXNotRecognizedException, SAXNotSupportedException {
throw new SAXNotRecognizedException("Property " + name
+ " not recognized");
}
public void setEntityResolver(EntityResolver resolver) {
_entityResolver = resolver;
}
private EntityResolver _entityResolver;
public EntityResolver getEntityResolver() {
return _entityResolver;
}
public void setDTDHandler(DTDHandler handler) {
_dtdHandler = handler;
}
private DTDHandler _dtdHandler;
public DTDHandler getDTDHandler() {
return _dtdHandler;
}
// Implements Reusable.
public void reset() {
setContentHandler(DEFAULT_HANDLER);
setErrorHandler(DEFAULT_HANDLER);
_xmlReader.reset();
}
/**
* Parses the whole document using the real-time pull parser.
*
* @throws SAXException any SAX exception, possibly wrapping another
* exception.
* @throws IOException an IO exception from the parser, possibly from
* a byte stream or character stream supplied by the application.
*/
private void parseAll() throws XMLStreamException, SAXException {
int eventType = _xmlReader.getEventType();
if (eventType != XMLStreamConstants.START_DOCUMENT)
throw new SAXException("Currently parsing");
_contentHandler.startDocument();
boolean doContinue = true;
while (doContinue) {
CharArray uri, localName, qName, prefix, text;
switch (_xmlReader.next()) {
case XMLStreamConstants.START_ELEMENT:
// Start prefix mapping.
for (int i = 0, count = _xmlReader.getNamespaceCount(); i < count; i++) {
prefix = _xmlReader.getNamespacePrefix(i);
prefix = (prefix == null) ? NO_CHAR : prefix; // Default namespace is ""
uri = _xmlReader.getNamespaceURI(i);
_contentHandler.startPrefixMapping(prefix, uri);
}
// Start element.
uri = _xmlReader.getNamespaceURI();
uri = (uri == null) ? NO_CHAR : uri;
localName = _xmlReader.getLocalName();
qName = _xmlReader.getQName();
_contentHandler.startElement(uri, localName, qName,
_xmlReader.getAttributes());
break;
case XMLStreamConstants.END_ELEMENT:
// End element.
uri = _xmlReader.getNamespaceURI();
uri = (uri == null) ? NO_CHAR : uri;
localName = _xmlReader.getLocalName();
qName = _xmlReader.getQName();
_contentHandler.endElement(uri, localName, qName);
// End prefix mapping.
for (int i = 0, count = _xmlReader.getNamespaceCount(); i < count; i++) {
prefix = _xmlReader.getNamespacePrefix(i);
prefix = (prefix == null) ? NO_CHAR : prefix; // Default namespace is ""
_contentHandler.endPrefixMapping(prefix);
}
break;
case XMLStreamConstants.CDATA:
case XMLStreamConstants.CHARACTERS:
text = _xmlReader.getText();
_contentHandler.characters(text.array(), text.offset(),
text.length());
break;
case XMLStreamConstants.SPACE:
text = _xmlReader.getText();
_contentHandler.ignorableWhitespace(text.array(),
text.offset(), text.length());
break;
case XMLStreamConstants.PROCESSING_INSTRUCTION:
_contentHandler.processingInstruction(
_xmlReader.getPITarget(), _xmlReader.getPIData());
break;
case XMLStreamConstants.COMMENT:
// Ignores.
break;
case XMLStreamConstants.END_DOCUMENT:
doContinue = false;
_xmlReader.close();
break;
}
}
}
private static final CharArray NO_CHAR = new CharArray("");
}