/* $Id: ContentHandlerToXMLStreamWriter.java,v 1.6 2005/10/25 18:36:24 ryan_shoemaker Exp $
*
* Copyright (c) 2004, Sun Microsystems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* * Neither the name of Sun Microsystems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package javanet.staxutils;
import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.util.Stack;
/**
* This is a simple utility class that adapts SAX events into StAX
* {@link javax.xml.stream.XMLStreamWriter} events, bridging between
* the two parser technologies.
*
* This ContentHandler does not own the XMLStreamWriter. Therefore, it will
* not close or flush the writer at any point.
*
* @author [email protected]
* @version 1.0
*/
public class ContentHandlerToXMLStreamWriter extends DefaultHandler {
// SAX events will be sent to this XMLStreamWriter
private final XMLStreamWriter staxWriter;
// storage for prefix bindings
private final Stack prefixBindings;
public ContentHandlerToXMLStreamWriter(XMLStreamWriter staxCore) {
this .staxWriter = staxCore;
prefixBindings = new Stack(); // default of 10 seems reasonable
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#endDocument()
*/
public void endDocument() throws SAXException {
try {
staxWriter.writeEndDocument();
staxWriter.flush();
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#startDocument()
*/
public void startDocument() throws SAXException {
try {
staxWriter.writeStartDocument();
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#characters(char[], int, int)
*/
public void characters(char[] ch, int start, int length)
throws SAXException {
try {
staxWriter.writeCharacters(ch, start, length);
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#ignorableWhitespace(char[], int, int)
*/
public void ignorableWhitespace(char[] ch, int start, int length)
throws SAXException {
characters(ch, start, length);
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#endPrefixMapping(java.lang.String)
*/
public void endPrefixMapping(String prefix) throws SAXException {
// TODO: no-op?
// I think we can ignore these SAX events because StAX
// automatically scopes the prefix bindings.
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#skippedEntity(java.lang.String)
*/
public void skippedEntity(String name) throws SAXException {
try {
staxWriter.writeEntityRef(name);
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#setDocumentLocator(org.xml.sax.Locator)
*/
public void setDocumentLocator(Locator locator) {
// TODO: no-op?
// there doesn't seem to be any way to pass location info
// along to the XMLStreamWriter. On the XMLEventWriter side, you
// can set the location info on the event objects.
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#processingInstruction(java.lang.String,
* java.lang.String)
*/
public void processingInstruction(String target, String data)
throws SAXException {
try {
staxWriter.writeProcessingInstruction(target, data);
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#startPrefixMapping(java.lang.String,
* java.lang.String)
*/
public void startPrefixMapping(String prefix, String uri)
throws SAXException {
if (prefix.equals("xml")) {
return;
}
// defend against parsers that pass null in for "xmlns" prefix
if (prefix == null) {
prefix = "";
}
prefixBindings.add(prefix);
prefixBindings.add(uri);
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#endElement(java.lang.String,
* java.lang.String, java.lang.String)
*/
public void endElement(String namespaceURI, String localName,
String qName) throws SAXException {
try {
// TODO: is this all we have to do?
staxWriter.writeEndElement();
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/*
* (non-Javadoc)
*
* @see org.xml.sax.ContentHandler#startElement(java.lang.String,
* java.lang.String, java.lang.String, org.xml.sax.Attributes)
*/
public void startElement(String namespaceURI, String localName,
String qName, Attributes atts) throws SAXException {
try {
staxWriter.writeStartElement(getPrefix(qName), localName,
namespaceURI);
String uri, prefix;
while (prefixBindings.size() != 0) {
uri = (String) prefixBindings.pop();
prefix = (String) prefixBindings.pop();
if (prefix.length() == 0) {
staxWriter.setDefaultNamespace(uri);
} else {
staxWriter.setPrefix(prefix, uri);
}
// this method handles "", null, and "xmlns" prefixes properly
staxWriter.writeNamespace(prefix, uri);
}
writeAttributes(atts);
} catch (XMLStreamException e) {
throw new SAXException(e);
}
}
/**
* Generate a StAX writeAttribute event for each attribute
*
* @param atts
* attributes from the SAX event
*/
private void writeAttributes(Attributes atts)
throws XMLStreamException {
for (int i = 0; i < atts.getLength(); i++) {
final String prefix = getPrefix(atts.getQName(i));
if (!prefix.equals("xmlns")) { // defend againts broken transformers that report xmlns decls as attrs
staxWriter.writeAttribute(prefix, atts.getURI(i), atts
.getLocalName(i), atts.getValue(i));
}
}
}
/**
* Pull the prefix off of the specified QName.
*
* @param qName
* the QName
* @return the prefix or the empty string if it doesn't exist.
*/
private String getPrefix(String qName) {
int idx = qName.indexOf(':');
if (idx == -1) {
return "";
} else {
return qName.substring(0, idx);
}
}
}
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