I suggest StAX instead of SAX for this kind of transformation. It provides both reader and writer API's so can be used for both parsing and generation/serialization.
---------------------------------------- David A. Lee d...@calldei.com http://www.xmlsh.org -----Original Message----- From: Dawid Chodura [mailto:dawid.chod...@gmail.com] Sent: Tuesday, November 23, 2010 6:12 AM To: j-users@xerces.apache.org Subject: Transforming the stream of SAX events Hello, I want to transform an XML document, but I can't use XSLT, because I need to invoke Java code inside the transformation. If I understand correctly, Xalan is not an option. I don't need to keep the whole XML document in the memory for the transformation, so I decided to use SAX parser instead of DOM. I need to create new elements in the transformation. I read the sample xerces-2_10_0/samples/sax/Writer.java and it generates the output document manually: public void startElement(String uri, String local, String raw, Attributes attrs) throws SAXException { //... fOut.print('<'); fOut.print(raw); //... fOut.print('>'); fOut.flush(); } I don't want to generate the output manually. I wrote my own example, which uses org.cyberneko.html.parsers.SAXParser from NekoHTML parser: package saxtransformexample; import org.apache.xerces.util.AugmentationsImpl; import org.apache.xerces.util.XMLAttributesImpl; import org.apache.xerces.xni.Augmentations; import org.apache.xerces.xni.QName; import org.apache.xerces.xni.XMLAttributes; import org.apache.xerces.xni.XNIException; import org.apache.xerces.xni.parser.XMLDocumentFilter; import org.cyberneko.html.filters.DefaultFilter; import org.cyberneko.html.parsers.SAXParser; import org.xml.sax.InputSource; import javax.xml.transform.OutputKeys; import javax.xml.transform.Transformer; import javax.xml.transform.sax.SAXSource; import javax.xml.transform.sax.SAXTransformerFactory; import javax.xml.transform.stream.StreamResult; import java.io.StringReader; import java.io.StringWriter; public class SAXTransformExample { public static void main(String args[]) throws Exception { String inputString = "<div></div>"; StringWriter out = new StringWriter(); StreamResult result = new StreamResult(out); SAXTransformerFactory transformerFactory = (SAXTransformerFactory) SAXTransformerFactory.newInstance(); Transformer transformer = transformerFactory.newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "no"); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); transformer.setOutputProperty(OutputKeys.METHOD, "html"); XMLDocumentFilter[] filters = {new DefaultFilter() { @Override public void startElement(QName element, XMLAttributes attributes, Augmentations augs) throws XNIException { if (!element.localpart.toLowerCase().equals("div")) { super.startElement(element, attributes, augs); } else { super.startElement(element, attributes, augs); super.startElement(new QName("", "p", "p", null), new XMLAttributesImpl(), new AugmentationsImpl()); } } @Override public void endElement(QName element, Augmentations augs) throws XNIException { if (!element.localpart.toLowerCase().equals("div")) { super.endElement(element, augs); } else { super.endElement(new QName("", "p", "p", null), new AugmentationsImpl()); super.endElement(element, augs); } } }}; SAXParser parser = new SAXParser(); parser.setFeature("http://xml.org/sax/features/namespaces";, false); parser.setFeature("http://cyberneko.org/html/features/balance-tags/document- fragment", true); parser.setProperty("http://cyberneko.org/html/properties/filters";, filters); parser.setProperty("http://cyberneko.org/html/properties/names/elems";, "lower"); transformer.transform(new SAXSource(parser, new InputSource(new StringReader(inputString))), result); System.out.println("RESULT:" + out.getBuffer().toString() + ":"); } } It prints out: RESULT:<div><p></p></div> The problem is that it uses XNI and since I'm not writing a parser I think I shouldn't use XNI at all. There is an example: http://book.javanb.com/xml-and-java-developing-web-applications-2nd/02017700 40_ch05lev1sec2.html OutputFormat format = new OutputFormat("xml", "UTF-8", false); format.setPreserveSpace(true); ContentHandler handler = new XMLSerializer(System.out, format); XMLReader parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser"); XMLReader filter = new MailFilter(parser); filter.setContentHandler(handler); filter.parse(argv[0]); MailFilter extends org.xml.sax.helpers.XMLFilterImpl. The example uses org.apache.xml.serialize.XMLSerializer, which is deprecated in Xerces 2.9.0 API: Deprecated. This class was deprecated in Xerces 2.9.0. It is recommended that new applications use the DOM Level 3 LSSerializer or JAXP's Transformation API for XML (TrAX) for serializing XML. See the Xerces documentation for more information. http://xerces.apache.org/xerces2-j/javadocs/other/org/apache/xml/serialize/X MLSerializer.html If I don't want to use DOM, I assume I can't use DOM Level 3 LSSerializer. If I don't want to use XSLT, I assume I can't use JAXP's Transformation API for XML (TrAX) for serializing XML. What is the proper way to transform the stream of SAX events into another stream of SAX events, so that I don't need to write my own parser or my own serializer? Best regards, Dawid Chodura --------------------------------------------------------------------- To unsubscribe, e-mail: j-users-unsubscr...@xerces.apache.org For additional commands, e-mail: j-users-h...@xerces.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: j-users-unsubscr...@xerces.apache.org For additional commands, e-mail: j-users-h...@xerces.apache.org
