Xalan: The javax.xml.transform.sax.TemplatesHandler Class

Extends: org.xml.sax.ContentHandler

Members

Members inherited from org.xml.sax.ContentHandler

Overview

This class is a SAX ContentHandler that may be used to process SAX parse events (parsing transformation instructions) into a Templates object. This is the alternate way of getting compiled stylesheets. In my other transformation related tutorial, I have used the raw stylesheet( passed uri of stylesheet to the transform() method to perform transformation). This class provided alternate way of parsing the stylesheet and converting the stylesheet into Templates object.

This is class provides mechanism of how to get Templates object. So user can control any error that might occur during parsing mechanism. If any error occurs no further processing can be done so utilization of resources can be utilized properly.

Method Overviews

I will covering here, how to get Templates object from a stylesheet. When a TemplatesHandler object is used as a ContentHandler for the parsing of transformation instructions, it creates a Templates object, which the caller can get once the SAX events have been completed.

Example of getTemplates():

getTemplates()  is used to get javax.xml.transform.Templates object.

try{

            TransformerFactory tFactory = TransformerFactory.newInstance();

            // Determine whether the TransformerFactory supports The use of SAXSource

            // and SAXResult

            if (tFactory.getFeature(SAXSource.FEATURE) &&

                tFactory.getFeature(SAXResult.FEATURE)) {

                // Cast the TransformerFactory.

                SAXTransformerFactory saxTFactory = ((SAXTransformerFactory)

                        tFactory);

                // Create a ContentHandler to handle parsing of the stylesheet.

                TemplatesHandler templatesHandler = saxTFactory.

                        newTemplatesHandler();

               // TemplatesHandlerImpl tImpl = (TemplatesHandlerImpl)templatesHandler;

                // Create an XMLReader and set its ContentHandler.

                XMLReader reader = XMLReaderFactory.createXMLReader();

                reader.setContentHandler(templatesHandler);

                // Parse the stylesheet.                       

                reader.parse(stylesheetURI);

                //Get the Templates object from the ContentHandler.

                Templates templates = templatesHandler.getTemplates();

                // Create a ContentHandler to handle parsing of the XML source.

                TransformerHandler handler

                        = saxTFactory.newTransformerHandler(templates);

                // Reset the XMLReader's ContentHandler.

                reader.setContentHandler(handler);

                // Set the ContentHandler to also function as a LexicalHandler, which

                // includes "lexical" events (e.g., comments and CDATA).

                reader.setProperty(

                        "http://xml.org/sax/properties/lexical-handler",

                        handler);

                FileOutputStream fos = new FileOutputStream(outURI);

                //SerializerFactory.getSerializerFactory().;

                java.util.Properties prop = OutputPropertiesFactory.getDefaultMethodProperties("xml");

                Serializer serializer = SerializerFactory.getSerializer(prop);

                serializer.setOutputFormat(prop);

                // Set the result handling to be a serialization to the file output stream.

                Result result = new SAXResult(serializer.asContentHandler());

                handler.setResult(result);

                // Parse the XML input document.

                InputSource src = new InputSource(xmlfileURI);

                reader.parse(src);

            }

        }catch(Exception e){

            e.printStackTrace();

        }.

Example of getSystemId():

getSystemId()  is used to get the base ID (URI or system ID) from where relative URLs will be resolved.

templatesHandler.getSystemId();