zongaro 2003/02/04 08:21:25
Modified: java/samples/CompiledServlet Tag: XSLTC_DTM README.servlet
Log:
Revised documentation to drop references to XSLTC Native API.
Revision Changes Path
No revision
No revision
1.2.12.1 +1 -144 xml-xalan/java/samples/CompiledServlet/README.servlet
Index: README.servlet
===================================================================
RCS file: /home/cvs/xml-xalan/java/samples/CompiledServlet/README.servlet,v
retrieving revision 1.2
retrieving revision 1.2.12.1
diff -u -r1.2 -r1.2.12.1
--- README.servlet 19 Jul 2001 12:49:46 -0000 1.2
+++ README.servlet 4 Feb 2003 16:21:25 -0000 1.2.12.1
@@ -3,7 +3,6 @@
o) HOW TO PROVIDE XSL TRANSFORMATIONS AS A WEB SERVICE
o) HOW TO INVOKE TRANSLETS FROM A SERVLET
- o) BUILDING YOUR OWN DOM CACHE
-----------------------------------------------------------------------
HOW TO PROVIDE XSL TRANSFORMATIONS AS A WEB SERVICE
@@ -22,149 +21,7 @@
TransformServlet.java
This file contains a minimal implementation of an XSL transformation
-servlet. It utilizes a cache to store the DOM trees for frequently
-accessed XML documents. These are not W3C DOM objects; They are
-specialized DOMs, native to XSLTC and optimzed for use with compiled
-translets. In addition to the initial input XML documents, the cache
-may contain DOMs for other XML input documents the translet requires
-at runtime, when the xsl:document() function is used in the stylesheet.
-
-Here's the essential code in the servlet for doing the transformation:
-
- // Get a reference to the translet class
- Class cls = Class.forName(transletName);
-
- // Instanciate a translet object (inherits AbstractTranslet)
- AbstractTranslet translet = (AbstractTranslet)cls.newInstance();
-
- // The translet needs a reference to the cache in case
- // in needs to load additional XML documents.
- translet.setDOMCache(cache);
-
- // Get the DOM from the DOM cache if current, otherwise
- // build and cache the DOM first
- DOMImpl dom = cache.retrieveDocument(documentURI, 0, translet);
-
- // Create output handler (you can plug in your own)
- DefaultSAXOutputHandler saxHandler;
- saxHandler = new DefaultSAXOutputHandler(out);
-
- // Start the transformation
- translet.transform(dom, new TextOutput(saxHandler));
-
------------------------------------------------------------------------
-BUILDING YOUR OWN DOM CACHE
-
-The interface for the DOM cache consists of a single method,
-and its definition can be found in:
-
- org/apache/xalan/xsltc/DOMCache.java
-
-The method contained in the interface is:
-
- public DOMImpl retrieveDocument(String uri,
- int mask,
- Translet translet);
-
-The responsibilities of this method are:
-
- A) Build new a DOMImpl and DTDMonitor for XML documents
- that are not already in the cache:
-
- // Instanciate a DOMImpl object
- Parser parser = new Parser();
- DOMImpl dom = new DOMImpl();
- // Set URI for imports, includes, and document() functions
- dom.setDocumentURI(uri);
- parser = factory.newSAXParser();
- reader = parser.getXMLReader();
- reader.setContentHandler(dom.getBuilder());
-
- // Use a DTDMonitor to track ID references in DTD
- DTDMonitor dtdMonitor = new DTDMonitor();
- dtdMonitor.handleDTD(reader);
-
- // Parse the input document and build DOM
- reader.parse(uri);
-
- At this point the DOMImpl and DTDMonitor objects are
- populated with the necessary data. The two objects
- are ready to be put in the cache (using the URI as
- the lookup key).
-
- B) For each time a new document is requested by a translet:
-
- // Expand translet's index array to fit this DOM
- translet.setIndexSize(dom.getSize());
-
- // Build indices for this DOM's DTD's ID references
- dtdMonitor.buildIdIndex(dom, mask, translet);
-
- // Pass unparsed entity URIs to the translet
- translet.setUnparsedEntityURIs(dtd.getUnparsedEntityURIs());
-
-Step A) must be done every time a document is read into the
-cache, and step B) every time a document is given to a
-translet.
-
-The XSLTC package contains an example implementation of a
-DOM cache, based on a very simple round-robin caching
-algorithm:
-
- org/apache/xalan/xsltc/dom/DocumentCache.java
+servlet.
-----------------------------------------------------------------------
-DOING TRANSFORMATIONS WITHOUT A DOM CACHE
-
-Alternatively, you can program a servlet to perform the same basic
-steps as the XSLTC command-line tool
-
- org.apache.xalan.xsltc.cmdline.Transform
-
-as follows:
-
-
- // Obtain a reference to the translet class
- Class cls = Class.forName(transletName);
- // Instanciate a translet object (inherits AbstractTranslet)
- AbstractTranslet translet = (AbstractTranslet)cls.newInstance();
-
- // Prepare the internal DOM tree
- final DOMImpl dom = new DOMImpl();
- dom.setDocumentURI(inputURI);
-
- // Create a parser for the input document
- // org.apache.xalan.xsltc.runtime.Constants sets NAMESPACE_FEATURE
- final SAXParserFactory facory = SAXFactory.newInstance();
- try {
- factory.setFeature(NAMESPACE_FEATURE,true);
- }
- catch (Exception e) {
- factory.setNamespaceAware(true);
- }
- parser = factory.newSAXParser();
- reader = parser.getXMLReader();
- reader.setContentHandler(dom.getBuilder());
-
- // Create a DTDMonitor for handling ID references in the DTD
- DTDMonitor dtdMonitor = new DTDMonitor();
- dtdMonitor.handleDTD(reader);
-
- // Create output handler (you can plug in your own)
- DefaultSAXOutputHandler saxHandler;
- saxHandler = new DefaultSAXOutputHandler(out);
-
- // Parse the document and build the internal DOM
- reader.parse(inputURI);
-
- // Pass information on id/key indicies to the translet
- translet.setIndexSize(dom.getSize());
- dtdMonitor.buildIdIndex(dom, 0, translet);
- translet.setUnparsedEntityURIs(dtdMonitor.getUnparsedEntityURIs());
-
- // Start the transformation
- translet.transform(dom, new TextOutput(saxHandler));
-
-
-------------------------------------------------------------
END OF README
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