/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: SourceTreeManager.java 468655 2006-10-28 07:12:06Z minchau $
*/
package org.apache.xpath;
import java.io.IOException;
import java.util.Vector;
import javax.xml.transform.Source;
import javax.xml.transform.SourceLocator;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.stream.StreamSource;
import org.apache.xml.dtm.DTM;
import org.apache.xml.utils.SystemIDResolver;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLReaderFactory;
/**
* This class bottlenecks all management of source trees. The methods
* in this class should allow easy garbage collection of source
* trees (not yet!), and should centralize parsing for those source trees.
*/
public class SourceTreeManager
{
/** Vector of SourceTree objects that this manager manages. */
private Vector m_sourceTree = new Vector();
/**
* Reset the list of SourceTree objects that this manager manages.
*
*/
public void reset()
{
m_sourceTree = new Vector();
}
/** The TrAX URI resolver used to obtain source trees. */
URIResolver m_uriResolver;
/**
* Set an object that will be used to resolve URIs used in
* document(), etc.
* @param resolver An object that implements the URIResolver interface,
* or null.
*/
public void setURIResolver(URIResolver resolver)
{
m_uriResolver = resolver;
}
/**
* Get the object that will be used to resolve URIs used in
* document(), etc.
* @return An object that implements the URIResolver interface,
* or null.
*/
public URIResolver getURIResolver()
{
return m_uriResolver;
}
/**
* Given a document, find the URL associated with that document.
* @param owner Document that was previously processed by this liaison.
*
* @return The base URI of the owner argument.
*/
public String findURIFromDoc(int owner)
{
int n = m_sourceTree.size();
for (int i = 0; i < n; i++)
{
SourceTree sTree = (SourceTree) m_sourceTree.elementAt(i);
if (owner == sTree.m_root)
return sTree.m_url;
}
return null;
}
/**
* This will be called by the processor when it encounters
* an xsl:include, xsl:import, or document() function.
*
* @param base The base URI that should be used.
* @param urlString Value from an xsl:import or xsl:include's href attribute,
* or a URI specified in the document() function.
*
* @return a Source that can be used to process the resource.
*
* @throws IOException
* @throws TransformerException
*/
public Source resolveURI(
String base, String urlString, SourceLocator locator)
throws TransformerException, IOException
{
Source source = null;
if (null != m_uriResolver)
{
source = m_uriResolver.resolve(urlString, base);
}
if (null == source)
{
String uri = SystemIDResolver.getAbsoluteURI(urlString, base);
source = new StreamSource(uri);
}
return source;
}
/** JJK: Support <?xalan:doc_cache_off?> kluge in ElemForEach.
* TODO: This function is highly dangerous. Cache management must be improved.
*
* @param n The node to remove.
*/
public void removeDocumentFromCache(int n)
{
if(DTM.NULL ==n)
return;
for(int i=m_sourceTree.size()-1;i>=0;--i)
{
SourceTree st=(SourceTree)m_sourceTree.elementAt(i);
if(st!=null && st.m_root==n)
{
m_sourceTree.removeElementAt(i);
return;
}
}
}
/**
* Put the source tree root node in the document cache.
* TODO: This function needs to be a LOT more sophisticated.
*
* @param n The node to cache.
* @param source The Source object to cache.
*/
public void putDocumentInCache(int n, Source source)
{
int cachedNode = getNode(source);
if (DTM.NULL != cachedNode)
{
if (!(cachedNode == n))
throw new RuntimeException(
"Programmer's Error! "
+ "putDocumentInCache found reparse of doc: "
+ source.getSystemId());
return;
}
if (null != source.getSystemId())
{
m_sourceTree.addElement(new SourceTree(n, source.getSystemId()));
}
}
/**
* Given a Source object, find the node associated with it.
*
* @param source The Source object to act as the key.
*
* @return The node that is associated with the Source, or null if not found.
*/
public int getNode(Source source)
{
// if (source instanceof DOMSource)
// return ((DOMSource) source).getNode();
// TODO: Not sure if the BaseID is really the same thing as the ID.
String url = source.getSystemId();
if (null == url)
return DTM.NULL;
int n = m_sourceTree.size();
// System.out.println("getNode: "+n);
for (int i = 0; i < n; i++)
{
SourceTree sTree = (SourceTree) m_sourceTree.elementAt(i);
// System.out.println("getNode - url: "+url);
// System.out.println("getNode - sTree.m_url: "+sTree.m_url);
if (url.equals(sTree.m_url))
return sTree.m_root;
}
// System.out.println("getNode - returning: "+node);
return DTM.NULL;
}
/**
* Get the source tree from the a base URL and a URL string.
*
* @param base The base URI to use if the urlString is relative.
* @param urlString An absolute or relative URL string.
* @param locator The location of the caller, for diagnostic purposes.
*
* @return should be a non-null reference to the node identified by the
* base and urlString.
*
* @throws TransformerException If the URL can not resolve to a node.
*/
public int getSourceTree(
String base, String urlString, SourceLocator locator, XPathContext xctxt)
throws TransformerException
{
// System.out.println("getSourceTree");
try
{
Source source = this.resolveURI(base, urlString, locator);
// System.out.println("getSourceTree - base: "+base+", urlString: "+urlString+", source: "+source.getSystemId());
return getSourceTree(source, locator, xctxt);
}
catch (IOException ioe)
{
throw new TransformerException(ioe.getMessage(), locator, ioe);
}
/* catch (TransformerException te)
{
throw new TransformerException(te.getMessage(), locator, te);
}*/
}
/**
* Get the source tree from the input source.
*
* @param source The Source object that should identify the desired node.
* @param locator The location of the caller, for diagnostic purposes.
*
* @return non-null reference to a node.
*
* @throws TransformerException if the Source argument can't be resolved to
* a node.
*/
public int getSourceTree(Source source, SourceLocator locator, XPathContext xctxt)
throws TransformerException
{
int n = getNode(source);
if (DTM.NULL != n)
return n;
n = parseToNode(source, locator, xctxt);
if (DTM.NULL != n)
putDocumentInCache(n, source);
return n;
}
/**
* Try to create a DOM source tree from the input source.
*
* @param source The Source object that identifies the source node.
* @param locator The location of the caller, for diagnostic purposes.
*
* @return non-null reference to node identified by the source argument.
*
* @throws TransformerException if the source argument can not be resolved
* to a source node.
*/
public int parseToNode(Source source, SourceLocator locator, XPathContext xctxt)
throws TransformerException
{
try
{
Object xowner = xctxt.getOwnerObject();
DTM dtm;
if(null != xowner && xowner instanceof org.apache.xml.dtm.DTMWSFilter)
{
dtm = xctxt.getDTM(source, false,
(org.apache.xml.dtm.DTMWSFilter)xowner, false, true);
}
else
{
dtm = xctxt.getDTM(source, false, null, false, true);
}
return dtm.getDocument();
}
catch (Exception e)
{
//e.printStackTrace();
throw new TransformerException(e.getMessage(), locator, e);
}
}
/**
* This method returns the SAX2 parser to use with the InputSource
* obtained from this URI.
* It may return null if any SAX2-conformant XML parser can be used,
* or if getInputSource() will also return null. The parser must
* be free for use (i.e.
* not currently in use for another parse().
*
* @param inputSource The value returned from the URIResolver.
* @return a SAX2 XMLReader to use to resolve the inputSource argument.
* @param locator The location of the original caller, for diagnostic purposes.
*
* @throws TransformerException if the reader can not be created.
*/
public static XMLReader getXMLReader(Source inputSource, SourceLocator locator)
throws TransformerException
{
try
{
XMLReader reader = (inputSource instanceof SAXSource)
? ((SAXSource) inputSource).getXMLReader() : null;
if (null == reader)
{
try {
javax.xml.parsers.SAXParserFactory factory=
javax.xml.parsers.SAXParserFactory.newInstance();
factory.setNamespaceAware( true );
javax.xml.parsers.SAXParser jaxpParser=
factory.newSAXParser();
reader=jaxpParser.getXMLReader();
} catch( javax.xml.parsers.ParserConfigurationException ex ) {
throw new org.xml.sax.SAXException( ex );
} catch( javax.xml.parsers.FactoryConfigurationError ex1 ) {
throw new org.xml.sax.SAXException( ex1.toString() );
} catch( NoSuchMethodError ex2 ) {
}
catch (AbstractMethodError ame){}
if(null == reader)
reader = XMLReaderFactory.createXMLReader();
}
try
{
reader.setFeature("http://xml.org/sax/features/namespace-prefixes",
true);
}
catch (org.xml.sax.SAXException se)
{
// What can we do?
// TODO: User diagnostics.
}
return reader;
}
catch (org.xml.sax.SAXException se)
{
throw new TransformerException(se.getMessage(), locator, se);
}
}
}