/*
* eXist Open Source Native XML Database
* Copyright (C) 2005-2009 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.util;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.exist.dom.DocumentImpl;
import org.exist.dom.NodeProxy;
import org.exist.memtree.SAXAdapter;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
import org.exist.storage.lock.Lock;
import org.exist.xmldb.XmldbURI;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.Sequence;
import org.exist.source.Source;
import org.exist.source.SourceFactory;
import org.exist.source.URLSource;
import org.exist.util.XMLReaderPool;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
/**
* Utilities for XPath doc related functions
*
* @author wolf
* @author Pierrick Brihaye <pierrick.brihaye@free.fr>
*/
//TODO : many more improvements to handle efficiently any URI
public class DocUtils {
public static Sequence getDocument(XQueryContext context, String path) throws XPathException, PermissionDeniedException {
return getDocumentByPath(context, path);
}
public static boolean isDocumentAvailable(XQueryContext context, String path) throws XPathException {
try {
Sequence seq = getDocumentByPath(context, path);
return (seq != null && seq.effectiveBooleanValue());
}
catch (PermissionDeniedException e) {
return false;
}
}
private static Sequence getDocumentByPath(XQueryContext context, String path) throws XPathException, PermissionDeniedException
{
Sequence document = Sequence.EMPTY_SEQUENCE;
if(path.matches("^[a-z]+:.*") && !path.startsWith("xmldb:"))
{
XMLReader reader = null;
/* URL */
try {
Source source = SourceFactory.getSource(context.getBroker(), "", path, false);
InputStream istream = source.getInputStream();
if (source instanceof URLSource) {
int responseCode = ((URLSource) source).getResponseCode();
if (responseCode == HttpURLConnection.HTTP_NOT_FOUND) {
// Special case: '404'
return Sequence.EMPTY_SEQUENCE;
} else if (responseCode != HttpURLConnection.HTTP_OK) {
throw new PermissionDeniedException("Server returned code " + responseCode);
}
}
//TODO : process pseudo-protocols URLs more efficiently.
org.exist.memtree.DocumentImpl memtreeDoc = null;
// we use eXist's in-memory DOM implementation
reader = context.getBroker().getBrokerPool().getParserPool().borrowXMLReader();
//TODO : we should be able to cope with context.getBaseURI()
InputSource src = new InputSource(istream);
SAXAdapter adapter = new SAXAdapter();
reader.setContentHandler(adapter);
reader.parse(src);
Document doc = adapter.getDocument();
memtreeDoc = (org.exist.memtree.DocumentImpl)doc;
memtreeDoc.setContext(context);
memtreeDoc.setDocumentURI(path);
document = memtreeDoc;
} catch(ConnectException e) {
// prevent long stacktraces
throw new XPathException(e.getMessage()+ " ("+path+")");
} catch(MalformedURLException e) {
throw new XPathException(e.getMessage(), e);
} catch(SAXException e) {
throw new XPathException(e.getMessage(), e);
}
catch(IOException e) {
// Special case: FileNotFoundException
if(e instanceof FileNotFoundException)
{
return Sequence.EMPTY_SEQUENCE;
}
else
{
throw new XPathException(e.getMessage(), e);
}
} finally {
if (reader != null)
context.getBroker().getBrokerPool().getParserPool().returnXMLReader(reader);
}
}
else
{
/* Database documents */
// check if the loaded documents should remain locked
boolean lockOnLoad = context.lockDocumentsOnLoad();
int lockType = lockOnLoad ? Lock.WRITE_LOCK : Lock.READ_LOCK;
DocumentImpl doc = null;
try
{
XmldbURI pathUri = XmldbURI.xmldbUriFor(path, false);
XmldbURI baseURI = context.getBaseURI().toXmldbURI();
if (!(baseURI.equals("") || baseURI.equals("/db"))) {
// relative collection Path: add the current base URI
pathUri = baseURI.resolveCollectionPath(pathUri);
}
// relative collection Path: add the current module call URI
try {
pathUri = XmldbURI.xmldbUriFor(context.getModuleLoadPath()).resolveCollectionPath(pathUri);
} catch (Exception e) {
//workaround: ignore Windows issue
}
// try to open the document and acquire a lock
doc = context.getBroker().getXMLResource(pathUri, lockType);
if(doc != null)
{
if(!doc.getPermissions().validate(context.getUser(), Permission.READ))
{
doc.getUpdateLock().release(lockType);
throw new PermissionDeniedException("Insufficient privileges to read resource " + path);
}
if(doc.getResourceType() == DocumentImpl.BINARY_FILE)
{
throw new XPathException("Document is a binary resource, not an XML document. Please consider using the function util:binary-doc() to retrieve a reference to it.");
}
if(lockOnLoad)
{
// add the document to the list of locked documents
context.addLockedDocument(doc);
}
document = new NodeProxy(doc);
}
}
catch(PermissionDeniedException e)
{
throw e;
}
catch(URISyntaxException e)
{
throw new XPathException(e);
}
finally
{
// release all locks unless lockOnLoad is true
if(!lockOnLoad && doc != null)
doc.getUpdateLock().release(lockType);
}
}
return document;
}
}