/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2016 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.exist.xquery.functions.transform;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.exist.dom.persistent.BinaryDocument;
import org.exist.dom.persistent.DocumentImpl;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
import org.exist.storage.DBBroker;
import org.exist.xmldb.XmldbURI;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamSource;
import java.io.IOException;
import java.lang.reflect.Array;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Path;
/**
* Implementation of URIResolver which
* will resolve paths from the eXist database
*/
public class EXistURIResolver implements URIResolver {
private static final Logger LOG = LogManager.getLogger(EXistURIResolver.class);
final DBBroker broker;
final String basePath;
public EXistURIResolver(final DBBroker broker, final String docPath) {
this.broker = broker;
this.basePath = docPath;
LOG.debug("EXistURIResolver base path set to " + basePath);
}
/**
* Simplify a path removing any "." and ".." path elements.
* Assumes an absolute path is given.
*/
private String normalizePath(final String path) {
if (!path.startsWith("/")) {
throw new IllegalArgumentException("normalizePath may only be applied to an absolute path; " +
"argument was: " + path + "; base: " + basePath);
}
final String[] pathComponents = path.substring(1).split("/");
final int numPathComponents = Array.getLength(pathComponents);
final String[] simplifiedComponents = new String[numPathComponents];
int numSimplifiedComponents = 0;
for(final String s : pathComponents) {
if (s.length() == 0) {continue;} // Remove empty elements ("//")
if (".".equals(s)) {continue;} // Remove identity elements ("/./")
if ("..".equals(s)) { // Remove parent elements ("/../") unless at the root
if (numSimplifiedComponents > 0) {numSimplifiedComponents--;}
continue;
}
simplifiedComponents[numSimplifiedComponents++] = s;
}
if (numSimplifiedComponents == 0) {
return "/";
}
final StringBuilder b = new StringBuilder(path.length());
for(int x = 0; x < numSimplifiedComponents; x++) {
b.append("/").append(simplifiedComponents[x]);
}
if (path.endsWith("/")) {
b.append("/");
}
return b.toString();
}
@Override
public Source resolve(final String href, String base) throws TransformerException {
String path;
if (href.isEmpty()) {
path = base;
} else {
URI hrefURI = null;
try {
hrefURI = new URI(href);
} catch (final URISyntaxException e) {
}
if (hrefURI != null && hrefURI.isAbsolute()) {
path = href;
} else {
if (href.startsWith("/")) {
path = href;
} else if (href.startsWith(XmldbURI.EMBEDDED_SERVER_URI_PREFIX)) {
path = href.substring(XmldbURI.EMBEDDED_SERVER_URI_PREFIX.length());
} else if (base == null || base.length() == 0) {
path = basePath + "/" + href;
} else {
// Maybe base never contains this prefix? Check to be sure.
if (base.startsWith(XmldbURI.EMBEDDED_SERVER_URI_PREFIX)) {
base = base.substring(XmldbURI.EMBEDDED_SERVER_URI_PREFIX.length());
}
path = base.substring(0, base.lastIndexOf("/") + 1) + href;
}
}
}
LOG.debug("Resolving path " + href + " with base " + base + " to " + path);// + " (URI = " + uri.toASCIIString() + ")");
if (path.startsWith("/")) {
path = normalizePath(path);
return databaseSource(path);
} else {
return urlSource(path);
}
}
private Source urlSource(final String path) throws TransformerException {
try {
final URL url = new URL(path);
return new StreamSource(url.openStream());
} catch (final IOException e) {
throw new TransformerException(e.getMessage(), e);
}
}
private Source databaseSource(final String path) throws TransformerException {
final XmldbURI uri = XmldbURI.create(path);
final DocumentImpl doc;
try {
doc = broker.getResource(uri, Permission.READ);
if (doc == null) {
LOG.error("Document " + path + " not found");
throw new TransformerException("Resource " + path + " not found in database.");
}
final Source source;
if (doc instanceof BinaryDocument) {
final Path p = broker.getBinaryFile((BinaryDocument) doc);
source = new StreamSource(p.toFile());
source.setSystemId(p.toUri().toString());
return source;
} else {
source = new DOMSource(doc);
source.setSystemId(uri.toASCIIString());
return source;
}
} catch (final PermissionDeniedException | IOException e) {
throw new TransformerException(e.getMessage(), e);
}
}
}