/*******************************************************************************
* Copyright 2017 Graz University of Technology
* EAAF-Core Components has been developed in a cooperation between EGIZ,
* A-SIT Plus, A-SIT, and Graz University of Technology.
*
* Licensed under the EUPL, Version 1.2 or - as soon they will be approved by
* the European Commission - subsequent versions of the EUPL (the "Licence");
* You may not use this work except in compliance with the Licence.
* You may obtain a copy of the Licence at:
* https://joinup.ec.europa.eu/news/understanding-eupl-v12
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the Licence is distributed on an "AS IS" basis,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the Licence for the specific language governing permissions and
* limitations under the Licence.
*
* This product combines work with different licenses. See the "NOTICE" text
* file for details on the various modules and licenses.
* The "NOTICE" text file is part of the distribution. Any derivative works
* that you distribute must include a readable copy of the "NOTICE" text file.
*******************************************************************************/
/*******************************************************************************
*******************************************************************************/
/*******************************************************************************
*******************************************************************************/
package at.gv.egiz.eaaf.core.impl.utils;
import java.io.InputStream;
import org.apache.xerces.util.URI;
import org.apache.xerces.util.URI.MalformedURIException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import at.gv.egiz.eaaf.core.api.data.XMLNamespaceConstants;
/**
* An EntityResolver
that looks up entities stored as
* local resources.
*
*
The following DTDs are mapped to local resources: *
For all other resources, an attempt is made to resolve them as resources,
* either absolute or relative to Constants.SCHEMA_ROOT
.
*
*/
public class EAAFDomEntityResolver implements EntityResolver {
private static final Logger log = LoggerFactory.getLogger(EAAFDomEntityResolver.class);
/**
* Resolve an entity.
*
* The systemId
parameter is used to perform the lookup of the
* entity as a resource, either by interpreting the systemId
as
* an absolute resource path, or by appending the last path component of
* systemId
to Constants.SCHEMA_ROOT
.
*
* @param publicId The public ID of the resource.
* @param systemId The system ID of the resource.
* @return An InputSource
from which the entity can be read, or
* null
, if the entity could not be found.
* @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)
*/
public InputSource resolveEntity(String publicId, String systemId) {
InputStream stream;
int slashPos;
if (publicId != null) {
// check if we can resolve some standard dtd's
if (publicId.equalsIgnoreCase("-//W3C//DTD XMLSchema 200102//EN")) {
return new InputSource(
getClass().getResourceAsStream(
XMLNamespaceConstants.SCHEMA_ROOT + "XMLSchema.dtd"));
} else if (publicId.equalsIgnoreCase("datatypes")) {
return new InputSource(
getClass().getResourceAsStream(
XMLNamespaceConstants.SCHEMA_ROOT + "datatypes.dtd"));
}
} else if (systemId != null) {
// get the URI path
try {
URI uri = new URI(systemId);
systemId = uri.getPath();
if (!"file".equals(uri.getScheme()) || "".equals(systemId.trim())) {
return null;
}
} catch (MalformedURIException e) {
return null;
}
// try to get the resource from the full path
stream = getClass().getResourceAsStream(systemId);
if (stream != null) {
InputSource source = new InputSource(stream);
source.setSystemId(systemId);
return source;
}
// try to get the resource from the last path component
slashPos = systemId.lastIndexOf('/');
if (slashPos >= 0 && systemId.length() > slashPos) {
systemId = systemId.substring(slashPos + 1, systemId.length());
stream =
getClass().getResourceAsStream(XMLNamespaceConstants.SCHEMA_ROOT + systemId);
if (stream != null) {
InputSource source = new InputSource(stream);
source.setSystemId(systemId);
return source;
}
}
}
return null; // nothing found - let the parser handle the entity
}
}