/*
* 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.
*/
package org.apache.stanbol.enhancer.engines.xmpextractor;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.Map;
import org.apache.clerezza.rdf.core.Graph;
import org.apache.clerezza.rdf.core.MGraph;
import org.apache.clerezza.rdf.core.UriRef;
import org.apache.clerezza.rdf.core.impl.SimpleMGraph;
import org.apache.clerezza.rdf.core.serializedform.Parser;
import org.apache.clerezza.rdf.utils.GraphNode;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.apache.stanbol.commons.indexedgraph.IndexedMGraph;
import org.apache.stanbol.enhancer.servicesapi.ContentItem;
import org.apache.stanbol.enhancer.servicesapi.EngineException;
import org.apache.stanbol.enhancer.servicesapi.EnhancementEngine;
import org.apache.stanbol.enhancer.servicesapi.ServiceProperties;
import org.apache.stanbol.enhancer.servicesapi.impl.AbstractEnhancementEngine;
import org.apache.tika.parser.image.xmp.XMPPacketScanner;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@Component(immediate = true, metatype = true, inherit = true)
@Service
@org.apache.felix.scr.annotations.Properties(value={
@Property(name=EnhancementEngine.PROPERTY_NAME, value="xmpextractor")
})
public class XmpExtractorEngine extends AbstractEnhancementEngine<IOException,RuntimeException>
implements EnhancementEngine, ServiceProperties {
private static final Logger LOG = LoggerFactory.getLogger(XmpExtractorEngine.class);
@Reference
Parser parser;
/**
* The default value for the Execution of this Engine. Currently set to
* {@link ServiceProperties#ORDERING_PRE_PROCESSING}
*/
public static final Integer defaultOrder = ORDERING_PRE_PROCESSING;
@Override
public Map<String,Object> getServiceProperties() {
return Collections.unmodifiableMap(Collections.singletonMap(ENHANCEMENT_ENGINE_ORDERING, (Object) defaultOrder));
}
@Override
public int canEnhance(ContentItem ci) throws EngineException {
LOG.info("MimeType: {}", ci.getMimeType());
if (isSupported(ci.getMimeType())) {
return ENHANCE_ASYNC;
}
return CANNOT_ENHANCE;
}
@Override
public void computeEnhancements(ContentItem ci) throws EngineException {
InputStream in = ci.getBlob().getStream();
XMPPacketScanner scanner = new XMPPacketScanner();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
scanner.parse(in, baos);
} catch (IOException e) {
throw new EngineException(e);
}
byte[] bytes = baos.toByteArray();
if (bytes.length > 0) {
MGraph model = new IndexedMGraph();
parser.parse(model, new ByteArrayInputStream(bytes), "application/rdf+xml");
GraphNode gn = new GraphNode(
new UriRef("http://relative-uri.fake/"), model);
gn.replaceWith(ci.getUri());
ci.getLock().writeLock().lock();
try {
LOG.info("Model: {}",model);
ci.getMetadata().addAll(model);
} finally {
ci.getLock().writeLock().unlock();
}
}
}
private boolean isSupported(String mimeType) {
if (mimeType.startsWith("text/")) {
return false; //assuming text types cannot contain XMP
} else {
return true; // As there isn't a list of media types that can contain XMP
}
}
}