/*
* 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.entityhublinking;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.clerezza.rdf.core.Resource;
import org.apache.clerezza.rdf.core.UriRef;
import org.apache.clerezza.rdf.core.impl.PlainLiteralImpl;
import org.apache.stanbol.enhancer.engines.entitylinking.Entity;
import org.apache.stanbol.enhancer.engines.entitylinking.EntitySearcher;
import org.apache.stanbol.enhancer.engines.entitylinking.EntitySearcherException;
import org.apache.stanbol.entityhub.servicesapi.Entityhub;
import org.apache.stanbol.entityhub.servicesapi.EntityhubException;
import org.apache.stanbol.entityhub.servicesapi.model.Representation;
import org.apache.stanbol.entityhub.servicesapi.model.rdf.RdfResourceEnum;
import org.apache.stanbol.entityhub.servicesapi.query.FieldQuery;
import org.apache.stanbol.entityhub.servicesapi.query.QueryResultList;
import org.osgi.framework.BundleContext;
import org.osgi.util.tracker.ServiceTrackerCustomizer;
public final class EntityhubSearcher extends TrackingEntitySearcher<Entityhub> implements EntitySearcher {
private final Integer limit;
private Map<UriRef,Collection<Resource>> originInfo;
public EntityhubSearcher(BundleContext context, Integer limit) {
this(context,limit,null);
}
public EntityhubSearcher(BundleContext context, Integer limit,ServiceTrackerCustomizer customizer) {
super(context,Entityhub.class,null,customizer);
this.limit = limit != null && limit > 0 ? limit : null;
this.originInfo = Collections.singletonMap(
new UriRef(RdfResourceEnum.site.getUri()),
(Collection<Resource>)Collections.singleton(
(Resource)new PlainLiteralImpl("entityhub")));
}
@Override
public Entity get(UriRef id,Set<UriRef> includeFields) throws EntitySearcherException {
if(id == null || id.getUnicodeString().isEmpty()){
return null;
}
Entityhub entityhub = getSearchService();
if(entityhub == null){
throw new EntitySearcherException("The Entityhub is currently not active");
}
org.apache.stanbol.entityhub.servicesapi.model.Entity entity;
try {
entity = entityhub.getEntity(id.getUnicodeString());
} catch (EntityhubException e) {
throw new EntitySearcherException("Exception while getting "+id+
" from the Entityhub",e);
}
return entity == null ? null : new EntityhubEntity(entity.getRepresentation());
}
@Override
public Collection<? extends Entity> lookup(UriRef field,
Set<UriRef> includeFields,
List<String> search,
String[] languages,
Integer limit) throws EntitySearcherException {
Entityhub entityhub = getSearchService();
if(entityhub == null){
throw new EntitySearcherException("The Entityhub is currently not active");
}
FieldQuery query = EntitySearcherUtils.createFieldQuery(entityhub.getQueryFactory(),
field, includeFields, search, languages);
if(limit != null && limit > 0){
query.setLimit(limit);
} else if(this.limit != null){
query.setLimit(this.limit);
}
QueryResultList<Representation> results;
try {
results = entityhub.find(query);
} catch (EntityhubException e) {
throw new EntitySearcherException("Exception while searchign for "+
search+'@'+Arrays.toString(languages)+"in the Entityhub", e);
}
Collection<Entity> entities = new ArrayList<Entity>(results.size());
for(Representation result : results){
entities.add(new EntityhubEntity(result));
}
return entities;
}
@Override
public boolean supportsOfflineMode() {
return true; //the entityhub is always offline
}
@Override
public Integer getLimit() {
return limit;
}
@Override
public Map<UriRef,Collection<Resource>> getOriginInformation() {
return originInfo;
}
}