/*
* Hibernate OGM, Domain model persistence for NoSQL datastores
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.ogm.datastore.neo4j.query.parsing.impl;
import java.util.Map;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.engine.query.spi.ParameterMetadata;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.hql.QueryParser;
import org.hibernate.hql.ast.spi.EntityNamesResolver;
import org.hibernate.ogm.OgmSession;
import org.hibernate.ogm.query.NoSQLQuery;
import org.hibernate.ogm.query.impl.NoSQLQueryImpl;
import org.hibernate.ogm.service.impl.BaseQueryParserService;
import org.hibernate.ogm.service.impl.SessionFactoryEntityNamesResolver;
import org.hibernate.ogm.util.impl.Log;
import org.hibernate.ogm.util.impl.LoggerFactory;
/**
* @author Davide D'Alto <davide@hibernate.org>
*/
public class Neo4jBasedQueryParserService extends BaseQueryParserService {
private static final Log log = LoggerFactory.make();
private volatile SessionFactoryEntityNamesResolver entityNamesResolver;
@Override
public Query getParsedQueryExecutor(OgmSession session, String queryString, Map<String, Object> namedParameters) {
QueryParser queryParser = new QueryParser();
Neo4jProcessingChain processingChain = createProcessingChain( session, unwrap( namedParameters ) );
Neo4jQueryParsingResult result = queryParser.parseQuery( queryString, processingChain );
log.createdQuery( queryString, result );
NoSQLQuery query = nosqlQuery( session, result );
return query;
}
private NoSQLQuery nosqlQuery(OgmSession session, Neo4jQueryParsingResult result) {
NoSQLQuery query = new NoSQLQueryImpl( result.getQuery(), (SessionImplementor) session, new ParameterMetadata( null, null ) );
// Register the result types of the query; Currently either a number of scalar values or an entity return
// are supported only; JP-QL would actually a combination of both, though (see OGM-514)
if ( hasProjections( result ) ) {
for ( String field : result.getProjections() ) {
query.addScalar( field );
}
}
else {
query.addEntity( result.getEntityType() );
}
return query;
}
private boolean hasProjections(Neo4jQueryParsingResult result) {
return result.getProjections() != null && !result.getProjections().isEmpty();
}
private Neo4jProcessingChain createProcessingChain(Session session, Map<String, Object> namedParameters) {
EntityNamesResolver entityNamesResolver = getDefinedEntityNames( session.getSessionFactory() );
return new Neo4jProcessingChain( (SessionFactoryImplementor) session.getSessionFactory(), entityNamesResolver, namedParameters );
}
private EntityNamesResolver getDefinedEntityNames(SessionFactory sessionFactory) {
if ( entityNamesResolver == null ) {
entityNamesResolver = new SessionFactoryEntityNamesResolver( sessionFactory );
}
return entityNamesResolver;
}
}