package er.neo4jadaptor.query.neo4j_eval.retrievers;
import java.util.Iterator;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.PropertyContainer;
import org.neo4j.graphdb.Relationship;
import com.webobjects.eoaccess.EOAttribute;
import com.webobjects.eoaccess.EOEntity;
import com.webobjects.foundation.NSArray;
import er.neo4jadaptor.ersatz.neo4j.Neo4JTranslator;
import er.neo4jadaptor.query.neo4j_eval.Cost;
import er.neo4jadaptor.storage.neo4j.RelationshipStore;
import er.neo4jadaptor.utils.iteration.Iterators;
/**
* Retrieves object ID.
*
* @author Jedrzej Sobanski
*
* @param <T>
*/
public abstract class PrimaryKeyRetriever<T> implements Retriever<T, Number> {
@SuppressWarnings("unused")
private static final org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(PrimaryKeyRetriever.class);
private final EOAttribute attribute;
protected abstract long getId(T t);
public PrimaryKeyRetriever(EOAttribute att) {
this.attribute = att;
}
public Iterator<Number> retrieve(T t) {
long id = getId(t);
Number ret = (Number) Neo4JTranslator.instance.toNeutralValue(id, attribute);
return Iterators.singleton(ret);
}
@Override
public String toString() {
return attribute.name();
}
public Cost getCost() {
return Cost.PRIMARY_KEY;
}
public static PrimaryKeyRetriever<? extends PropertyContainer> create(EOEntity entity) {
NSArray<EOAttribute> pks = entity.primaryKeyAttributes();
EOAttribute pk = pks.get(0);
if (RelationshipStore.shouldBeStoredAsRelationship(entity)) {
return new PrimaryKeyRetriever<Relationship>(pk) {
@Override
protected long getId(Relationship t) {
return t.getId();
}
};
} else {
return new PrimaryKeyRetriever<Node>(pk) {
@Override
protected long getId(Node t) {
return t.getId();
}
};
}
}
}