/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* 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.transform;
import java.util.HashMap;
import java.util.Map;
/**
* {@link ResultTransformer} implementation which builds a map for each "row",
* made up of each aliased value where the alias is the map key.
* <p/>
* Since this transformer is stateless, all instances would be considered equal.
* So for optimization purposes we limit it to a single, singleton {@link #INSTANCE instance}.
*
* @author Gavin King
* @author Steve Ebersole
*/
public class AliasToEntityMapResultTransformer extends AliasedTupleSubsetResultTransformer {
public static final AliasToEntityMapResultTransformer INSTANCE = new AliasToEntityMapResultTransformer();
/**
* Disallow instantiation of AliasToEntityMapResultTransformer.
*/
private AliasToEntityMapResultTransformer() {
}
@Override
public Object transformTuple(Object[] tuple, String[] aliases) {
Map result = new HashMap(tuple.length);
for ( int i=0; i<tuple.length; i++ ) {
String alias = aliases[i];
if ( alias!=null ) {
result.put( alias, tuple[i] );
}
}
return result;
}
@Override
public boolean isTransformedValueATupleElement(String[] aliases, int tupleLength) {
return false;
}
/**
* Serialization hook for ensuring singleton uniqueing.
*
* @return The singleton instance : {@link #INSTANCE}
*/
private Object readResolve() {
return INSTANCE;
}
}