org.hibernate.transform: public class: DistinctResultTransformer

org.hibernate.transform
public class: DistinctResultTransformer [javadoc | source]

java.lang.Object
   org.hibernate.transform.BasicTransformerAdapter
      org.hibernate.transform.DistinctResultTransformer

All Implemented Interfaces:
Serializable, ResultTransformer

Distinctions the result tuples in the final result based on the defined equality of the tuples.

Since this transformer is stateless, all instances would be considered equal. So for optimization purposes we limit it to a single, singleton instance .

author: Steve - Ebersole

Field Summary
public static final DistinctResultTransformer	INSTANCE

Method from org.hibernate.transform.DistinctResultTransformer Summary:
transformList

Methods from org.hibernate.transform.BasicTransformerAdapter:
transformList, transformTuple

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.hibernate.transform.DistinctResultTransformer Detail:
public List transformList(List list) { List result = new ArrayList( list.size() ); Set distinct = new HashSet(); for ( int i = 0; i < list.size(); i++ ) { Object entity = list.get( i ); if ( distinct.add( new Identity( entity ) ) ) { result.add( entity ); } } if ( log.isDebugEnabled() ) { log.debug( "transformed: " + list.size() + " rows to: " + result.size() + " distinct results" ); } return result; } Uniquely distinct each tuple row here.

Method from org.hibernate.transform.DistinctResultTransformer Detail:

 public List transformList(List list) {
		List result = new ArrayList( list.size() );
		Set distinct = new HashSet();
		for ( int i = 0; i <  list.size(); i++ ) {
			Object entity = list.get( i );
			if ( distinct.add( new Identity( entity ) ) ) {
				result.add( entity );
			}
		}
		if ( log.isDebugEnabled() ) {
			log.debug(
					"transformed: " +
							list.size() + " rows to: " +
							result.size() + " distinct results"
			);
		}
		return result;
}

Uniquely distinct each tuple row here.