Interface ResultListTransformer<T>

Type Parameters:

T - The result list element type

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@Incubating
@FunctionalInterface
public interface ResultListTransformer<T>

Defines some processing performed on the overall result List of a Query before the result list is returned to the caller.

See Also:

• Query.setResultListTransformer(ResultListTransformer)
• Query.list()
• Query.getResultList()
• TupleTransformer

Method Summary

Modifier and Type	Method	Description
List<T>	transformList(List<T> resultList)	Here we have an opportunity to perform transformation on the query result as a whole.
static <T> ResultListTransformer<T>	uniqueResultTransformer()	A ResultListTransformer which collapses a list of results into a single result when all results are equal, or throws NonUniqueResultException otherwise.

Method Details

transformList

List<T> transformList(List<T> resultList)

Here we have an opportunity to perform transformation on the query result as a whole. This might be useful to convert from one collection type to another or to remove duplicates from the result, etc.

Parameters:

resultList - The result list as would otherwise be returned by the Query without the intervention of this ResultListTransformer

Returns:

The transformed result.

uniqueResultTransformer

static <T> ResultListTransformer<T> uniqueResultTransformer()

A ResultListTransformer which collapses a list of results into a single result when all results are equal, or throws NonUniqueResultException otherwise.

Type Parameters:

T - The result list element type

Since:

7.3