Package org.hibernate.search.backend.lucene.search.projection.impl

Interface LuceneSearchProjection.Extractor<E,P>

Type Parameters:

E - The type of temporary values extracted from the response. May be the same as LuceneSearchProjection.Extractor, or not, depending on implementation.

P - The type of projected values.

All Known Implementing Classes:

LuceneConstantProjection, LuceneEntityLoadingProjection, LuceneEntityReferenceProjection, LuceneIdProjection, LuceneThrowingProjection

Enclosing interface:

LuceneSearchProjection<P>

public static interface LuceneSearchProjection.Extractor<E,P>

An object responsible for extracting data from the Lucene Searcher, to implement a projection.

Method Summary

Modifier and Type	Method	Description
P	transform(LoadingResult<?> loadingResult, E extractedData, ProjectionTransformContext context)	Transforms the extracted data to the actual projection result.
static <Z> Z	transformUnsafe(LuceneSearchProjection.Extractor<?,Z> extractor, LoadingResult<?> loadingResult, Object extractedData, ProjectionTransformContext context)	Transforms the extracted data and casts it to the right type.
Values<E>	values(ProjectionExtractContext context)	Creates low-level values for use in a TopDocsDataCollector.

Method Detail

values

Values<E> values(ProjectionExtractContext context)

Creates low-level values for use in a TopDocsDataCollector.

The returned Values should only perform operations relative to extracting content from the index, delaying operations that rely on the mapper until transform(LoadingResult, Object, ProjectionTransformContext) is called, so that blocking mapper operations (if any) do not pollute backend threads.

Parameters:

context - An execution context for the extraction.

Returns:

The Values to use during Lucene collection of top docs data.

transform

P transform(LoadingResult<?> loadingResult,
            E extractedData,
            ProjectionTransformContext context)

Transforms the extracted data to the actual projection result.

Parameters:

loadingResult - Container containing all the entities that have been loaded by the ProjectionHitMapper.

extractedData - The extracted data to transform, returned by the value source.

context - An execution context for the transforming.

Returns:

The final result considered as a hit.

transformUnsafe

static <Z> Z transformUnsafe(LuceneSearchProjection.Extractor<?,Z> extractor,
                             LoadingResult<?> loadingResult,
                             Object extractedData,
                             ProjectionTransformContext context)

Transforms the extracted data and casts it to the right type.

This should be used with care as it's unsafe.