HSEARCH-3170 Close container value extractor bean holders as appropriate

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/dirtiness/building/impl/PojoImplicitReindexingResolverBuildingHelper.java

@@ -15,10 +15,10 @@
 
 import org.hibernate.search.mapper.pojo.dirtiness.ReindexOnUpdate;
 import org.hibernate.search.mapper.pojo.dirtiness.impl.PojoImplicitReindexingResolver;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.BoundContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorBinder;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.model.additionalmetadata.building.impl.PojoTypeAdditionalMetadataProvider;
 import org.hibernate.search.mapper.pojo.model.additionalmetadata.impl.PojoTypeAdditionalMetadata;
 import org.hibernate.search.mapper.pojo.model.path.PojoModelPathValueNode;
@@ -129,7 +129,7 @@ <T> PojoImplicitReindexingResolverBuilder<T> getOrCreateResolverBuilder(
 		return extractorBinder.bindPath( typeModel, extractorPath );
 	}
 
-	<V, T> ContainerValueExtractor<? super T, V> createExtractors(
+	<V, T> ContainerValueExtractorHolder<T, V> createExtractors(
 			BoundContainerValueExtractorPath<T, V> boundExtractorPath) {
 		return extractorBinder.create( boundExtractorPath );
 	}

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/dirtiness/building/impl/PojoImplicitReindexingResolverContainerElementNodeBuilder.java

@@ -12,7 +12,7 @@
 
 import org.hibernate.search.mapper.pojo.dirtiness.impl.PojoImplicitReindexingResolverNode;
 import org.hibernate.search.mapper.pojo.dirtiness.impl.PojoImplicitReindexingResolverContainerElementNode;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.model.path.PojoModelPathValueNode;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathValueNode;
 import org.hibernate.search.mapper.pojo.model.path.spi.PojoPathFilterFactory;
@@ -22,15 +22,15 @@ class PojoImplicitReindexingResolverContainerElementNodeBuilder<C, V>
 		extends AbstractPojoImplicitReindexingResolverNodeBuilder<C> {
 
 	private final BoundPojoModelPathValueNode<?, ? extends C, V> modelPath;
-	private final ContainerValueExtractor<C, V> extractor;
+	private final ContainerValueExtractorHolder<C, V> extractorHolder;
 	private final PojoImplicitReindexingResolverValueNodeBuilderDelegate<V> valueBuilderDelegate;
 
 	PojoImplicitReindexingResolverContainerElementNodeBuilder(BoundPojoModelPathValueNode<?, ? extends C, V> modelPath,
-			ContainerValueExtractor<C, V> extractor,
+			ContainerValueExtractorHolder<C, V> extractorHolder,
 			PojoImplicitReindexingResolverBuildingHelper buildingHelper) {
 		super( buildingHelper );
 		this.modelPath = modelPath;
-		this.extractor = extractor;
+		this.extractorHolder = extractorHolder;
 		this.valueBuilderDelegate =
 				new PojoImplicitReindexingResolverValueNodeBuilderDelegate<>( modelPath, buildingHelper );
 	}
@@ -43,7 +43,7 @@ class PojoImplicitReindexingResolverContainerElementNodeBuilder<C, V>
 	@Override
 	void closeOnFailure() {
 		try ( Closer<RuntimeException> closer = new Closer<>() ) {
-			// TODO HSEARCH-3170 release the extractor beans
+			closer.push( ContainerValueExtractorHolder::close, extractorHolder );
 			closer.push( PojoImplicitReindexingResolverValueNodeBuilderDelegate::closeOnFailure, valueBuilderDelegate );
 		}
 	}
@@ -73,7 +73,7 @@ <S> Optional<PojoImplicitReindexingResolverNode<C, S>> doBuild(PojoPathFilterFac
 		}
 		else {
 			return Optional.of( new PojoImplicitReindexingResolverContainerElementNode<>(
-					extractor, valueTypeNodes
+					extractorHolder, valueTypeNodes
 			) );
 		}
 	}

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/dirtiness/building/impl/PojoImplicitReindexingResolverPropertyNodeBuilder.java

@@ -16,9 +16,9 @@
 
 import org.hibernate.search.mapper.pojo.dirtiness.impl.PojoImplicitReindexingResolverNode;
 import org.hibernate.search.mapper.pojo.dirtiness.impl.PojoImplicitReindexingResolverPropertyNode;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.BoundContainerValueExtractorPath;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.model.path.PojoModelPathValueNode;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathPropertyNode;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathValueNode;
@@ -141,11 +141,11 @@ <S> Optional<PojoImplicitReindexingResolverNode<T, S>> doBuild(PojoPathFilterFac
 	 */
 	private <V> PojoImplicitReindexingResolverContainerElementNodeBuilder<? super P, V>
 			createContainerBuilder(BoundContainerValueExtractorPath<P, V> boundExtractorPath) {
-		ContainerValueExtractor<? super P, V> extractor =
+		ContainerValueExtractorHolder<P, V> extractorHolder =
 				buildingHelper.createExtractors( boundExtractorPath );
 		BoundPojoModelPathValueNode<T, P, V> containerElementPath = modelPath.value( boundExtractorPath );
 		return new PojoImplicitReindexingResolverContainerElementNodeBuilder<>(
-				containerElementPath, extractor, buildingHelper
+				containerElementPath, extractorHolder, buildingHelper
 		);
 	}
 

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/dirtiness/impl/PojoImplicitReindexingResolverContainerElementNode.java

@@ -9,7 +9,7 @@
 import java.util.Collection;
 import java.util.stream.Stream;
 
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.model.spi.PojoRuntimeIntrospector;
 import org.hibernate.search.util.impl.common.Closer;
 import org.hibernate.search.util.impl.common.ToStringTreeBuilder;
@@ -30,27 +30,27 @@
 public class PojoImplicitReindexingResolverContainerElementNode<C, S, V>
 		extends PojoImplicitReindexingResolverNode<C, S> {
 
-	private final ContainerValueExtractor<C, V> extractor;
+	private final ContainerValueExtractorHolder<C, V> extractorHolder;
 	private final Collection<PojoImplicitReindexingResolverNode<V, S>> nestedNodes;
 
-	public PojoImplicitReindexingResolverContainerElementNode(ContainerValueExtractor<C, V> extractor,
+	public PojoImplicitReindexingResolverContainerElementNode(ContainerValueExtractorHolder<C, V> extractorHolder,
 			Collection<PojoImplicitReindexingResolverNode<V, S>> nestedNodes) {
-		this.extractor = extractor;
+		this.extractorHolder = extractorHolder;
 		this.nestedNodes = nestedNodes;
 	}
 
 	@Override
 	public void close() {
 		try ( Closer<RuntimeException> closer = new Closer<>() ) {
-			// TODO HSEARCH-3170 release the extractor beans
+			closer.push( ContainerValueExtractorHolder::close, extractorHolder );
 			closer.pushAll( PojoImplicitReindexingResolverNode::close, nestedNodes );
 		}
 	}
 
 	@Override
 	public void appendTo(ToStringTreeBuilder builder) {
 		builder.attribute( "class", getClass().getSimpleName() );
-		builder.attribute( "extractor", extractor );
+		builder.attribute( "extractor", extractorHolder.get() );
 		builder.startList( "nestedNodes" );
 		for ( PojoImplicitReindexingResolverNode<?, ?> nestedNode : nestedNodes ) {
 			builder.value( nestedNode );
@@ -61,7 +61,7 @@ public void appendTo(ToStringTreeBuilder builder) {
 	@Override
 	public void resolveEntitiesToReindex(PojoReindexingCollector collector,
 			PojoRuntimeIntrospector runtimeIntrospector, C dirty, S dirtinessState) {
-		try ( Stream<V> stream = extractor.extract( dirty ) ) {
+		try ( Stream<V> stream = extractorHolder.get().extract( dirty ) ) {
 			stream.forEach( containerElement -> resolveEntitiesToReindexForContainerElement(
 					collector, runtimeIntrospector, containerElement, dirtinessState
 			) );

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/extractor/impl/ContainerValueExtractorBinder.java

@@ -14,6 +14,7 @@
 import java.util.Map;
 import java.util.Optional;
 
+import org.hibernate.search.engine.environment.bean.BeanHolder;
 import org.hibernate.search.engine.environment.bean.BeanProvider;
 import org.hibernate.search.engine.mapper.mapping.spi.MappingBuildContext;
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
@@ -33,6 +34,7 @@
 import org.hibernate.search.mapper.pojo.util.impl.GenericTypeContext;
 import org.hibernate.search.util.AssertionFailure;
 import org.hibernate.search.util.impl.common.LoggerFactory;
+import org.hibernate.search.util.impl.common.SuppressingCloser;
 
 /**
  * Binds {@link ContainerValueExtractorPath}s to a given input type,
@@ -165,28 +167,37 @@ public ContainerValueExtractorBinder(MappingBuildContext buildContext,
 	 */
 	// Checks are performed using reflection when building the resolved path
 	@SuppressWarnings( {"rawtypes", "unchecked"} )
-	public <C, V> ContainerValueExtractor<? super C, V> create(BoundContainerValueExtractorPath<C, V> boundPath) {
+	public <C, V> ContainerValueExtractorHolder<C, V> create(BoundContainerValueExtractorPath<C, V> boundPath) {
 		if ( boundPath.getExtractorPath().isEmpty() ) {
 			throw new AssertionFailure(
 					"Received a request to create extractors, but the extractor path was empty."
 							+ " There is probably a bug in Hibernate Search."
 			);
 		}
 		ContainerValueExtractor<? super C, ?> extractor = null;
-		for ( Class<? extends ContainerValueExtractor> extractorClass :
-				boundPath.getExtractorPath().getExplicitExtractorClasses() ) {
-			// TODO HSEARCH-3170 properly handle the release of container value extractor beans
-			ContainerValueExtractor<?, ?> newExtractor =
-					beanProvider.getBean( extractorClass ).get();
-			if ( extractor == null ) {
-				// First extractor: must be able to process type C
-				extractor = (ContainerValueExtractor<? super C, ?>) newExtractor;
-			}
-			else {
-				extractor = new ChainingContainerValueExtractor( extractor, newExtractor );
+		List<BeanHolder<?>> beanHolders = new ArrayList<>();
+		try {
+			for ( Class<? extends ContainerValueExtractor> extractorClass :
+					boundPath.getExtractorPath().getExplicitExtractorClasses() ) {
+				BeanHolder<? extends ContainerValueExtractor> newExtractorHolder =
+						beanProvider.getBean( extractorClass );
+				beanHolders.add( newExtractorHolder );
+				if ( extractor == null ) {
+					// First extractor: must be able to process type C
+					extractor = (ContainerValueExtractor<? super C, ?>) newExtractorHolder.get();
+				}
+				else {
+					extractor = new ChainingContainerValueExtractor( extractor, newExtractorHolder.get() );
+				}
 			}
+			return new ContainerValueExtractorHolder<>(
+					(ContainerValueExtractor<? super C, V>) extractor, beanHolders
+			);
+		}
+		catch (RuntimeException e) {
+			new SuppressingCloser( e ).pushAll( BeanHolder::close, beanHolders );
+			throw e;
 		}
-		return (ContainerValueExtractor<C, V>) extractor;
 	}
 
 	public boolean isDefaultExtractorPath(PojoGenericTypeModel<?> sourceType, ContainerValueExtractorPath extractorPath) {

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/mapping/building/impl/PojoIndexModelBinder.java

@@ -23,6 +23,7 @@
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.BoundContainerValueExtractorPath;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathPropertyNode;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathTypeNode;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathValueNode;
@@ -47,7 +48,7 @@ public interface PojoIndexModelBinder {
 	<C> BoundContainerValueExtractorPath<C, ?> bindExtractorPath(
 			PojoGenericTypeModel<C> pojoGenericTypeModel, ContainerValueExtractorPath extractorPath);
 
-	<C, V> ContainerValueExtractor<? super C, V> createExtractors(
+	<C, V> ContainerValueExtractorHolder<C, V> createExtractors(
 			BoundContainerValueExtractorPath<C, V> boundExtractorPath);
 
 	<I> BeanHolder<? extends IdentifierBridge<I>> addIdentifierBridge(BoundPojoModelPathPropertyNode<?, I> modelPath,

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/mapping/building/impl/PojoIndexModelBinderImpl.java

@@ -31,10 +31,10 @@
 import org.hibernate.search.mapper.pojo.bridge.impl.BridgeResolver;
 import org.hibernate.search.mapper.pojo.bridge.mapping.BridgeBuildContext;
 import org.hibernate.search.mapper.pojo.bridge.mapping.BridgeBuilder;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.BoundContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorBinder;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.logging.impl.Log;
 import org.hibernate.search.mapper.pojo.model.additionalmetadata.building.impl.PojoTypeAdditionalMetadataProvider;
 import org.hibernate.search.mapper.pojo.model.impl.PojoModelPropertyRootElement;
@@ -78,7 +78,7 @@ public class PojoIndexModelBinderImpl implements PojoIndexModelBinder {
 	}
 
 	@Override
-	public <C, V> ContainerValueExtractor<? super C, V> createExtractors(
+	public <C, V> ContainerValueExtractorHolder<C, V> createExtractors(
 			BoundContainerValueExtractorPath<C, V> boundExtractorPath) {
 		return extractorBinder.create( boundExtractorPath );
 	}

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/processing/building/impl/PojoIndexingProcessorContainerElementNodeBuilder.java

@@ -11,12 +11,13 @@
 
 import org.hibernate.search.engine.mapper.mapping.building.spi.IndexModelBindingContext;
 import org.hibernate.search.mapper.pojo.dirtiness.building.impl.PojoIndexingDependencyCollectorPropertyNode;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.mapping.building.spi.PojoMappingCollectorValueNode;
 import org.hibernate.search.mapper.pojo.mapping.building.impl.PojoMappingHelper;
 import org.hibernate.search.mapper.pojo.model.path.impl.BoundPojoModelPathValueNode;
 import org.hibernate.search.mapper.pojo.processing.impl.PojoIndexingProcessor;
 import org.hibernate.search.mapper.pojo.processing.impl.PojoIndexingProcessorContainerElementNode;
+import org.hibernate.search.util.impl.common.Closer;
 
 /**
  * A builder of {@link PojoIndexingProcessorContainerElementNode}.
@@ -28,16 +29,16 @@
 class PojoIndexingProcessorContainerElementNodeBuilder<P extends C, C, V> extends AbstractPojoProcessorNodeBuilder {
 
 	private final BoundPojoModelPathValueNode<?, P, V> modelPath;
-	private final ContainerValueExtractor<C, V> extractor;
+	private final ContainerValueExtractorHolder<C, V> extractorHolder;
 
 	private final PojoIndexingProcessorValueNodeBuilderDelegate<P, V> valueNodeProcessorCollectionBuilder;
 
 	PojoIndexingProcessorContainerElementNodeBuilder(BoundPojoModelPathValueNode<?, P, V> modelPath,
-			ContainerValueExtractor<C, V> extractor,
+			ContainerValueExtractorHolder<C, V> extractorHolder,
 			PojoMappingHelper mappingHelper, IndexModelBindingContext bindingContext) {
 		super( mappingHelper, bindingContext );
 		this.modelPath = modelPath;
-		this.extractor = extractor;
+		this.extractorHolder = extractorHolder;
 
 		valueNodeProcessorCollectionBuilder = new PojoIndexingProcessorValueNodeBuilderDelegate<>(
 				modelPath,
@@ -56,7 +57,13 @@ public PojoMappingCollectorValueNode value() {
 
 	@Override
 	void closeOnFailure() {
-		valueNodeProcessorCollectionBuilder.closeOnFailure();
+		try ( Closer<RuntimeException> closer = new Closer<>() ) {
+			closer.pushAll( ContainerValueExtractorHolder::close, extractorHolder );
+			closer.pushAll(
+					PojoIndexingProcessorValueNodeBuilderDelegate::closeOnFailure,
+					valueNodeProcessorCollectionBuilder
+			);
+		}
 	}
 
 	Optional<PojoIndexingProcessorContainerElementNode<C, V>> build(
@@ -78,13 +85,15 @@ private Optional<PojoIndexingProcessorContainerElementNode<C, V>> doBuild(
 		if ( immutableNestedProcessors.isEmpty() ) {
 			/*
 			 * If this processor doesn't have any bridge, nor any nested processor,
-			 * it is useless and we don't need to build it
+			 * it is useless and we don't need to build it.
+			 * Release the other resources (the container value extractors) and return.
 			 */
+			extractorHolder.close();
 			return Optional.empty();
 		}
 		else {
 			return Optional.of( new PojoIndexingProcessorContainerElementNode<>(
-					extractor, immutableNestedProcessors
+					extractorHolder, immutableNestedProcessors
 			) );
 		}
 	}

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/processing/building/impl/PojoIndexingProcessorPropertyNodeBuilder.java

@@ -21,9 +21,9 @@
 import org.hibernate.search.mapper.pojo.bridge.mapping.BridgeBuilder;
 import org.hibernate.search.mapper.pojo.dirtiness.building.impl.PojoIndexingDependencyCollectorPropertyNode;
 import org.hibernate.search.mapper.pojo.dirtiness.building.impl.PojoIndexingDependencyCollectorTypeNode;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
 import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractorPath;
 import org.hibernate.search.mapper.pojo.extractor.impl.BoundContainerValueExtractorPath;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.mapping.building.impl.BoundPropertyBridge;
 import org.hibernate.search.mapper.pojo.mapping.building.impl.PojoIdentityMappingCollector;
 import org.hibernate.search.mapper.pojo.mapping.building.impl.PojoMappingHelper;
@@ -124,11 +124,11 @@ public PojoMappingCollectorValueNode value(ContainerValueExtractorPath extractor
 	 */
 	private <V> PojoIndexingProcessorContainerElementNodeBuilder<P, ? super P, V> createContainerElementNodeBuilder(
 			BoundContainerValueExtractorPath<P, V> boundExtractorPath) {
-		ContainerValueExtractor<? super P, V> extractor =
-				mappingHelper.getIndexModelBinder().createExtractors( boundExtractorPath );
 		BoundPojoModelPathValueNode<T, P, V> containerElementPath = modelPath.value( boundExtractorPath );
+		ContainerValueExtractorHolder<P, V> extractorHolder =
+				mappingHelper.getIndexModelBinder().createExtractors( boundExtractorPath );
 		return new PojoIndexingProcessorContainerElementNodeBuilder<>(
-				containerElementPath, extractor,
+				containerElementPath, extractorHolder,
 				mappingHelper, bindingContext
 		);
 	}

mapper/pojo/src/main/java/org/hibernate/search/mapper/pojo/processing/impl/PojoIndexingProcessorContainerElementNode.java

@@ -10,7 +10,7 @@
 import java.util.stream.Stream;
 
 import org.hibernate.search.engine.backend.document.DocumentElement;
-import org.hibernate.search.mapper.pojo.extractor.ContainerValueExtractor;
+import org.hibernate.search.mapper.pojo.extractor.impl.ContainerValueExtractorHolder;
 import org.hibernate.search.mapper.pojo.session.context.spi.AbstractPojoSessionContextImplementor;
 import org.hibernate.search.util.impl.common.Closer;
 import org.hibernate.search.util.impl.common.ToStringTreeBuilder;
@@ -24,26 +24,27 @@
  */
 public class PojoIndexingProcessorContainerElementNode<C, V> extends PojoIndexingProcessor<C> {
 
-	private final ContainerValueExtractor<C, V> extractor;
+	private final ContainerValueExtractorHolder<C, V> extractorHolder;
 	private final Collection<PojoIndexingProcessor<? super V>> nestedNodes;
 
-	public PojoIndexingProcessorContainerElementNode(ContainerValueExtractor<C, V> extractor,
+	public PojoIndexingProcessorContainerElementNode(ContainerValueExtractorHolder<C, V> extractorHolder,
 			Collection<PojoIndexingProcessor<? super V>> nestedNodes) {
-		this.extractor = extractor;
+		this.extractorHolder = extractorHolder;
 		this.nestedNodes = nestedNodes;
 	}
 
 	@Override
 	public void close() {
 		try ( Closer<RuntimeException> closer = new Closer<>() ) {
+			closer.push( ContainerValueExtractorHolder::close, extractorHolder );
 			closer.pushAll( PojoIndexingProcessor::close, nestedNodes );
 		}
 	}
 
 	@Override
 	public void appendTo(ToStringTreeBuilder builder) {
 		builder.attribute( "class", getClass().getSimpleName() );
-		builder.attribute( "extractor", extractor );
+		builder.attribute( "extractor", extractorHolder.get() );
 		builder.startList( "nestedNodes" );
 		for ( PojoIndexingProcessor<?> nestedNode : nestedNodes ) {
 			builder.value( nestedNode );
@@ -53,7 +54,7 @@ public void appendTo(ToStringTreeBuilder builder) {
 
 	@Override
 	public final void process(DocumentElement target, C source, AbstractPojoSessionContextImplementor sessionContext) {
-		try ( Stream<V> stream = extractor.extract( source ) ) {
+		try ( Stream<V> stream = extractorHolder.get().extract( source ) ) {
 			stream.forEach( sourceItem -> processItem( target, sourceItem, sessionContext ) );
 		}
 	}