Polishing.

Refactor code duplications.

See #2327

Author: mp911de

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/JpaKeysetScrollQueryCreator.java

@@ -21,8 +21,6 @@
 import jakarta.persistence.criteria.Root;
 
 import java.util.Collection;
-import java.util.LinkedHashSet;
-import java.util.Set;
 
 import org.springframework.data.domain.KeysetScrollPosition;
 import org.springframework.data.domain.Sort;
@@ -77,9 +75,7 @@ Collection<String> getRequiredSelection(Sort sort, ReturnedType returnedType) {
 
 		Sort sortToUse = KeysetScrollSpecification.createSort(scrollPosition, sort, entityInformation);
 
-		Set<String> selection = new LinkedHashSet<>(returnedType.getInputProperties());
-		sortToUse.forEach(it -> selection.add(it.getProperty()));
-
-		return selection;
+		return KeysetScrollDelegate.getProjectionInputProperties(entityInformation, returnedType.getInputProperties(),
+				sortToUse);
 	}
 }

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/KeysetScrollDelegate.java

@@ -16,14 +16,17 @@
 package org.springframework.data.jpa.repository.query;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 
 import org.springframework.data.domain.KeysetScrollPosition;
 import org.springframework.data.domain.ScrollPosition.Direction;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Order;
+import org.springframework.data.jpa.repository.support.JpaEntityInformation;
 import org.springframework.lang.Nullable;
 
 /**
@@ -47,6 +50,25 @@ public static KeysetScrollDelegate of(Direction direction) {
 		return direction == Direction.FORWARD ? FORWARD : REVERSE;
 	}
 
+	/**
+	 * Return a collection of property names required to construct a keyset selection query that include all keyset and
+	 * identifier properties required to resume keyset scrolling.
+	 *
+	 * @param entity the underlying entity.
+	 * @param projectionProperties projection property names.
+	 * @param sort sort properties.
+	 * @return a collection of property names required to construct a keyset selection query
+	 */
+	public static Collection<String> getProjectionInputProperties(JpaEntityInformation<?, ?> entity,
+			Collection<String> projectionProperties, Sort sort) {
+
+		Collection<String> properties = new LinkedHashSet<>(projectionProperties);
+		sort.forEach(it -> properties.add(it.getProperty()));
+		properties.addAll(entity.getIdAttributeNames());
+
+		return properties;
+	}
+
 	@Nullable
 	public <E, P> P createPredicate(KeysetScrollPosition keyset, Sort sort, QueryStrategy<E, P> strategy) {
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/FetchableFluentQueryByPredicate.java

@@ -20,7 +20,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.function.BiFunction;
 import java.util.function.Function;
@@ -34,6 +33,7 @@
 import org.springframework.data.domain.ScrollPosition;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Window;
+import org.springframework.data.jpa.repository.query.KeysetScrollDelegate;
 import org.springframework.data.jpa.repository.query.ScrollDelegate;
 import org.springframework.data.projection.ProjectionFactory;
 import org.springframework.data.repository.query.FluentQuery.FetchableFluentQuery;
@@ -219,13 +219,11 @@ private void applyQuerySettings(ReturnedType returnedType, int limit, AbstractJP
 
 		List<String> inputProperties = returnedType.getInputProperties();
 
-		if (returnedType.needsCustomConstruction() && !inputProperties.isEmpty()) {
+		if (returnedType.needsCustomConstruction()) {
 
 			Collection<String> requiredSelection;
 			if (scrollPosition instanceof KeysetScrollPosition && returnedType.getReturnedType().isInterface()) {
-				requiredSelection = new LinkedHashSet<>(inputProperties);
-				sort.forEach(it -> requiredSelection.add(it.getProperty()));
-				entityInformation.getIdAttributeNames().forEach(requiredSelection::add);
+				requiredSelection = KeysetScrollDelegate.getProjectionInputProperties(entityInformation, inputProperties, sort);
 			} else {
 				requiredSelection = inputProperties;
 			}

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -37,7 +37,6 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -58,6 +57,7 @@
 import org.springframework.data.jpa.provider.PersistenceProvider;
 import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.query.EscapeCharacter;
+import org.springframework.data.jpa.repository.query.KeysetScrollDelegate;
 import org.springframework.data.jpa.repository.query.KeysetScrollSpecification;
 import org.springframework.data.jpa.repository.query.QueryUtils;
 import org.springframework.data.jpa.repository.support.FetchableFluentQueryBySpecification.SpecificationScrollDelegate;
@@ -772,7 +772,7 @@ private <S extends T> TypedQuery<S> getQuery(ReturnedType returnedType, @Nullabl
 
 		List<String> inputProperties = returnedType.getInputProperties();
 
-		if (returnedType.needsCustomConstruction() && !inputProperties.isEmpty()) {
+		if (returnedType.needsCustomConstruction()) {
 			query = (CriteriaQuery) (returnedType.getReturnedType().isInterface() ? builder.createTupleQuery()
 					: builder.createQuery(returnedType.getReturnedType()));
 		} else {
@@ -781,14 +781,12 @@ private <S extends T> TypedQuery<S> getQuery(ReturnedType returnedType, @Nullabl
 
 		Root<S> root = applySpecificationToCriteria(spec, domainClass, query);
 
-		if (returnedType.needsCustomConstruction() && !inputProperties.isEmpty()) {
+		if (returnedType.needsCustomConstruction()) {
 
 			Collection<String> requiredSelection;
 
 			if (scrollPosition instanceof KeysetScrollPosition && returnedType.getReturnedType().isInterface()) {
-				requiredSelection = new LinkedHashSet<>(inputProperties);
-				sort.stream().map(Sort.Order::getProperty).forEach(requiredSelection::add);
-				entityInformation.getIdAttributeNames().forEach(requiredSelection::add);
+				requiredSelection = KeysetScrollDelegate.getProjectionInputProperties(entityInformation, inputProperties, sort);
 			} else {
 				requiredSelection = inputProperties;
 			}

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/UserRepositoryTests.java

@@ -2958,6 +2958,16 @@ void dynamicProjectionReturningList() {
 		assertThat(users).hasSize(1);
 	}
 
+	@Test // GH-2327
+	void dynamicOpenProjectionReturningList() {
+
+		flushTestUsers();
+
+		List<UserProjectionUsingSpEL> users = repository.findAsListByFirstnameLike("%O%", UserProjectionUsingSpEL.class);
+
+		assertThat(users).hasSize(1);
+	}
+
 	@Test // DATAJPA-1179
 	void duplicateSpelsWorkAsIntended() {