Supports scrolling base on keyset without id

id shouldn't be added to sort if sort property already provided.

See spring-projectsGH-2996

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

@@ -38,6 +38,7 @@
  *
  * @author Mark Paluch
  * @author Christoph Strobl
+ * @author Yanming Zhou
  * @since 3.1
  */
 public record KeysetScrollSpecification<T> (KeysetScrollPosition position, Sort sort,
@@ -61,6 +62,10 @@ public static Sort createSort(KeysetScrollPosition position, Sort sort, JpaEntit
 
 		KeysetScrollDelegate delegate = KeysetScrollDelegate.of(position.getDirection());
 
+		if (sort.isSorted()) {
+			return delegate.getSortOrders(sort);
+		}
+
 		Sort sortToUse;
 		if (entity.hasCompositeId()) {
 			sortToUse = sort.and(Sort.by(entity.getIdAttributeNames().toArray(new String[0])));

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/EntityWithoutScrollableId.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2019-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.domain.sample;
+
+import jakarta.persistence.*;
+import lombok.Data;
+import org.springframework.data.domain.Persistable;
+
+import java.util.UUID;
+
+/**
+ * @author Yanming Zhou
+ */
+@Entity
+@Data
+public class EntityWithoutScrollableId {
+
+	private @Id UUID id = UUID.randomUUID();
+
+	private @Column(unique = true) int seqNo;
+}

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

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2019-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository;
+
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.KeysetScrollPosition;
+import org.springframework.data.domain.ScrollPosition;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.domain.Window;
+import org.springframework.data.jpa.domain.sample.EntityWithoutScrollableId;
+import org.springframework.data.jpa.repository.sample.EntityWithoutScrollableIdRepository;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Yanming Zhou
+ */
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration("classpath:config/namespace-application-context.xml")
+@Transactional
+class ScrollingWithoutIdIntegrationTests {
+
+	private final static int pageSize = 10;
+
+	private final static Integer[] totals = new Integer[] { 0, 5, 10, 15, 20, 25 };
+
+	@Autowired
+	EntityWithoutScrollableIdRepository repository;
+
+	void prepare(int total) {
+		for (int i = 0; i < total; i++) {
+			EntityWithoutScrollableId entity = new EntityWithoutScrollableId();
+			entity.setSeqNo(i);
+			this.repository.save(entity);
+		}
+	}
+
+	@ParameterizedTest
+	@MethodSource("cartesian")
+	void scroll(Sort.Direction sortDirection, ScrollPosition.Direction scrollDirection, int total) {
+
+		prepare(total);
+
+		List<List<EntityWithoutScrollableId>> contents = new ArrayList<>();
+
+		String propertyName = "seqNo";
+		KeysetScrollPosition position = ScrollPosition.of(Map.of(), scrollDirection);
+		if (scrollDirection == ScrollPosition.Direction.BACKWARD && position.getDirection() == ScrollPosition.Direction.FORWARD) {
+			// remove this workaround if https://github.com/spring-projects/spring-data-commons/pull/2841 merged
+			position = position.backward();
+		}
+		while (true) {
+			ScrollPosition positionToUse = position;
+			Window<EntityWithoutScrollableId> window = this.repository.findBy((root, query, cb) -> null,
+					q -> q.limit(pageSize).sortBy(Sort.by(sortDirection, propertyName)).scroll(positionToUse));
+			if (!window.isEmpty()) {
+				contents.add(window.getContent());
+			}
+			if (!window.hasNext()) {
+				break;
+			}
+			int indexForNext = position.scrollsForward() ? window.size() - 1 : 0;
+			position = ScrollPosition.of(
+					Map.of(propertyName,window.getContent().get(indexForNext).getSeqNo()),
+					scrollDirection);
+			// position = window.positionAt(indexForNext); https://github.com/spring-projects/spring-data-jpa/pull/3000
+			// position = window.positionForNext(); https://github.com/spring-projects/spring-data-commons/pull/2843
+		}
+
+		if (total == 0) {
+			assertThat(contents).hasSize(0);
+			return;
+		}
+
+		boolean divisible = total % pageSize == 0;
+
+		assertThat(contents).hasSize(divisible ? total / pageSize : total / pageSize + 1);
+		for (int i = 0; i < contents.size() - 1; i++) {
+			assertThat(contents.get(i)).hasSize(pageSize);
+		}
+		if (divisible) {
+			assertThat(contents.get(contents.size() - 1)).hasSize(pageSize);
+		}
+		else {
+			assertThat(contents.get(contents.size() - 1)).hasSize(total % pageSize);
+		}
+
+		List<EntityWithoutScrollableId> first = contents.get(0);
+		List<EntityWithoutScrollableId> last = contents.get(contents.size() - 1);
+
+		if (sortDirection == Sort.Direction.ASC) {
+			if (scrollDirection == ScrollPosition.Direction.FORWARD) {
+				assertThat(first.get(0).getSeqNo()).isEqualTo(0);
+				assertThat(last.get(last.size() - 1).getSeqNo()).isEqualTo(total - 1);
+			}
+			else {
+				assertThat(first.get(first.size() - 1).getSeqNo()).isEqualTo(total - 1);
+				assertThat(last.get(0).getSeqNo()).isEqualTo(0);
+			}
+		}
+		else {
+			if (scrollDirection == ScrollPosition.Direction.FORWARD) {
+				assertThat(first.get(0).getSeqNo()).isEqualTo(total - 1);
+				assertThat(last.get(last.size() - 1).getSeqNo()).isEqualTo(0);
+			}
+			else {
+				assertThat(first.get(first.size() - 1).getSeqNo()).isEqualTo(0);
+				assertThat(last.get(0).getSeqNo()).isEqualTo(total - 1);
+			}
+		}
+	}
+
+	private static Stream<Arguments> cartesian() {
+		return Stream.of(Sort.Direction.class.getEnumConstants())
+				.flatMap(a -> Stream.of(ScrollPosition.Direction.class.getEnumConstants())
+						.flatMap(b -> Stream.of(totals).map(total -> Arguments.of(a, b, total))));
+	}
+}

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

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2019-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository.sample;
+
+import org.springframework.data.jpa.domain.sample.EntityWithoutScrollableId;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+import org.springframework.data.repository.CrudRepository;
+
+import java.util.UUID;
+
+/**
+ * @author Yanming Zhou
+ */
+public interface EntityWithoutScrollableIdRepository extends CrudRepository<EntityWithoutScrollableId, UUID>, JpaSpecificationExecutor<EntityWithoutScrollableId> {
+
+}

spring-data-jpa/src/test/resources/META-INF/persistence.xml

@@ -18,6 +18,7 @@
 		<class>org.springframework.data.jpa.domain.sample.ConcreteType2</class>
 		<class>org.springframework.data.jpa.domain.sample.CustomAbstractPersistable</class>
 		<class>org.springframework.data.jpa.domain.sample.Customer</class>
+		<class>org.springframework.data.jpa.domain.sample.EntityWithoutScrollableId</class>
 		<class>org.springframework.data.jpa.domain.sample.EntityWithAssignedId</class>
 		<class>org.springframework.data.jpa.domain.sample.EmbeddedIdExampleEmployeePK</class>
 		<class>org.springframework.data.jpa.domain.sample.EmbeddedIdExampleEmployee</class>

spring-data-jpa/src/test/resources/META-INF/persistence2.xml

@@ -10,6 +10,7 @@
 		<class>org.springframework.data.jpa.domain.sample.AuditableEmbeddable</class>
 		<class>org.springframework.data.jpa.domain.sample.Category</class>
 		<class>org.springframework.data.jpa.domain.sample.CustomAbstractPersistable</class>
+		<class>org.springframework.data.jpa.domain.sample.EntityWithoutScrollableId</class>
 		<class>org.springframework.data.jpa.domain.sample.EntityWithAssignedId</class>
 		<class>org.springframework.data.jpa.domain.sample.Item</class>
 		<class>org.springframework.data.jpa.domain.sample.ItemSite</class>
@@ -30,6 +31,7 @@
 		<class>org.springframework.data.jpa.domain.sample.AuditableRole</class>
 		<class>org.springframework.data.jpa.domain.sample.Category</class>
 		<class>org.springframework.data.jpa.domain.sample.CustomAbstractPersistable</class>
+		<class>org.springframework.data.jpa.domain.sample.EntityWithoutScrollableId</class>
 		<class>org.springframework.data.jpa.domain.sample.EntityWithAssignedId</class>
 		<class>org.springframework.data.jpa.domain.sample.Item</class>
 		<class>org.springframework.data.jpa.domain.sample.ItemSite</class>