Fix: offset scrolling - calculate query offset by page size

Signed-off-by: Artemiy Chereshnevvv <[email protected]>

Author: chrshnv

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/query/StatementFactory.java

@@ -350,8 +350,11 @@ SelectBuilder.SelectWhere applyLimitAndOffset(SelectBuilder.SelectLimitOffset li
 			}
 
 			if (mode == Mode.SCROLL && scrollPosition != null && scrollPosition instanceof OffsetScrollPosition
-					&& !scrollPosition.isInitial())
-				limitOffsetBuilder = limitOffsetBuilder.offset(((OffsetScrollPosition) scrollPosition).getOffset() + 1);
+					&& !scrollPosition.isInitial()) {
+				int pageSize = limit.isLimited() ? limit.max() : Integer.MAX_VALUE;
+
+				limitOffsetBuilder = limitOffsetBuilder.offset(((OffsetScrollPosition) scrollPosition).getOffset() * pageSize);
+			}
 
 			return (SelectBuilder.SelectWhere) limitOffsetBuilder;
 		}

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/JdbcRepositoryIntegrationTests.java

@@ -1577,6 +1577,23 @@ void queryByWindowKeySetTwoKeys() {
 		assertThat(entities).extracting("idProp").contains(five.idProp);
 	}
 
+	@Test
+	void queryByWindowOffsetPosition() {
+		DummyEntity one = repository.save(createEntity("one", it -> it.setPointInTime(Instant.ofEpochSecond(1000))));
+		DummyEntity two = repository.save(createEntity("two", it -> it.setPointInTime(Instant.ofEpochSecond(2000))));
+		DummyEntity three = repository.save(createEntity("three", it -> it.setPointInTime(Instant.ofEpochSecond(3000))));
+
+		Window<DummyEntity> result = repository.findFirst2ByOrderByIdPropAsc(ScrollPosition.offset());
+		assertSoftly(softAssertions -> {
+			softAssertions.assertThat(result.hasNext()).isTrue();
+			softAssertions.assertThat(result.size()).isEqualTo(2);
+
+			ScrollPosition position = result.positionAt(1);
+			softAssertions.assertThat(position.isInitial()).isFalse();
+			softAssertions.assertThat(((OffsetScrollPosition) position).getOffset()).isEqualTo(1);
+		});
+	}
+
 	private Root createRoot(String namePrefix) {
 
 		return new Root(null, namePrefix,