Polishing.

Fix also offset scroll position.

Author: mp911de

src/main/java/org/springframework/data/domain/KeysetScrollPosition.java

@@ -29,7 +29,7 @@
  * @author Mark Paluch
  * @since 3.1
  */
-public class KeysetScrollPosition implements ScrollPosition {
+public final class KeysetScrollPosition implements ScrollPosition {
 
 	private static final KeysetScrollPosition initial = new KeysetScrollPosition(Collections.emptyMap(),
 			Direction.Forward);

src/main/java/org/springframework/data/domain/OffsetScrollPosition.java

@@ -17,6 +17,7 @@
 
 import java.util.function.IntFunction;
 
+import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -25,7 +26,7 @@
  * @author Mark Paluch
  * @since 3.1
  */
-public class OffsetScrollPosition implements ScrollPosition {
+public final class OffsetScrollPosition implements ScrollPosition {
 
 	private static final OffsetScrollPosition initial = new OffsetScrollPosition(0);
 
@@ -60,18 +61,16 @@ public static OffsetScrollPosition of(long offset) {
 	}
 
 	/**
-	 * Returns the {@link IntFunction position function} to calculate
+	 * Returns the {@link IntFunction position function} to calculate.
 	 *
-	 * @return
+	 * @param startOffset the start offset to be used. Must not be negative.
+	 * @return the offset-based position function.
 	 */
 	public static IntFunction<OffsetScrollPosition> positionFunction(long startOffset) {
-		return offset -> {
-			if (offset < 0) {
-				throw new IndexOutOfBoundsException(offset);
-			}
 
-			return of(offset);
-		};
+		Assert.isTrue(startOffset >= 0, "Start offset must not be negative");
+
+		return startOffset == 0 ? OffsetPositionFunction.ZERO : new OffsetPositionFunction(startOffset);
 	}
 
 	@Override
@@ -110,4 +109,19 @@ public int hashCode() {
 	public String toString() {
 		return String.format("OffsetScrollPosition [%s]", offset);
 	}
+
+	private record OffsetPositionFunction(long startOffset) implements IntFunction<OffsetScrollPosition> {
+
+		static final OffsetPositionFunction ZERO = new OffsetPositionFunction(0);
+
+		@Override
+		public OffsetScrollPosition apply(int offset) {
+
+			if (offset < 0) {
+				throw new IndexOutOfBoundsException(offset);
+			}
+
+			return of(startOffset + offset + 1);
+		}
+	}
 }

src/main/java/org/springframework/data/domain/ScrollImpl.java

@@ -114,6 +114,6 @@ public int hashCode() {
 
 	@Override
 	public String toString() {
-		return "CursorWindow " + items;
+		return "Scroll " + items;
 	}
 }

src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java

@@ -96,6 +96,12 @@ protected Object[] getValues() {
 	public ScrollPosition getScrollPosition() {
 
 		if (!parameters.hasScrollPositionParameter()) {
+
+			Pageable pageable = getPageable();
+			if (pageable.isPaged()) {
+				return pageable.toScrollPosition();
+			}
+
 			return null;
 		}
 

src/main/java/org/springframework/data/repository/query/QueryMethod.java

@@ -109,7 +109,8 @@ public QueryMethod(Method method, RepositoryMetadata metadata, ProjectionFactory
 		}
 
 		if (isScrollQuery()) {
-			Assert.isTrue(this.parameters.hasScrollPositionParameter(),
+
+			Assert.isTrue(this.parameters.hasScrollPositionParameter() || this.parameters.hasPageableParameter(),
 					String.format("Scroll query needs to have a ScrollPosition parameter; Offending method: %s", method));
 		}
 

src/test/java/org/springframework/data/domain/KeysetScrollPositionUnitTests.java

@@ -35,7 +35,7 @@ void equalsAndHashCode() {
 		KeysetScrollPosition foo1 = KeysetScrollPosition.of(Collections.singletonMap("k", "v"));
 		KeysetScrollPosition foo2 = KeysetScrollPosition.of(Collections.singletonMap("k", "v"));
 		KeysetScrollPosition bar = KeysetScrollPosition.of(Collections.singletonMap("k", "v"), Direction.Backward);
-		System.out.println(bar);
+
 		assertThat(foo1).isEqualTo(foo2).hasSameClassAs(foo2);
 		assertThat(foo1).isNotEqualTo(bar).doesNotHaveSameHashCodeAs(bar);
 	}

src/test/java/org/springframework/data/domain/OffsetScrollPositionUnitTests.java

@@ -16,6 +16,7 @@
 package org.springframework.data.domain;
 
 import static org.assertj.core.api.Assertions.*;
+import static org.springframework.data.domain.OffsetScrollPosition.*;
 
 import org.junit.jupiter.api.Test;
 
@@ -36,4 +37,14 @@ void equalsAndHashCode() {
 		assertThat(foo1).isEqualTo(foo2).hasSameClassAs(foo2);
 		assertThat(foo1).isNotEqualTo(bar).doesNotHaveSameHashCodeAs(bar);
 	}
+
+	@Test // GH-2151
+	void shouldCreateCorrectIndexPosition() {
+
+		assertThat(positionFunction(0).apply(0)).isEqualTo(OffsetScrollPosition.of(1));
+		assertThat(positionFunction(0).apply(1)).isEqualTo(OffsetScrollPosition.of(2));
+
+		assertThat(positionFunction(100).apply(0)).isEqualTo(OffsetScrollPosition.of(101));
+		assertThat(positionFunction(100).apply(1)).isEqualTo(OffsetScrollPosition.of(102));
+	}
 }

src/test/java/org/springframework/data/domain/ScrollUnitTests.java

@@ -57,13 +57,13 @@ void shouldCreateCorrectPositions() {
 
 		Scroll<Integer> scroll = Scroll.from(List.of(1, 2, 3), OffsetScrollPosition.positionFunction(0));
 
-		assertThat(scroll.firstPosition()).isEqualTo(OffsetScrollPosition.initial());
-		assertThat(scroll.lastPosition()).isEqualTo(OffsetScrollPosition.of(2));
+		assertThat(scroll.firstPosition()).isEqualTo(OffsetScrollPosition.of(1));
+		assertThat(scroll.lastPosition()).isEqualTo(OffsetScrollPosition.of(3));
 
 		// by index
-		assertThat(scroll.positionAt(1)).isEqualTo(OffsetScrollPosition.of(1));
+		assertThat(scroll.positionAt(1)).isEqualTo(OffsetScrollPosition.of(2));
 
 		// by object
-		assertThat(scroll.positionAt(Integer.valueOf(1))).isEqualTo(OffsetScrollPosition.of(0));
+		assertThat(scroll.positionAt(Integer.valueOf(1))).isEqualTo(OffsetScrollPosition.of(1));
 	}
 }