DATAJDBC-291 - Polishing.

Introduce factory methods for AggregateChange save/delete object creation. Replace computeIfAbsent pattern with appropriate methods. Add indirection for staged values traversal. Rename CascadingValuesLookup to StagedValues.
Javadoc, formatting.

Original pull request: #173.

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateTemplate.java

@@ -26,7 +26,6 @@ import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
 import org.springframework.data.mapping.IdentifierAccessor;
 import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.conversion.AggregateChange;
-import org.springframework.data.relational.core.conversion.AggregateChange.Kind;
 import org.springframework.data.relational.core.conversion.Interpreter;
 import org.springframework.data.relational.core.conversion.RelationalConverter;
 import org.springframework.data.relational.core.conversion.RelationalEntityDeleteWriter;
@@ -331,33 +330,30 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		triggerAfterDelete(entity, id, change);
 	}
 
-	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private <T> AggregateChange<T> createInsertChange(T instance) {
 
-		AggregateChange<T> aggregateChange = new AggregateChange(Kind.SAVE, instance.getClass(), instance);
+		AggregateChange<T> aggregateChange = AggregateChange.forSave(instance);
 		jdbcEntityInsertWriter.write(instance, aggregateChange);
 		return aggregateChange;
 	}
 
-	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private <T> AggregateChange<T> createUpdateChange(T instance) {
 
-		AggregateChange<T> aggregateChange = new AggregateChange(Kind.SAVE, instance.getClass(), instance);
+		AggregateChange<T> aggregateChange = AggregateChange.forSave(instance);
 		jdbcEntityUpdateWriter.write(instance, aggregateChange);
 		return aggregateChange;
 	}
 
-	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private <T> AggregateChange<T> createDeletingChange(Object id, @Nullable T entity, Class<T> domainType) {
 
-		AggregateChange<T> aggregateChange = new AggregateChange(Kind.DELETE, domainType, entity);
+		AggregateChange<T> aggregateChange = AggregateChange.forDelete(domainType, entity);
 		jdbcEntityDeleteWriter.write(id, aggregateChange);
 		return aggregateChange;
 	}
 
 	private AggregateChange<?> createDeletingChange(Class<?> domainType) {
 
-		AggregateChange<?> aggregateChange = new AggregateChange<>(Kind.DELETE, domainType, null);
+		AggregateChange<?> aggregateChange = AggregateChange.forDelete(domainType, null);
 		jdbcEntityDeleteWriter.write(null, aggregateChange);
 		return aggregateChange;
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/core/conversion/AggregateChange.java

@@ -25,6 +25,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.BiConsumer;
 
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
@@ -34,6 +35,7 @@ import org.springframework.data.relational.core.mapping.RelationalPersistentEnti
 import org.springframework.data.util.Pair;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * Represents the change happening to the aggregate (as used in the context of Domain Driven Design) as a whole.
@@ -59,7 +61,53 @@ public class AggregateChange<T> {
 		this.entity = entity;
 	}
 
+	/**
+	 * Factory method to create an {@link AggregateChange} for saving entities.
+	 *
+	 * @param entity aggregate root to save.
+	 * @param <T> entity type.
+	 * @return the {@link AggregateChange} for saving the root {@code entity}.
+	 * @since 1.2
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T> AggregateChange<T> forSave(T entity) {
+
+		Assert.notNull(entity, "Entity must not be null");
+		return new AggregateChange<>(Kind.SAVE, (Class<T>) ClassUtils.getUserClass(entity), entity);
+	}
+
+	/**
+	 * Factory method to create an {@link AggregateChange} for deleting entities.
+	 *
+	 * @param entity aggregate root to delete.
+	 * @param <T> entity type.
+	 * @return the {@link AggregateChange} for deleting the root {@code entity}.
+	 * @since 1.2
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T> AggregateChange<T> forDelete(T entity) {
+
+		Assert.notNull(entity, "Entity must not be null");
+		return forDelete((Class<T>) ClassUtils.getUserClass(entity), entity);
+	}
+
+	/**
+	 * Factory method to create an {@link AggregateChange} for deleting entities.
+	 *
+	 * @param entityClass aggregate root type.
+	 * @param entity aggregate root to delete.
+	 * @param <T> entity type.
+	 * @return the {@link AggregateChange} for deleting the root {@code entity}.
+	 * @since 1.2
+	 */
+	public static <T> AggregateChange<T> forDelete(Class<T> entityClass, @Nullable T entity) {
+
+		Assert.notNull(entityClass, "Entity class must not be null");
+		return new AggregateChange<>(Kind.DELETE, entityClass, entity);
+	}
+
 	public void setEntity(@Nullable T aggregateRoot) {
+		// TODO: Check instanceOf compatibility to ensure type contract.
 		entity = aggregateRoot;
 	}
 
@@ -67,16 +115,15 @@ public class AggregateChange<T> {
 
 		actions.forEach(action -> action.executeWith(interpreter));
 
-		T newRoot = setGeneratedIds(context, converter);
+		T newRoot = populateIdsIfNecessary(context, converter);
 
 		if (newRoot != null) {
 			entity = newRoot;
 		}
 	}
 
-	@SuppressWarnings("unchecked")
 	@Nullable
-	private T setGeneratedIds(RelationalMappingContext context, RelationalConverter converter) {
+	private T populateIdsIfNecessary(RelationalMappingContext context, RelationalConverter converter) {
 
 		T newRoot = null;
 
@@ -84,32 +131,31 @@ public class AggregateChange<T> {
 		ArrayList<DbAction<?>> reverseActions = new ArrayList<>(actions);
 		Collections.reverse(reverseActions);
 
-		CascadingValuesLookup cascadingValues = new CascadingValuesLookup();
+		StagedValues cascadingValues = new StagedValues();
 
 		for (DbAction<?> action : reverseActions) {
 
-			if (action instanceof DbAction.WithGeneratedId) {
+			if (!(action instanceof DbAction.WithGeneratedId)) {
-
+				continue;
-				DbAction.WithGeneratedId<?> withGeneratedId = (DbAction.WithGeneratedId<?>) action;
+			}
-				Object generatedId = withGeneratedId.getGeneratedId();
 
-				Object newEntity = setIdAndCascadingProperties(context, converter, withGeneratedId, generatedId,
+			DbAction.WithGeneratedId<?> withGeneratedId = (DbAction.WithGeneratedId<?>) action;
-						cascadingValues);
+			Object generatedId = withGeneratedId.getGeneratedId();
+			Object newEntity = setIdAndCascadingProperties(context, converter, withGeneratedId, generatedId, cascadingValues);
 
-				// the id property was immutable so we have to propagate changes up the tree
+			// the id property was immutable so we have to propagate changes up the tree
-				if (newEntity != ((DbAction.WithGeneratedId<?>) action).getEntity()) {
+			if (newEntity != ((DbAction.WithGeneratedId<?>) action).getEntity()) {
 
-					if (action instanceof DbAction.Insert) {
+				if (action instanceof DbAction.Insert) {
-						DbAction.Insert insert = (DbAction.Insert) action;
+					DbAction.Insert insert = (DbAction.Insert) action;
 
-						Pair qualifier = insert.getQualifier();
+					Pair qualifier = insert.getQualifier();
 
-						cascadingValues.add(insert.dependingOn, insert.propertyPath, newEntity,
+					cascadingValues.stage(insert.dependingOn, insert.propertyPath,
-								qualifier == null ? null : qualifier.getSecond());
+							qualifier == null ? null : qualifier.getSecond(), newEntity);
 
-					} else if (action instanceof DbAction.InsertRoot) {
+				} else if (action instanceof DbAction.InsertRoot) {
-						newRoot = (T) newEntity;
+					newRoot = entityType.cast(newEntity);
-					}
 				}
 			}
 		}
@@ -119,7 +165,7 @@ public class AggregateChange<T> {
 
 	@SuppressWarnings("unchecked")
 	private <S> Object setIdAndCascadingProperties(RelationalMappingContext context, RelationalConverter converter,
-			DbAction.WithGeneratedId<S> action, @Nullable Object generatedId, CascadingValuesLookup cascadingValues) {
+			DbAction.WithGeneratedId<S> action, @Nullable Object generatedId, StagedValues cascadingValues) {
 
 		S originalEntity = action.getEntity();
 
@@ -132,19 +178,14 @@ public class AggregateChange<T> {
 		}
 
 		// set values of changed immutables referenced by this entity
-		Map<PersistentPropertyPath, Object> cascadingValue = cascadingValues.get(action);
+		cascadingValues.forEachPath(action, (persistentPropertyPath, o) -> propertyAccessor
-		for (Map.Entry<PersistentPropertyPath, Object> pathValuePair : cascadingValue.entrySet()) {
+				.setProperty(getRelativePath(action, persistentPropertyPath), o));
-			propertyAccessor.setProperty(getRelativePath(action, pathValuePair), pathValuePair.getValue());
-		}
 
 		return propertyAccessor.getBean();
 	}
 
 	@SuppressWarnings("unchecked")
-	private PersistentPropertyPath getRelativePath(DbAction action,
+	private PersistentPropertyPath getRelativePath(DbAction action, PersistentPropertyPath pathToValue) {
-			Map.Entry<PersistentPropertyPath, Object> pathValuePair) {
-
-		PersistentPropertyPath pathToValue = pathValuePair.getKey();
 
 		if (action instanceof DbAction.Insert) {
 			return pathToValue.getExtensionForBaseOf(((DbAction.Insert) action).propertyPath);
@@ -178,12 +219,13 @@ public class AggregateChange<T> {
 	}
 
 	/**
-	 * Gathers and holds information about immutable properties in an aggregate that need updating.
+	 * Accumulates information about staged immutable objects in an aggregate that require updating because their state
+	 * changed because of {@link DbAction} execution.
 	 */
-	private static class CascadingValuesLookup {
+	private static class StagedValues {
 
-		static final List<MultiValueAggregator> aggregators = Arrays.asList(new SetAggregator(), new MapAggregator(),
+		static final List<MultiValueAggregator> aggregators = Arrays.asList(SetAggregator.INSTANCE, MapAggregator.INSTANCE,
-				new ListAggregator(), new SingleElementAggregator());
+				ListAggregator.INSTANCE, SingleElementAggregator.INSTANCE);
 
 		Map<DbAction, Map<PersistentPropertyPath, Object>> values = new HashMap<>();
 
@@ -194,27 +236,22 @@ public class AggregateChange<T> {
 		 * @param action The action responsible for persisting the entity that needs the added value set. Must not be
 		 *          {@literal null}.
 		 * @param path The path to the property in which to set the value. Must not be {@literal null}.
-		 * @param value The value to be set. Must not be {@literal null}.
 		 * @param qualifier If {@code path} is a qualified multivalued properties this parameter contains the qualifier. May
 		 *          be {@literal null}.
+		 * @param value The value to be set. Must not be {@literal null}.
 		 */
 		@SuppressWarnings("unchecked")
-		public <T> void add(DbAction<?> action, PersistentPropertyPath path, Object value, @Nullable Object qualifier) {
+		<T> void stage(DbAction<?> action, PersistentPropertyPath path, @Nullable Object qualifier, Object value) {
 
 			MultiValueAggregator<T> aggregator = getAggregatorFor(path);
 
-			Map<PersistentPropertyPath, Object> valuesForPath = this.values.get(action);
+			Map<PersistentPropertyPath, Object> valuesForPath = this.values.computeIfAbsent(action,
-			if (valuesForPath == null) {
+					dbAction -> new HashMap<>());
-				valuesForPath = new HashMap<>();
-				values.put(action, valuesForPath);
-			}
 
-			T currentValue = (T) valuesForPath.get(path);
+			T currentValue = (T) valuesForPath.computeIfAbsent(path,
-			if (currentValue == null) {
+					persistentPropertyPath -> aggregator.createEmptyInstance());
-				currentValue = aggregator.createEmptyInstance();
-			}
 
-			Object newValue = aggregator.add(currentValue, value, qualifier);
+			Object newValue = aggregator.add(currentValue, qualifier, value);
 
 			valuesForPath.put(path, newValue);
 		}
@@ -231,8 +268,17 @@ public class AggregateChange<T> {
 			throw new IllegalStateException(String.format("Can't handle path %s", path));
 		}
 
-		public Map<PersistentPropertyPath, Object> get(DbAction<?> action) {
+		/**
-			return values.getOrDefault(action, Collections.emptyMap());
+		 * Performs the given action for each entry in this the staging area that are provided by {@link DbAction} until all
+		 * {@link PersistentPropertyPath} have been processed or the action throws an exception. The {@link BiConsumer
+		 * action} is called with each applicable {@link PersistentPropertyPath} and {@code value} that is assignable to the
+		 * property.
+		 *
+		 * @param dbAction
+		 * @param action
+		 */
+		void forEachPath(DbAction<?> dbAction, BiConsumer<PersistentPropertyPath, Object> action) {
+			values.getOrDefault(dbAction, Collections.emptyMap()).forEach(action);
 		}
 	}
 
@@ -249,11 +295,13 @@ public class AggregateChange<T> {
 		@Nullable
 		T createEmptyInstance();
 
-		T add(@Nullable T aggregate, Object value, @Nullable Object qualifier);
+		T add(@Nullable T aggregate, @Nullable Object qualifier, Object value);
 
 	}
 
-	static private class SetAggregator implements MultiValueAggregator<Set> {
+	private enum SetAggregator implements MultiValueAggregator<Set> {
+
+		INSTANCE;
 
 		@Override
 		public Class<Set> handledType() {
@@ -267,7 +315,7 @@ public class AggregateChange<T> {
 
 		@SuppressWarnings("unchecked")
 		@Override
-		public Set add(@Nullable Set set, Object value, @Nullable Object qualifier) {
+		public Set add(@Nullable Set set, @Nullable Object qualifier, Object value) {
 
 			Assert.notNull(set, "Set must not be null");
 
@@ -276,7 +324,9 @@ public class AggregateChange<T> {
 		}
 	}
 
-	static private class ListAggregator implements MultiValueAggregator<List> {
+	private enum ListAggregator implements MultiValueAggregator<List> {
+
+		INSTANCE;
 
 		@Override
 		public boolean handles(PersistentProperty property) {
@@ -290,7 +340,7 @@ public class AggregateChange<T> {
 
 		@SuppressWarnings("unchecked")
 		@Override
-		public List add(@Nullable List list, Object value, @Nullable Object qualifier) {
+		public List add(@Nullable List list, @Nullable Object qualifier, Object value) {
 
 			Assert.notNull(list, "List must not be null.");
 
@@ -305,7 +355,9 @@ public class AggregateChange<T> {
 		}
 	}
 
-	static private class MapAggregator implements MultiValueAggregator<Map> {
+	private enum MapAggregator implements MultiValueAggregator<Map> {
+
+		INSTANCE;
 
 		@Override
 		public Class<Map> handledType() {
@@ -319,7 +371,7 @@ public class AggregateChange<T> {
 
 		@SuppressWarnings("unchecked")
 		@Override
-		public Map add(@Nullable Map map, Object value, @Nullable Object qualifier) {
+		public Map add(@Nullable Map map, @Nullable Object qualifier, Object value) {
 
 			Assert.notNull(map, "Map must not be null.");
 
@@ -328,7 +380,9 @@ public class AggregateChange<T> {
 		}
 	}
 
-	static private class SingleElementAggregator implements MultiValueAggregator<Object> {
+	private enum SingleElementAggregator implements MultiValueAggregator<Object> {
+
+		INSTANCE;
 
 		@Override
 		@Nullable
@@ -337,7 +391,7 @@ public class AggregateChange<T> {
 		}
 
 		@Override
-		public Object add(@Nullable Object __null, Object value, @Nullable Object qualifier) {
+		public Object add(@Nullable Object __null, @Nullable Object qualifier, Object value) {
 			return value;
 		}
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/core/conversion/DbAction.java

@@ -262,6 +262,9 @@ public interface DbAction<T> {
 		 */
 		Map<PersistentPropertyPath<RelationalPersistentProperty>, Object> getQualifiers();
 
+		// TODO: Encapsulate propertyPath and qualifier in object: PropertyPathWithListIndex,
+		// PropertyPathWithMapIndex, PropertyPathInSet, PropertyPathWithoutQualifier
+		// Probably we need better names.
 		@Nullable
 		default Pair<PersistentPropertyPath<RelationalPersistentProperty>, Object> getQualifier() {
 			Map<PersistentPropertyPath<RelationalPersistentProperty>, Object> qualifiers = getQualifiers();
@@ -272,14 +275,14 @@ public interface DbAction<T> {
 				throw new IllegalStateException("Can't handle more then on qualifier");
 			}
 
-			Map.Entry<PersistentPropertyPath<RelationalPersistentProperty>, Object> entry = qualifiers.entrySet().iterator().next();
+			Map.Entry<PersistentPropertyPath<RelationalPersistentProperty>, Object> entry = qualifiers.entrySet().iterator()
+					.next();
 			if (entry.getValue() == null) {
 				return null;
 			}
 			return Pair.of(entry.getKey(), entry.getValue());
 		};
 
-
 		@Override
 		default Class<T> getEntityType() {
 			return WithEntity.super.getEntityType();

spring-data-relational/src/test/java/org/springframework/data/relational/core/conversion/AggregateChangeIdGenerationImmutableUnitTests.java

@@ -18,6 +18,7 @@ package org.springframework.data.relational.core.conversion;
 import static java.util.Arrays.*;
 import static java.util.Collections.*;
 import static org.assertj.core.api.Assertions.*;
+import static org.assertj.core.api.SoftAssertions.*;
 
 import lombok.AllArgsConstructor;
 import lombok.Value;
@@ -30,8 +31,8 @@ import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.assertj.core.api.SoftAssertions;
 import org.junit.Test;
+
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mapping.PersistentPropertyPath;
 import org.springframework.data.mapping.PersistentPropertyPaths;
@@ -41,7 +42,8 @@ import org.springframework.data.relational.core.mapping.RelationalPersistentProp
 import org.springframework.lang.Nullable;
 
 /**
- * Unit tests for the {@link AggregateChange} testing the setting of generated ids in aggregates consisting of immutable entities.
+ * Unit tests for the {@link AggregateChange} testing the setting of generated ids in aggregates consisting of immutable
+ * entities.
  *
  * @author Jens Schauder
  * @author Myeonghyeon-Lee
@@ -59,14 +61,12 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 	RelationalMappingContext context = new RelationalMappingContext();
 	RelationalConverter converter = new BasicRelationalConverter(context);
-
 	DbAction.WithEntity<?> rootInsert = new DbAction.InsertRoot<>(entity);
 
 	@Test // DATAJDBC-291
 	public void singleRoot() {
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 
 		aggregateChange.executeWith(new IdSettingInterpreter(), context, converter);
@@ -81,8 +81,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = entity.withSingle(content);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(createInsert("single", content, null));
 
@@ -90,7 +89,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.single.id).isEqualTo(2);
@@ -102,8 +101,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = entity.withContentList(asList(content, content2));
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(createInsert("contentList", content, 0));
 		aggregateChange.addAction(createInsert("contentList", content2, 1));
@@ -112,7 +110,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.contentList).extracting(c -> c.id).containsExactly(2, 3);
@@ -124,8 +122,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = entity.withContentMap(createContentMap("a", content, "b", content2));
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(createInsert("contentMap", content, "a"));
 		aggregateChange.addAction(createInsert("contentMap", content2, "b"));
@@ -147,8 +144,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> parentInsert = createInsert("single", content, null);
 		DbAction.Insert<?> insert = createDeepInsert("single", tag1, null, parentInsert);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 		aggregateChange.addAction(insert);
@@ -172,8 +168,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("tagList", tag1, 0, parentInsert);
 		DbAction.Insert<?> insert2 = createDeepInsert("tagList", tag2, 1, parentInsert);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 		aggregateChange.addAction(insert1);
@@ -183,7 +178,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.single.id).isEqualTo(2);
@@ -201,8 +196,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("tagSet", tag1, null, parentInsert);
 		DbAction.Insert<?> insert2 = createDeepInsert("tagSet", tag2, null, parentInsert);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 		aggregateChange.addAction(insert1);
@@ -212,7 +206,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.contentSet) //
@@ -237,8 +231,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("single", tag1, null, parentInsert1);
 		DbAction.Insert<?> insert2 = createDeepInsert("single", tag2, null, parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -249,7 +242,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.contentList) //
@@ -271,8 +264,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> insert2 = createDeepInsert("tagList", tag2, 0, parentInsert2);
 		DbAction.Insert<?> insert3 = createDeepInsert("tagList", tag3, 1, parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -284,7 +276,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.contentList) //
@@ -309,8 +301,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> insert2 = createDeepInsert("tagMap", tag2, "222", parentInsert2);
 		DbAction.Insert<?> insert3 = createDeepInsert("tagMap", tag3, "333", parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -322,7 +313,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.contentMap.entrySet()) //
@@ -351,8 +342,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("single", tag1, null, parentInsert1);
 		DbAction.Insert<?> insert2 = createDeepInsert("single", tag2, null, parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -363,7 +353,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		entity = aggregateChange.getEntity();
 
-		SoftAssertions.assertSoftly(softly -> {
+		assertSoftly(softly -> {
 
 			softly.assertThat(entity.rootId).isEqualTo(1);
 			softly.assertThat(entity.contentNoIdList) //
@@ -380,8 +370,7 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 		DbAction.Insert<?> parentInsert = createInsert("embedded.single", tag1, null);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 
@@ -441,11 +430,10 @@ public class AggregateChangeIdGenerationImmutableUnitTests {
 
 	PersistentPropertyPath<RelationalPersistentProperty> toPath(DummyEntity root, Object pathValue) {
 		// DefaultPersistentPropertyPath is package-public
-		return new WritingContext(context, entity,
+		return new WritingContext(context, entity, AggregateChange.forSave(root)).insert().stream()
-				new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class, root)).insert().stream()
+				.filter(a -> a instanceof DbAction.Insert).map(DbAction.Insert.class::cast)
-						.filter(a -> a instanceof DbAction.Insert).map(DbAction.Insert.class::cast)
+				.filter(a -> a.getEntity() == pathValue).map(DbAction.Insert::getPropertyPath).findFirst()
-						.filter(a -> a.getEntity() == pathValue).map(DbAction.Insert::getPropertyPath).findFirst()
+				.orElseThrow(() -> new IllegalArgumentException("No matching path found for " + pathValue));
-						.orElseThrow(() -> new IllegalArgumentException("No matching path found for " + pathValue));
 	}
 
 	@Value

spring-data-relational/src/test/java/org/springframework/data/relational/core/conversion/AggregateChangeIdGenerationUnitTests.java

@@ -37,7 +37,7 @@ import org.springframework.lang.Nullable;
  * Unit tests for the {@link AggregateChange}.
  *
  * @author Jens Schauder
- * Myeonghyeon-Lee
+ * @author Myeonghyeon-Lee
  */
 public class AggregateChangeIdGenerationUnitTests {
 
@@ -50,14 +50,12 @@ public class AggregateChangeIdGenerationUnitTests {
 
 	RelationalMappingContext context = new RelationalMappingContext();
 	RelationalConverter converter = new BasicRelationalConverter(context);
-
 	DbAction.WithEntity<?> rootInsert = new DbAction.InsertRoot<>(entity);
 
 	@Test // DATAJDBC-291
 	public void singleRoot() {
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 
 		aggregateChange.executeWith(new IdSettingInterpreter(), context, converter);
@@ -70,8 +68,7 @@ public class AggregateChangeIdGenerationUnitTests {
 
 		entity.single = content;
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(createInsert("single", content, null));
 
@@ -90,8 +87,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		entity.contentList.add(content);
 		entity.contentList.add(content2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(createInsert("contentList", content, 0));
 		aggregateChange.addAction(createInsert("contentList", content2, 1));
@@ -111,8 +107,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		entity.contentMap.put("a", content);
 		entity.contentMap.put("b", content2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(createInsert("contentMap", content, "a"));
 		aggregateChange.addAction(createInsert("contentMap", content2, "b"));
@@ -132,8 +127,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		DbAction.Insert<?> parentInsert = createInsert("single", content, null);
 		DbAction.Insert<?> insert = createDeepInsert("single", tag1, null, parentInsert);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 		aggregateChange.addAction(insert);
@@ -156,8 +150,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("tagList", tag1, 0, parentInsert);
 		DbAction.Insert<?> insert2 = createDeepInsert("tagList", tag2, 1, parentInsert);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 		aggregateChange.addAction(insert1);
@@ -184,8 +177,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("tagSet", tag1, null, parentInsert);
 		DbAction.Insert<?> insert2 = createDeepInsert("tagSet", tag2, null, parentInsert);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert);
 		aggregateChange.addAction(insert1);
@@ -219,8 +211,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		DbAction.Insert<?> insert1 = createDeepInsert("single", tag1, null, parentInsert1);
 		DbAction.Insert<?> insert2 = createDeepInsert("single", tag2, null, parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -253,8 +244,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		DbAction.Insert<?> insert2 = createDeepInsert("tagList", tag2, 0, parentInsert2);
 		DbAction.Insert<?> insert3 = createDeepInsert("tagList", tag3, 1, parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -292,8 +282,7 @@ public class AggregateChangeIdGenerationUnitTests {
 		DbAction.Insert<?> insert2 = createDeepInsert("tagMap", tag2, "222", parentInsert2);
 		DbAction.Insert<?> insert3 = createDeepInsert("tagMap", tag3, "333", parentInsert2);
 
-		AggregateChange<DummyEntity> aggregateChange = new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class,
+		AggregateChange<DummyEntity> aggregateChange = AggregateChange.forSave(entity);
-				entity);
 		aggregateChange.addAction(rootInsert);
 		aggregateChange.addAction(parentInsert1);
 		aggregateChange.addAction(parentInsert2);
@@ -348,11 +337,10 @@ public class AggregateChangeIdGenerationUnitTests {
 
 	PersistentPropertyPath<RelationalPersistentProperty> toPath(DummyEntity root, Object pathValue) {
 		// DefaultPersistentPropertyPath is package-public
-		return new WritingContext(context, entity,
+		return new WritingContext(context, entity, AggregateChange.forSave(root)).insert().stream()
-				new AggregateChange<>(AggregateChange.Kind.SAVE, DummyEntity.class, root)).insert().stream()
+				.filter(a -> a instanceof DbAction.Insert).map(DbAction.Insert.class::cast)
-						.filter(a -> a instanceof DbAction.Insert).map(DbAction.Insert.class::cast)
+				.filter(a -> a.getEntity() == pathValue).map(DbAction.Insert::getPropertyPath).findFirst()
-						.filter(a -> a.getEntity() == pathValue).map(DbAction.Insert::getPropertyPath).findFirst()
+				.orElseThrow(() -> new IllegalArgumentException("No matching path found"));
-						.orElseThrow(() -> new IllegalArgumentException("No matching path found"));
 	}
 
 	private static class DummyEntity {