DATAJDBC-393 - EntityCallback support.

An `EntityCallback` works very similar to an `ApplicationEvent` but returns a potentially changed instance.
The returned instance will be used in further processing which enables proper event handling for immutable classes.

Auditing was changed to use a callback making it work also with immutable objects.

Original pull request: #161.

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

@@ -16,10 +16,15 @@
 package org.springframework.data.jdbc.core;
 
 import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
 import org.springframework.data.mapping.IdentifierAccessor;
+import org.springframework.data.mapping.callback.EntityCallback;
+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;
@@ -30,12 +35,7 @@ import org.springframework.data.relational.core.conversion.RelationalEntityUpdat
 import org.springframework.data.relational.core.conversion.RelationalEntityWriter;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
 import org.springframework.data.relational.core.mapping.RelationalPersistentEntity;
-import org.springframework.data.relational.core.mapping.event.AfterDeleteEvent;
-import org.springframework.data.relational.core.mapping.event.AfterLoadEvent;
-import org.springframework.data.relational.core.mapping.event.AfterSaveEvent;
-import org.springframework.data.relational.core.mapping.event.BeforeDeleteEvent;
-import org.springframework.data.relational.core.mapping.event.BeforeSaveEvent;
-import org.springframework.data.relational.core.mapping.event.Identifier;
+import org.springframework.data.relational.core.mapping.event.*;
 import org.springframework.data.relational.core.mapping.event.Identifier.Specified;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -62,6 +62,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 
 	private final DataAccessStrategy accessStrategy;
 
+	private EntityCallbacks entityCallbacks = NoopEntityCallback.INSTANCE;
+
 	/**
 	 * Creates a new {@link JdbcAggregateTemplate} given {@link ApplicationEventPublisher},
 	 * {@link RelationalMappingContext} and {@link DataAccessStrategy}.
@@ -90,6 +92,13 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		this.interpreter = new DefaultJdbcInterpreter(context, accessStrategy);
 	}
 
+	public void setEntityCallbacks(EntityCallbacks entityCallbacks) {
+
+		Assert.notNull(entityCallbacks, "Callbacks must not be null.");
+
+		this.entityCallbacks = entityCallbacks;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.jdbc.core.JdbcAggregateOperations#save(java.lang.Object)
@@ -100,11 +109,11 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		Assert.notNull(instance, "Aggregate instance must not be null!");
 
 		RelationalPersistentEntity<?> persistentEntity = context.getRequiredPersistentEntity(instance.getClass());
-		IdentifierAccessor identifierAccessor = persistentEntity.getIdentifierAccessor(instance);
 
-		AggregateChange<T> change = createChange(instance);
+		Function<T, AggregateChange<T>> changeCreator = persistentEntity.isNew(instance) ? this::createInsertChange
+				: this::createUpdateChange;
 
-		return store(instance, identifierAccessor, change, persistentEntity);
+		return store(instance, changeCreator, persistentEntity);
 	}
 
 	/**
@@ -120,11 +129,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		Assert.notNull(instance, "Aggregate instance must not be null!");
 
 		RelationalPersistentEntity<?> persistentEntity = context.getRequiredPersistentEntity(instance.getClass());
-		IdentifierAccessor identifierAccessor = persistentEntity.getIdentifierAccessor(instance);
-
-		AggregateChange<T> change = createInsertChange(instance);
 
-		return store(instance, identifierAccessor, change, persistentEntity);
+		return store(instance, this::createInsertChange, persistentEntity);
 	}
 
 	/**
@@ -140,11 +146,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		Assert.notNull(instance, "Aggregate instance must not be null!");
 
 		RelationalPersistentEntity<?> persistentEntity = context.getRequiredPersistentEntity(instance.getClass());
-		IdentifierAccessor identifierAccessor = persistentEntity.getIdentifierAccessor(instance);
 
-		AggregateChange<T> change = createUpdateChange(instance);
-
-		return store(instance, identifierAccessor, change, persistentEntity);
+		return store(instance, this::createUpdateChange, persistentEntity);
 	}
 
 	/*
@@ -171,7 +174,7 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 
 		T entity = accessStrategy.findById(id, domainType);
 		if (entity != null) {
-			publishAfterLoad(id, entity);
+			return triggerAfterLoad(id, entity);
 		}
 		return entity;
 	}
@@ -199,8 +202,7 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		Assert.notNull(domainType, "Domain type must not be null!");
 
 		Iterable<T> all = accessStrategy.findAll(domainType);
-		publishAfterLoad(all);
-		return all;
+		return triggerAfterLoad(all);
 	}
 
 	/*
@@ -214,8 +216,7 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		Assert.notNull(domainType, "Domain type must not be null!");
 
 		Iterable<T> allById = accessStrategy.findAllById(ids, domainType);
-		publishAfterLoad(allById);
-		return allById;
+		return triggerAfterLoad(allById);
 	}
 
 	/*
@@ -260,16 +261,20 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		change.executeWith(interpreter, context, converter);
 	}
 
-	private <T> T store(T instance, IdentifierAccessor identifierAccessor, AggregateChange<T> change,
+	private <T> T store(T aggregateRoot, Function<T, AggregateChange<T>> changeCreator,
 			RelationalPersistentEntity<?> persistentEntity) {
 
-		Assert.notNull(instance, "Aggregate instance must not be null!");
+		Assert.notNull(aggregateRoot, "Aggregate instance must not be null!");
 
-		publisher.publishEvent(new BeforeSaveEvent( //
-				Identifier.ofNullable(identifierAccessor.getIdentifier()), //
-				instance, //
-				change //
-		));
+		aggregateRoot = triggerBeforeConvert(aggregateRoot,
+				persistentEntity.getIdentifierAccessor(aggregateRoot).getIdentifier());
+
+		AggregateChange<T> change = changeCreator.apply(aggregateRoot);
+
+		aggregateRoot = triggerBeforeSave(aggregateRoot,
+				persistentEntity.getIdentifierAccessor(aggregateRoot).getIdentifier(), change);
+
+		change.setEntity(aggregateRoot);
 
 		change.executeWith(interpreter, context, converter);
 
@@ -277,31 +282,26 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 
 		Assert.notNull(identifier, "After saving the identifier must not be null!");
 
-		publisher.publishEvent(new AfterSaveEvent( //
-				Identifier.of(identifier), //
-				change.getEntity(), //
-				change //
-		));
-
-		return (T) change.getEntity();
+		return triggerAfterSave(change.getEntity(), identifier, change);
 	}
 
-	private void deleteTree(Object id, @Nullable Object entity, Class<?> domainType) {
+	private <T> void deleteTree(Object id, @Nullable T entity, Class<T> domainType) {
 
-		AggregateChange<?> change = createDeletingChange(id, entity, domainType);
+		AggregateChange<T> change = createDeletingChange(id, entity, domainType);
 
-		Specified specifiedId = Identifier.of(id);
-		Optional<Object> optionalEntity = Optional.ofNullable(entity);
-		publisher.publishEvent(new BeforeDeleteEvent(specifiedId, optionalEntity, change));
+		entity = triggerBeforeDelete(entity, id, change);
+		change.setEntity(entity);
 
 		change.executeWith(interpreter, context, converter);
 
-		publisher.publishEvent(new AfterDeleteEvent(specifiedId, optionalEntity, change));
+		triggerAfterDelete(entity, id, change);
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private <T> AggregateChange<T> createChange(T instance) {
 
+		// context.getRequiredPersistentEntity(o.getClass()).isNew(o)
+
 		AggregateChange<T> aggregateChange = new AggregateChange(Kind.SAVE, instance.getClass(), instance);
 		jdbcEntityWriter.write(instance, aggregateChange);
 		return aggregateChange;
@@ -324,9 +324,9 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })
-	private AggregateChange<?> createDeletingChange(Object id, @Nullable Object entity, Class<?> domainType) {
+	private <T> AggregateChange<T> createDeletingChange(Object id, @Nullable T entity, Class<T> domainType) {
 
-		AggregateChange<?> aggregateChange = new AggregateChange(Kind.DELETE, domainType, entity);
+		AggregateChange<T> aggregateChange = new AggregateChange(Kind.DELETE, domainType, entity);
 		jdbcEntityDeleteWriter.write(id, aggregateChange);
 		return aggregateChange;
 	}
@@ -338,18 +338,96 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 		return aggregateChange;
 	}
 
-	private <T> void publishAfterLoad(Iterable<T> all) {
+	private <T> Iterable<T> triggerAfterLoad(Iterable<T> all) {
 
-		for (T e : all) {
+		return StreamSupport.stream(all.spliterator(), false).map(e -> {
 
 			RelationalPersistentEntity<?> entity = context.getRequiredPersistentEntity(e.getClass());
 			IdentifierAccessor identifierAccessor = entity.getIdentifierAccessor(e);
 
-			publishAfterLoad(identifierAccessor.getRequiredIdentifier(), e);
-		}
+			return triggerAfterLoad(identifierAccessor.getRequiredIdentifier(), e);
+		}).collect(Collectors.toList());
 	}
 
-	private <T> void publishAfterLoad(Object id, T entity) {
+	private <T> T triggerAfterLoad(Object id, T entity) {
+
 		publisher.publishEvent(new AfterLoadEvent(Identifier.of(id), entity));
+
+		return entityCallbacks.callback(AfterLoadCallback.class, entity, Identifier.of(id));
+	}
+
+	private <T> T triggerBeforeConvert(T aggregateRoot, @Nullable Object id) {
+
+		Identifier identifier = Identifier.ofNullable(id);
+
+		return entityCallbacks.callback(BeforeConvertCallback.class, aggregateRoot, identifier);
+	}
+
+	private <T> T triggerBeforeSave(T aggregateRoot, @Nullable Object id, AggregateChange<T> change) {
+
+		Identifier identifier = Identifier.ofNullable(id);
+
+		publisher.publishEvent(new BeforeSaveEvent( //
+				identifier, //
+				aggregateRoot, //
+				change //
+		));
+
+		return entityCallbacks.callback(BeforeSaveCallback.class, aggregateRoot, identifier);
+	}
+
+	private <T> T triggerAfterSave(T aggregateRoot, Object id, AggregateChange<T> change) {
+
+		Specified identifier = Identifier.of(id);
+
+		publisher.publishEvent(new AfterSaveEvent( //
+				identifier, //
+				aggregateRoot, //
+				change //
+		));
+
+		return entityCallbacks.callback(AfterSaveCallback.class, aggregateRoot, identifier);
+	}
+
+	@Nullable
+	private <T> void triggerAfterDelete(@Nullable T aggregateRoot, Object id, AggregateChange<?> change) {
+
+		Specified identifier = Identifier.of(id);
+
+		publisher.publishEvent(new AfterDeleteEvent(identifier, Optional.ofNullable(aggregateRoot), change));
+
+		if (aggregateRoot != null) {
+			entityCallbacks.callback(AfterDeleteCallback.class, aggregateRoot, identifier);
+		}
+	}
+
+	@Nullable
+	private <T> T triggerBeforeDelete(@Nullable T aggregateRoot, Object id, AggregateChange<?> change) {
+
+		Specified identifier = Identifier.of(id);
+
+		publisher.publishEvent(new BeforeDeleteEvent(identifier, Optional.ofNullable(aggregateRoot), change));
+
+		if (aggregateRoot != null) {
+			return entityCallbacks.callback(BeforeDeleteCallback.class, aggregateRoot, identifier);
+		}
+		return aggregateRoot;
+	}
+
+	/**
+	 * An {@link EntityCallbacks} implementation doing nothing.
+	 */
+	private enum NoopEntityCallback implements EntityCallbacks {
+
+		INSTANCE {
+
+			@Override
+			public void addEntityCallback(EntityCallback<?> callback) {}
+
+			@Override
+			public <T> T callback(Class<? extends EntityCallback> callbackType, T entity, Object... args) {
+				return entity;
+			}
+		}
 	}
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/config/JdbcAuditingRegistrar.java

@@ -24,6 +24,7 @@ import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
 import org.springframework.data.auditing.IsNewAwareAuditingHandler;
 import org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport;
 import org.springframework.data.auditing.config.AuditingConfiguration;
+import org.springframework.data.relational.domain.support.RelationalAuditingCallback;
 import org.springframework.data.relational.domain.support.RelationalAuditingEventListener;
 import org.springframework.util.Assert;
 
@@ -86,7 +87,7 @@ class JdbcAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 	protected void registerAuditListenerBeanDefinition(BeanDefinition auditingHandlerDefinition,
 			BeanDefinitionRegistry registry) {
 
-		Class<?> listenerClass = RelationalAuditingEventListener.class;
+		Class<?> listenerClass = RelationalAuditingCallback.class;
 		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(listenerClass) //
 				.addConstructorArgReference(AUDITING_HANDLER_BEAN_NAME);
 

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/support/JdbcRepositoryFactory.java

@@ -23,6 +23,7 @@ import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
 import org.springframework.data.jdbc.core.convert.JdbcConverter;
 import org.springframework.data.jdbc.repository.QueryMappingConfiguration;
 import org.springframework.data.jdbc.repository.RowMapperMap;
+import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
 import org.springframework.data.relational.core.mapping.RelationalPersistentEntity;
 import org.springframework.data.repository.core.EntityInformation;
@@ -53,6 +54,7 @@ public class JdbcRepositoryFactory extends RepositoryFactorySupport {
 	private final NamedParameterJdbcOperations operations;
 
 	private QueryMappingConfiguration queryMappingConfiguration = QueryMappingConfiguration.EMPTY;
+	private EntityCallbacks entityCallbacks;
 
 	/**
 	 * Creates a new {@link JdbcRepositoryFactory} for the given {@link DataAccessStrategy},
@@ -117,7 +119,13 @@ public class JdbcRepositoryFactory extends RepositoryFactorySupport {
 
 		JdbcAggregateTemplate template = new JdbcAggregateTemplate(publisher, context, converter, accessStrategy);
 
-		return new SimpleJdbcRepository<>(template, context.getPersistentEntity(repositoryInformation.getDomainType()));
+		SimpleJdbcRepository<?, Object> repository = new SimpleJdbcRepository<>(template, context.getPersistentEntity(repositoryInformation.getDomainType()));
+
+		if (entityCallbacks != null) {
+			template.setEntityCallbacks(entityCallbacks);
+		}
+
+		return repository;
 	}
 
 	/*
@@ -147,4 +155,9 @@ public class JdbcRepositoryFactory extends RepositoryFactorySupport {
 
 		throw new IllegalArgumentException(String.format("Unsupported query lookup strategy %s!", key));
 	}
+
+	public void setEntityCallbacks(EntityCallbacks entityCallbacks) {
+
+		this.entityCallbacks = entityCallbacks;
+	}
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/support/JdbcRepositoryFactoryBean.java

@@ -27,6 +27,7 @@ import org.springframework.data.jdbc.core.convert.JdbcConverter;
 import org.springframework.data.jdbc.core.convert.SqlGeneratorSource;
 import org.springframework.data.jdbc.repository.QueryMappingConfiguration;
 import org.springframework.data.jdbc.repository.RowMapperMap;
+import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.support.RepositoryFactorySupport;
@@ -54,6 +55,7 @@ public class JdbcRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extend
 	private DataAccessStrategy dataAccessStrategy;
 	private QueryMappingConfiguration queryMappingConfiguration = QueryMappingConfiguration.EMPTY;
 	private NamedParameterJdbcOperations operations;
+	private EntityCallbacks entityCallbacks;
 
 	/**
 	 * Creates a new {@link JdbcRepositoryFactoryBean} for the given repository interface.
@@ -85,6 +87,7 @@ public class JdbcRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extend
 		JdbcRepositoryFactory jdbcRepositoryFactory = new JdbcRepositoryFactory(dataAccessStrategy, mappingContext,
 				converter, publisher, operations);
 		jdbcRepositoryFactory.setQueryMappingConfiguration(queryMappingConfiguration);
+		jdbcRepositoryFactory.setEntityCallbacks(entityCallbacks);
 
 		return jdbcRepositoryFactory;
 	}
@@ -151,10 +154,16 @@ public class JdbcRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extend
 		Assert.state(this.converter != null, "RelationalConverter is required and must not be null!");
 
 		if (this.operations == null) {
+
+			Assert.state(beanFactory != null, "If no JdbcOperations are set a BeanFactory must be available.");
+
 			this.operations = beanFactory.getBean(NamedParameterJdbcOperations.class);
 		}
 
 		if (this.dataAccessStrategy == null) {
+
+			Assert.state(beanFactory != null, "If no DataAccessStrategy is set a BeanFactory must be available.");
+
 			this.dataAccessStrategy = this.beanFactory.getBeanProvider(DataAccessStrategy.class) //
 					.getIfAvailable(() -> {
 
@@ -168,6 +177,10 @@ public class JdbcRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extend
 			this.queryMappingConfiguration = QueryMappingConfiguration.EMPTY;
 		}
 
+		if (beanFactory != null) {
+			entityCallbacks = EntityCallbacks.create(beanFactory);
+		}
+
 		super.afterPropertiesSet();
 	}
 }

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/JdbcAggregateTemplateIntegrationTests.java

@@ -44,6 +44,7 @@ import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
 import org.springframework.data.jdbc.testing.DatabaseProfileValueSource;
 import org.springframework.data.jdbc.testing.TestConfiguration;
+import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.conversion.RelationalConverter;
 import org.springframework.data.relational.core.mapping.Column;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
@@ -71,6 +72,7 @@ public class JdbcAggregateTemplateIntegrationTests {
 
 	@ClassRule public static final SpringClassRule classRule = new SpringClassRule();
 	@Rule public SpringMethodRule methodRule = new SpringMethodRule();
+
 	@Autowired JdbcAggregateOperations template;
 	@Autowired NamedParameterJdbcOperations jdbcTemplate;
 	LegoSet legoSet = createLegoSet();
@@ -728,22 +730,6 @@ public class JdbcAggregateTemplateIntegrationTests {
 		private String content;
 	}
 
-	@Configuration
-	@Import(TestConfiguration.class)
-	static class Config {
-
-		@Bean
-		Class<?> testClass() {
-			return JdbcAggregateTemplateIntegrationTests.class;
-		}
-
-		@Bean
-		JdbcAggregateOperations operations(ApplicationEventPublisher publisher, RelationalMappingContext context,
-				DataAccessStrategy dataAccessStrategy, RelationalConverter converter) {
-			return new JdbcAggregateTemplate(publisher, context, converter, dataAccessStrategy);
-		}
-	}
-
 	/**
 	 * One may think of ChainN as a chain with N further elements
 	 */
@@ -869,4 +855,21 @@ public class JdbcAggregateTemplateIntegrationTests {
 		String fourValue;
 		Map<String, NoIdMapChain3> chain3 = new HashMap<>();
 	}
+
+
+	@Configuration
+	@Import(TestConfiguration.class)
+	static class Config {
+
+		@Bean
+		Class<?> testClass() {
+			return JdbcAggregateTemplateIntegrationTests.class;
+		}
+
+		@Bean
+		JdbcAggregateOperations operations(ApplicationEventPublisher publisher, RelationalMappingContext context,
+										   DataAccessStrategy dataAccessStrategy, RelationalConverter converter) {
+			return new JdbcAggregateTemplate(publisher, context, converter, dataAccessStrategy);
+		}
+	}
 }

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/JdbcAggregateTemplateUnitTests.java

@@ -15,13 +15,14 @@
  */
 package org.springframework.data.jdbc.core;
 
+import static java.util.Arrays.*;
 import static java.util.Collections.*;
 import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
 
+import lombok.AllArgsConstructor;
 import lombok.Data;
 
-import javax.sql.DataSource;
-
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -31,15 +32,19 @@ import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.convert.BasicJdbcConverter;
 import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
-import org.springframework.data.jdbc.core.convert.DefaultDataAccessStrategy;
 import org.springframework.data.jdbc.core.convert.JdbcConverter;
 import org.springframework.data.jdbc.core.convert.RelationResolver;
-import org.springframework.data.jdbc.core.convert.SqlGeneratorSource;
+import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.mapping.Column;
 import org.springframework.data.relational.core.mapping.NamingStrategy;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
-import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
-import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
+import org.springframework.data.relational.core.mapping.event.AfterDeleteCallback;
+import org.springframework.data.relational.core.mapping.event.AfterLoadCallback;
+import org.springframework.data.relational.core.mapping.event.AfterSaveCallback;
+import org.springframework.data.relational.core.mapping.event.BeforeConvertCallback;
+import org.springframework.data.relational.core.mapping.event.BeforeDeleteCallback;
+import org.springframework.data.relational.core.mapping.event.BeforeSaveCallback;
+import org.springframework.data.relational.core.mapping.event.Identifier;
 
 /**
  * @author Christoph Strobl
@@ -49,19 +54,19 @@ public class JdbcAggregateTemplateUnitTests {
 
 	JdbcAggregateOperations template;
 
+	@Mock DataAccessStrategy dataAccessStrategy;
 	@Mock ApplicationEventPublisher eventPublisher;
 	@Mock RelationResolver relationResolver;
-	@Mock DataSource dataSource;
+	@Mock EntityCallbacks callbacks;
 
 	@Before
 	public void setUp() {
 
 		RelationalMappingContext mappingContext = new RelationalMappingContext(NamingStrategy.INSTANCE);
 		JdbcConverter converter = new BasicJdbcConverter(mappingContext, relationResolver);
-		NamedParameterJdbcOperations namedParameterJdbcOperations = new NamedParameterJdbcTemplate(dataSource);
-		DataAccessStrategy dataAccessStrategy = new DefaultDataAccessStrategy(new SqlGeneratorSource(mappingContext),
-				mappingContext, converter, namedParameterJdbcOperations);
+
 		template = new JdbcAggregateTemplate(eventPublisher, mappingContext, converter, dataAccessStrategy);
+		((JdbcAggregateTemplate) template).setEntityCallbacks(callbacks);
 	}
 
 	@Test // DATAJDBC-378
@@ -81,7 +86,61 @@ public class JdbcAggregateTemplateUnitTests {
 		assertThat(template.findAllById(emptyList(), SampleEntity.class)).isEmpty();
 	}
 
+	@Test // DATAJDBC-393
+	public void callbackOnSave() {
+
+		SampleEntity first = new SampleEntity(null, "Alfred");
+		SampleEntity second = new SampleEntity(23L, "Alfred E.");
+		SampleEntity third = new SampleEntity(23L, "Neumann");
+
+		when(callbacks.callback(any(Class.class), any(), any())).thenReturn(second, third);
+
+		SampleEntity last = template.save(first);
+
+		verify(callbacks).callback(BeforeConvertCallback.class, first, Identifier.ofNullable(null));
+		verify(callbacks).callback(BeforeSaveCallback.class, second, Identifier.ofNullable(23L));
+		verify(callbacks).callback(AfterSaveCallback.class, third, Identifier.of(23L));
+		assertThat(last).isEqualTo(third);
+	}
+
+	@Test // DATAJDBC-393
+	public void callbackOnDelete() {
+
+		SampleEntity first = new SampleEntity(23L, "Alfred");
+		SampleEntity second = new SampleEntity(23L, "Alfred E.");
+
+		when(callbacks.callback(any(Class.class), any(), any())).thenReturn(second);
+
+		template.delete(first, SampleEntity.class);
+
+		verify(callbacks).callback(BeforeDeleteCallback.class, first, Identifier.of(23L));
+		verify(callbacks).callback(AfterDeleteCallback.class, second, Identifier.of(23L));
+	}
+
+	@Test // DATAJDBC-393
+	public void callbackOnLoad() {
+
+		SampleEntity alfred1 = new SampleEntity(23L, "Alfred");
+		SampleEntity alfred2 = new SampleEntity(23L, "Alfred E.");
+
+		SampleEntity neumann1 = new SampleEntity(42L, "Neumann");
+		SampleEntity neumann2 = new SampleEntity(42L, "Alfred E. Neumann");
+
+		when(dataAccessStrategy.findAll(SampleEntity.class)).thenReturn(asList(alfred1, neumann1));
+
+		when(callbacks.callback(any(Class.class), eq(alfred1), any())).thenReturn(alfred2);
+		when(callbacks.callback(any(Class.class), eq(neumann1), any())).thenReturn(neumann2);
+
+		Iterable<SampleEntity> all = template.findAll(SampleEntity.class);
+
+		verify(callbacks).callback(AfterLoadCallback.class, alfred1, Identifier.of(23L));
+		verify(callbacks).callback(AfterLoadCallback.class, neumann1, Identifier.of(42L));
+
+		assertThat(all).containsExactly(alfred2, neumann2);
+	}
+
 	@Data
+	@AllArgsConstructor
 	private static class SampleEntity {
 
 		@Column("id1") @Id private Long id;

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

@@ -20,6 +20,9 @@ import static org.assertj.core.api.Assertions.*;
 import lombok.Data;
 import lombok.Value;
 import lombok.experimental.FieldDefaults;
+import lombok.experimental.Wither;
+
+import java.util.concurrent.atomic.AtomicLong;
 
 import org.junit.ClassRule;
 import org.junit.Rule;
@@ -34,6 +37,7 @@ import org.springframework.data.jdbc.repository.config.EnableJdbcRepositories;
 import org.springframework.data.jdbc.repository.support.JdbcRepositoryFactory;
 import org.springframework.data.jdbc.repository.support.SimpleJdbcRepository;
 import org.springframework.data.relational.core.mapping.NamingStrategy;
+import org.springframework.data.relational.core.mapping.event.BeforeConvertCallback;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
 import org.springframework.test.context.ContextConfiguration;
@@ -67,6 +71,7 @@ public class JdbcRepositoryIdGenerationIntegrationTests {
 	@Autowired NamedParameterJdbcTemplate template;
 	@Autowired ReadOnlyIdEntityRepository readOnlyIdrepository;
 	@Autowired PrimitiveIdEntityRepository primitiveIdRepository;
+	@Autowired ImmutableWithManualIdEntityRepository immutableWithManualIdEntityRepository;
 
 	@Test // DATAJDBC-98
 	public void idWithoutSetterGetsSet() {
@@ -99,10 +104,23 @@ public class JdbcRepositoryIdGenerationIntegrationTests {
 		});
 	}
 
+	@Test // DATAJDBC-393
+	public void manuallyGeneratedId() {
+
+		ImmutableWithManualIdEntity entity = new ImmutableWithManualIdEntity(null, "immutable");
+		ImmutableWithManualIdEntity saved = immutableWithManualIdEntityRepository.save(entity);
+
+		assertThat(saved.getId()).isNotNull();
+
+		assertThat(immutableWithManualIdEntityRepository.findAll()).hasSize(1);
+	}
+
 	private interface PrimitiveIdEntityRepository extends CrudRepository<PrimitiveIdEntity, Long> {}
 
 	public interface ReadOnlyIdEntityRepository extends CrudRepository<ReadOnlyIdEntity, Long> {}
 
+	private interface ImmutableWithManualIdEntityRepository extends CrudRepository<ImmutableWithManualIdEntity, Long> {}
+
 	@Value
 	@FieldDefaults(makeFinal = false)
 	static class ReadOnlyIdEntity {
@@ -118,11 +136,20 @@ public class JdbcRepositoryIdGenerationIntegrationTests {
 		String name;
 	}
 
+	@Value
+	@Wither
+	static class ImmutableWithManualIdEntity {
+		@Id Long id;
+		String name;
+	}
+
 	@Configuration
 	@ComponentScan("org.springframework.data.jdbc.testing")
 	@EnableJdbcRepositories(considerNestedRepositories = true)
 	static class TestConfiguration {
 
+		AtomicLong lastId = new AtomicLong(0);
+
 		@Bean
 		Class<?> testClass() {
 			return JdbcRepositoryIdGenerationIntegrationTests.class;
@@ -134,12 +161,19 @@ public class JdbcRepositoryIdGenerationIntegrationTests {
 		 */
 		@Bean
 		NamingStrategy namingStrategy() {
+
 			return new NamingStrategy() {
+
 				@Override
 				public String getTableName(Class<?> type) {
 					return type.getSimpleName().toUpperCase();
 				}
 			};
 		}
+
+		@Bean
+		BeforeConvertCallback<ImmutableWithManualIdEntity> idGenerator() {
+			return (e, __) -> e.withId(lastId.incrementAndGet());
+		}
 	}
 }

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

@@ -42,7 +42,9 @@ import org.springframework.data.annotation.LastModifiedDate;
 import org.springframework.data.auditing.DateTimeProvider;
 import org.springframework.data.domain.AuditorAware;
 import org.springframework.data.relational.core.mapping.NamingStrategy;
+import org.springframework.data.relational.core.mapping.event.BeforeConvertCallback;
 import org.springframework.data.relational.core.mapping.event.BeforeSaveEvent;
+import org.springframework.data.relational.core.mapping.event.Identifier;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.stereotype.Component;
 import org.springframework.test.context.ActiveProfiles;
@@ -186,7 +188,9 @@ public class EnableJdbcAuditingHsqlIntegrationTests {
 				AuditingAnnotatedDummyEntityRepository.class, //
 				TestConfiguration.class, //
 				AuditingConfiguration.class, //
-				OrderAssertingEventListener.class) //
+				OrderAssertingEventListener.class, //
+				OrderAssertingCallback.class //
+		) //
 						.accept(repository -> {
 
 							AuditingAnnotatedDummyEntity entity = repository.save(new AuditingAnnotatedDummyEntity());
@@ -331,4 +335,21 @@ public class EnableJdbcAuditingHsqlIntegrationTests {
 			assertThat(((AuditingAnnotatedDummyEntity) entity).createdDate).isNotNull();
 		}
 	}
+
+	/**
+	 * An event listener asserting that it is running after {@link AuditingConfiguration#auditorAware()} was invoked and
+	 * set the auditing data.
+	 */
+	@Component
+	static class OrderAssertingCallback implements BeforeConvertCallback {
+
+		@Override
+		public Object onBeforeConvert(Object entity, Identifier id) {
+
+			assertThat(entity).isInstanceOf(AuditingAnnotatedDummyEntity.class);
+			assertThat(((AuditingAnnotatedDummyEntity) entity).createdDate).isNotNull();
+
+			return entity;
+		}
+	}
 }

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

@@ -23,10 +23,10 @@ import java.util.function.Supplier;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Answers;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnitRunner;
 import org.mockito.stubbing.Answer;
-
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.ObjectProvider;
@@ -35,7 +35,6 @@ import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.convert.BasicJdbcConverter;
 import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
 import org.springframework.data.jdbc.core.convert.DefaultDataAccessStrategy;
-import org.springframework.data.jdbc.core.convert.JdbcTypeFactory;
 import org.springframework.data.jdbc.core.mapping.JdbcMappingContext;
 import org.springframework.data.jdbc.repository.QueryMappingConfiguration;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
@@ -60,7 +59,7 @@ public class JdbcRepositoryFactoryBeanUnitTests {
 
 	@Mock DataAccessStrategy dataAccessStrategy;
 	@Mock ApplicationEventPublisher publisher;
-	@Mock ListableBeanFactory beanFactory;
+	@Mock(answer = Answers.RETURNS_DEEP_STUBS) ListableBeanFactory beanFactory;
 
 	RelationalMappingContext mappingContext;
 

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/testing/TestConfiguration.java

@@ -20,6 +20,8 @@ import java.util.Optional;
 import javax.sql.DataSource;
 
 import org.apache.ibatis.session.SqlSessionFactory;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.context.ApplicationEventPublisher;
@@ -38,6 +40,7 @@ import org.springframework.data.jdbc.core.convert.RelationResolver;
 import org.springframework.data.jdbc.core.convert.SqlGeneratorSource;
 import org.springframework.data.jdbc.core.mapping.JdbcMappingContext;
 import org.springframework.data.jdbc.repository.support.JdbcRepositoryFactory;
+import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.mapping.NamingStrategy;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;

spring-data-jdbc/src/test/resources/logback.xml

@@ -8,7 +8,7 @@
 	</appender>
 
 	<!--<logger name="org.springframework.data" level="info" />-->
-	<!--<logger name="org.springframework.jdbc.core" level="trace" />-->
+	<logger name="org.springframework.jdbc.core" level="trace" />
 	<!--<logger name="org.springframework.data.jdbc.mybatis.DummyEntityMapper" level="trace" />-->
 
 	<root level="warn">

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIdGenerationIntegrationTests-hsql.sql

@@ -1,4 +1,5 @@
 -- noinspection SqlNoDataSourceInspectionForFile
 
-CREATE TABLE ReadOnlyIdEntity (ID BIGINT GENERATED BY DEFAULT AS IDENTITY(START WITH 1) PRIMARY KEY, NAME VARCHAR(100))
-CREATE TABLE PrimitiveIdEntity (ID BIGINT GENERATED BY DEFAULT AS IDENTITY(START WITH 1) PRIMARY KEY, NAME VARCHAR(100))
+CREATE TABLE ReadOnlyIdEntity (ID BIGINT GENERATED BY DEFAULT AS IDENTITY(START WITH 1) PRIMARY KEY, NAME VARCHAR(100));
+CREATE TABLE PrimitiveIdEntity (ID BIGINT GENERATED BY DEFAULT AS IDENTITY(START WITH 1) PRIMARY KEY, NAME VARCHAR(100));
+CREATE TABLE ImmutableWithManualIdentity (ID BIGINT PRIMARY KEY, NAME VARCHAR(100));

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

@@ -99,6 +99,11 @@ public class AggregateChange<T> {
 		}
 	}
 
+
+	public void setEntity(@Nullable T aggregateRoot) {
+		entity = aggregateRoot;
+	}
+
 	@SuppressWarnings("unchecked")
 	private static <T> void setIdInElementOfSet(RelationalConverter converter, DbAction.WithDependingOn<?> action,
 			Object generatedId, Set<T> set) {

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/AfterDeleteCallback.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2019 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.relational.core.mapping.event;
+
+import org.springframework.data.mapping.callback.EntityCallback;
+import org.springframework.lang.Nullable;
+
+/**
+ * An {@link EntityCallback} that gets called after an aggregate got deleted. This callback gets only invoked if
+ * the method deleting the aggregate received an instance of that aggregate as an argument. Methods deleting entities by id or
+ * without any parameter don't invoke this callback.
+ * 
+ * @since 1.1
+ * @author Jens Schauder
+ */
+@FunctionalInterface
+public interface AfterDeleteCallback<T> extends EntityCallback<T> {
+
+	T onAfterDelete(@Nullable T aggregate, Identifier id);
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/AfterDeleteEvent.java

@@ -36,7 +36,7 @@ public class AfterDeleteEvent extends RelationalEventWithId {
 	 * @param change the {@link AggregateChange} encoding the actions that were performed on the database as part of the
 	 *          delete operation.
 	 */
-	public AfterDeleteEvent(Specified id, Optional<Object> instance, AggregateChange change) {
+	public AfterDeleteEvent(Specified id, Optional<?> instance, AggregateChange change) {
 		super(id, instance, change);
 	}
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/AfterLoadCallback.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2019 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.relational.core.mapping.event;
+
+import org.springframework.data.mapping.callback.EntityCallback;
+
+/**
+ * An {@link EntityCallback} that gets invoked after an aggregate gets loaded from the database.
+ * 
+ * @since 1.1
+ * @author Jens Schauder
+ */
+@FunctionalInterface
+public interface AfterLoadCallback<T> extends EntityCallback<T> {
+	T onAfterLoad(T aggregate, Identifier.Specified id);
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/AfterSaveCallback.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2019 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.relational.core.mapping.event;
+
+import org.springframework.data.mapping.callback.EntityCallback;
+
+/**
+ * An {@link EntityCallback} that gets invoked after an aggregate was saved.
+ * 
+ * @since 1.1
+ * @author Jens Schauder
+ */
+@FunctionalInterface
+public interface AfterSaveCallback<T> extends EntityCallback<T> {
+	T onAfterSave(T aggregate, Identifier.Specified id);
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/BeforeConvertCallback.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2019 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.relational.core.mapping.event;
+
+import org.springframework.data.mapping.callback.EntityCallback;
+
+/**
+ * An {@link EntityCallback} that gets invoked before the aggregate gets converted into a database change. The decision
+ * if the change will be an insert or update will be made before this callback gets called.
+ * 
+ * @since 1.1
+ * @author Jens Schauder
+ */
+@FunctionalInterface
+public interface BeforeConvertCallback<T> extends EntityCallback<T> {
+	T onBeforeConvert(T aggregate, Identifier id);
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/BeforeConvertEvent.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2017-2019 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.relational.core.mapping.event;
+
+import org.springframework.data.relational.core.conversion.AggregateChange;
+import org.springframework.data.relational.core.mapping.event.Identifier.Specified;
+
+/**
+ * Gets published before an aggregate gets converted into a database change.
+ *
+ * @since 1.1
+ * @author Jens Schauder
+ */
+public class BeforeConvertEvent extends RelationalEventWithIdAndEntity {
+
+	private static final long serialVersionUID = 3980149746683849019L;
+
+	/**
+	 * @param id identifier of the saved entity.
+	 * @param instance the saved entity.
+	 * @param change the {@link AggregateChange} encoding the actions performed on the database as part of the delete.
+	 */
+	public BeforeConvertEvent(Specified id, Object instance, AggregateChange change) {
+		super(id, instance, change);
+	}
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/BeforeDeleteCallback.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2019 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.relational.core.mapping.event;
+
+import org.springframework.data.mapping.callback.EntityCallback;
+
+/**
+ * An {@link EntityCallback} that gets invoked before an entity gets deleted.This callback gets only invoked if * the
+ * method deleting the aggregate received an instance of that aggregate as an argument. Methods deleting entities by id
+ * or * without any parameter don't invoke this callback.
+ *
+ * @since 1.1
+ * @author Jens Schauder
+ */
+@FunctionalInterface
+public interface BeforeDeleteCallback<T> extends EntityCallback<T> {
+
+	T onBeforeDelete(T aggregate, Identifier id);
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/BeforeDeleteEvent.java

@@ -35,7 +35,7 @@ public class BeforeDeleteEvent extends RelationalEventWithId {
 	 * @param entity the entity about to get deleted. Might be empty.
 	 * @param change the {@link AggregateChange} encoding the planned actions to be performed on the database.
 	 */
-	public <T> BeforeDeleteEvent(Specified id, Optional<Object> entity, AggregateChange change) {
+	public <T> BeforeDeleteEvent(Specified id, Optional<?> entity, AggregateChange change) {
 		super(id, entity, change);
 	}
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/BeforeSaveCallback.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2019 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.relational.core.mapping.event;
+
+import org.springframework.data.mapping.callback.EntityCallback;
+
+/**
+ * An {@link EntityCallback} that gets invoked before changes get applied to the database but after the aggregate got actually converted to a database change.
+ *
+ * @since 1.1
+ * @author Jens Schauder
+ */
+@FunctionalInterface
+public interface BeforeSaveCallback<T> extends EntityCallback<T> {
+
+	T onBeforeSave(T aggregate, Identifier id);
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/RelationalEventWithId.java

@@ -32,7 +32,7 @@ public class RelationalEventWithId extends SimpleRelationalEvent implements With
 
 	private final Specified id;
 
-	public RelationalEventWithId(Specified id, Optional<Object> entity, @Nullable AggregateChange change) {
+	public RelationalEventWithId(Specified id, Optional<?> entity, @Nullable AggregateChange change) {
 
 		super(id, entity, change);
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/SimpleRelationalEvent.java

@@ -35,7 +35,7 @@ class SimpleRelationalEvent extends ApplicationEvent implements RelationalEvent
 	private final Object entity;
 	private final AggregateChange change;
 
-	SimpleRelationalEvent(Identifier id, Optional<Object> entity, @Nullable AggregateChange change) {
+	SimpleRelationalEvent(Identifier id, Optional<?> entity, @Nullable AggregateChange change) {
 
 		super(id);
 
@@ -61,6 +61,15 @@ class SimpleRelationalEvent extends ApplicationEvent implements RelationalEvent
 		return Optional.ofNullable(entity);
 	}
 
+	/**
+	 * Returns the an {@link AggregateChange} instance representing the SQL statements performed by the action that
+	 * triggered this event.
+	 * 
+	 * @return Guaranteed to be not {@literal null}.
+	 * @deprecated There is currently no replacement for this. If something like this is required please create an issue
+	 *             outlining your use case.
+	 */
+	@Deprecated
 	public AggregateChange getChange() {
 		return change;
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/domain/support/RelationalAuditingCallback.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2018-2019 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.relational.domain.support;
+
+import lombok.RequiredArgsConstructor;
+
+import org.springframework.context.ApplicationListener;
+import org.springframework.core.Ordered;
+import org.springframework.data.auditing.IsNewAwareAuditingHandler;
+import org.springframework.data.relational.core.mapping.event.BeforeConvertCallback;
+import org.springframework.data.relational.core.mapping.event.BeforeSaveEvent;
+import org.springframework.data.relational.core.mapping.event.Identifier;
+
+/**
+ * {@link BeforeConvertCallback} to capture auditing information on persisting and updating entities.
+ * <p>
+ * An instance of this class gets registered when you enable auditing for Spring Data JDBC.
+ *
+ * @author Jens Schauder
+ */
+@RequiredArgsConstructor
+public class RelationalAuditingCallback implements BeforeConvertCallback, Ordered {
+
+	/**
+	 * The order used for this {@link org.springframework.context.event.EventListener}. Ordering ensures that this
+	 * {@link ApplicationListener} will run before other listeners without a specified priority.
+	 *
+	 * @see org.springframework.core.annotation.Order
+	 * @see Ordered
+	 */
+	public static final int AUDITING_ORDER = 100;
+
+	private final IsNewAwareAuditingHandler handler;
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.core.Ordered#getOrder()
+	 */
+	@Override
+	public int getOrder() {
+		return AUDITING_ORDER;
+	}
+
+	@Override
+	public Object onBeforeConvert(Object entity, Identifier id) {
+		return handler.markAudited(entity);
+	}
+}

spring-data-relational/src/main/java/org/springframework/data/relational/domain/support/RelationalAuditingEventListener.java

@@ -24,13 +24,13 @@ import org.springframework.data.relational.core.mapping.event.BeforeSaveEvent;
 
 /**
  * Spring JDBC event listener to capture auditing information on persisting and updating entities.
- * <p>
- * An instance of this class gets registered when you enable auditing for Spring Data JDBC.
  *
  * @author Kazuki Shimizu
  * @author Jens Schauder
  * @author Oliver Gierke
+ * @deprecated Use {@link RelationalAuditingCallback} instead.
  */
+@Deprecated
 @RequiredArgsConstructor
 public class RelationalAuditingEventListener implements ApplicationListener<BeforeSaveEvent>, Ordered {
 

src/main/asciidoc/jdbc.adoc

@@ -563,9 +563,9 @@ Note that the type used for prefixing the statement name is the name of the aggr
 |===
 
 [[jdbc.events]]
-== Events
+== Events and Callback
 
-Spring Data JDBC triggers events that get published to any matching `ApplicationListener` in the application context.
+Spring Data JDBC triggers events that get published to any matching `ApplicationListener` and `EntityCallback` beans in the application context.
 For example, the following listener gets invoked before an aggregate gets saved:
 
 ====
@@ -586,27 +586,34 @@ public ApplicationListener<BeforeSave> timeStampingSaveTime() {
 ----
 ====
 
-The following table describes the available events:
+The following table describes the available events and callbacks:
 
 .Available events
 |===
-| Event | When It Is Published
+| Event | `EntityCallback` | When It Is Published
 
 | {javadoc-base}org/springframework/data/relational/core/mapping/event/BeforeDeleteEvent.html[`BeforeDeleteEvent`]
+| {javadoc-base}org/springframework/data/relational/core/mapping/event/BeforeDeleteCallback.html[`BeforeDeleteCallback`]
 | Before an aggregate root gets deleted.
 
 | {javadoc-base}org/springframework/data/relational/core/mapping/event/AfterDeleteEvent.html[`AfterDeleteEvent`]
+| {javadoc-base}org/springframework/data/relational/core/mapping/event/AfterDeleteCallback.html[`AfterDeleteCallback`]
 | After an aggregate root gets deleted.
 
+| {javadoc-base}/org/springframework/data/relational/core/mapping/event/BeforeConvertEvent.html[`BeforeConvertEvent`]
+| {javadoc-base}/org/springframework/data/relational/core/mapping/event/BeforeConvertCallback.html[`BeforeConvertCallback`]
+| Before an aggregate root gets saved (that is, inserted or updated but after the decision about whether if it gets updated or deleted was made).
+
 | {javadoc-base}/org/springframework/data/relational/core/mapping/event/BeforeSaveEvent.html[`BeforeSaveEvent`]
+| {javadoc-base}/org/springframework/data/relational/core/mapping/event/BeforeSaveCallback.html[`BeforeSaveCallback`]
 | Before an aggregate root gets saved (that is, inserted or updated but after the decision about whether if it gets updated or deleted was made).
-The event has a reference to an {javadoc-base}/org/springframework/data/relational/core/conversion/AggregateChange.html[`AggregateChange`] instance.
-The instance can be modified by adding or removing {javadoc-base}/org/springframework/data/relational/core/conversion/DbAction.html[`DbAction`] instances.
 
 | {javadoc-base}org/springframework/data/relational/core/mapping/event/AfterSaveEvent.html[`AfterSaveEvent`]
+| {javadoc-base}org/springframework/data/relational/core/mapping/event/AfterSaveCallback.html[`AfterSaveCallback`]
 | After an aggregate root gets saved (that is, inserted or updated).
 
 | {javadoc-base}org/springframework/data/relational/core/mapping/event/AfterLoadEvent.html[`AfterLoadEvent`]
+| {javadoc-base}org/springframework/data/relational/core/mapping/event/AfterLoadCallback.html[`AfterLoadCallback`]
 | After an aggregate root gets created from a database `ResultSet` and all its property get set.
 |===