Improve handling of immutable classes.

Original Pull Request #1801
Closes #1800

src/main/java/org/springframework/data/elasticsearch/core/AbstractElasticsearchTemplate.java

@@ -188,7 +188,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 		IndexQuery query = getIndexQuery(entityAfterBeforeConvert);
 		doIndex(query, index);
 
-		T entityAfterAfterSave = maybeCallbackAfterSave(entityAfterBeforeConvert, index);
+		T entityAfterAfterSave = (T) maybeCallbackAfterSave(query.getObject(), index);
 
 		return entityAfterAfterSave;
 	}
@@ -215,13 +215,18 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 		List<IndexQuery> indexQueries = Streamable.of(entities).stream().map(this::getIndexQuery)
 				.collect(Collectors.toList());
 
-		if (!indexQueries.isEmpty()) {
-			List<IndexedObjectInformation> indexedObjectInformations = bulkIndex(indexQueries, index);
-			Iterator<IndexedObjectInformation> iterator = indexedObjectInformations.iterator();
-			entities.forEach(entity -> updateIndexedObject(entity, iterator.next()));
+		if (indexQueries.isEmpty()) {
+			return Collections.emptyList();
 		}
 
-		return indexQueries.stream().map(IndexQuery::getObject).map(entity -> (T) entity).collect(Collectors.toList());
+		List<IndexedObjectInformation> indexedObjectInformations = bulkIndex(indexQueries, index);
+		Iterator<IndexedObjectInformation> iterator = indexedObjectInformations.iterator();
+
+		// noinspection unchecked
+		return indexQueries.stream() //
+				.map(IndexQuery::getObject) //
+				.map(entity -> (T) updateIndexedObject(entity, iterator.next())) //
+				.collect(Collectors.toList()); //
 	}
 
 	@Override
@@ -419,7 +424,9 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 		Assert.notNull(query.getId(), "No document id defined for MoreLikeThisQuery");
 
 		MoreLikeThisQueryBuilder moreLikeThisQueryBuilder = requestFactory.moreLikeThisQueryBuilder(query, index);
-		return search(new NativeSearchQueryBuilder().withQuery(moreLikeThisQueryBuilder).withPageable(query.getPageable()).build(), clazz, index);
+		return search(
+				new NativeSearchQueryBuilder().withQuery(moreLikeThisQueryBuilder).withPageable(query.getPageable()).build(),
+				clazz, index);
 	}
 
 	@Override
@@ -611,7 +618,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 		}).collect(Collectors.toList());
 	}
 
-	protected void updateIndexedObject(Object entity, IndexedObjectInformation indexedObjectInformation) {
+	protected <T> T updateIndexedObject(T entity, IndexedObjectInformation indexedObjectInformation) {
 
 		ElasticsearchPersistentEntity<?> persistentEntity = elasticsearchConverter.getMappingContext()
 				.getPersistentEntity(entity.getClass());
@@ -621,22 +628,30 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 			ElasticsearchPersistentProperty idProperty = persistentEntity.getIdProperty();
 
 			// Only deal with text because ES generated Ids are strings!
-			if (idProperty != null && idProperty.getType().isAssignableFrom(String.class)) {
+			if (indexedObjectInformation.getId() != null && idProperty != null
+					&& idProperty.getType().isAssignableFrom(String.class)) {
 				propertyAccessor.setProperty(idProperty, indexedObjectInformation.getId());
 			}
 
 			if (indexedObjectInformation.getSeqNo() != null && indexedObjectInformation.getPrimaryTerm() != null
 					&& persistentEntity.hasSeqNoPrimaryTermProperty()) {
 				ElasticsearchPersistentProperty seqNoPrimaryTermProperty = persistentEntity.getSeqNoPrimaryTermProperty();
+				// noinspection ConstantConditions
 				propertyAccessor.setProperty(seqNoPrimaryTermProperty,
 						new SeqNoPrimaryTerm(indexedObjectInformation.getSeqNo(), indexedObjectInformation.getPrimaryTerm()));
 			}
 
 			if (indexedObjectInformation.getVersion() != null && persistentEntity.hasVersionProperty()) {
 				ElasticsearchPersistentProperty versionProperty = persistentEntity.getVersionProperty();
+				// noinspection ConstantConditions
 				propertyAccessor.setProperty(versionProperty, indexedObjectInformation.getVersion());
 			}
+
+			// noinspection unchecked
+			T updatedEntity = (T) propertyAccessor.getBean();
+			return updatedEntity;
 		}
+		return entity;
 	}
 
 	ElasticsearchPersistentEntity<?> getRequiredPersistentEntity(Class<?> clazz) {
@@ -807,13 +822,16 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 
 	protected void updateIndexedObjectsWithQueries(List<?> queries,
 			List<IndexedObjectInformation> indexedObjectInformations) {
+
 		for (int i = 0; i < queries.size(); i++) {
 			Object query = queries.get(i);
+
 			if (query instanceof IndexQuery) {
 				IndexQuery indexQuery = (IndexQuery) query;
 				Object queryObject = indexQuery.getObject();
+
 				if (queryObject != null) {
-					updateIndexedObject(queryObject, indexedObjectInformations.get(i));
+					indexQuery.setObject(updateIndexedObject(queryObject, indexedObjectInformations.get(i)));
 				}
 			}
 		}
@@ -848,6 +866,10 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 			}
 
 			T entity = reader.read(type, document);
+			IndexedObjectInformation indexedObjectInformation = IndexedObjectInformation.of(
+					document.hasId() ? document.getId() : null, document.getSeqNo(), document.getPrimaryTerm(),
+					document.getVersion());
+			entity = updateIndexedObject(entity, indexedObjectInformation);
 			return maybeCallbackAfterConvert(entity, document, index);
 		}
 	}

src/main/java/org/springframework/data/elasticsearch/core/ElasticsearchRestTemplate.java

@@ -157,9 +157,10 @@ public class ElasticsearchRestTemplate extends AbstractElasticsearchTemplate {
 		IndexResponse indexResponse = execute(client -> client.index(request, RequestOptions.DEFAULT));
 
 		Object queryObject = query.getObject();
+
 		if (queryObject != null) {
-			updateIndexedObject(queryObject, IndexedObjectInformation.of(indexResponse.getId(), indexResponse.getSeqNo(),
-					indexResponse.getPrimaryTerm(), indexResponse.getVersion()));
+			query.setObject(updateIndexedObject(queryObject, IndexedObjectInformation.of(indexResponse.getId(),
+					indexResponse.getSeqNo(), indexResponse.getPrimaryTerm(), indexResponse.getVersion())));
 		}
 
 		return indexResponse.getId();
@@ -168,6 +169,7 @@ public class ElasticsearchRestTemplate extends AbstractElasticsearchTemplate {
 	@Override
 	@Nullable
 	public <T> T get(String id, Class<T> clazz, IndexCoordinates index) {
+
 		GetRequest request = requestFactory.getRequest(id, routingResolver.getRouting(), index);
 		GetResponse response = execute(client -> client.get(request, RequestOptions.DEFAULT));
 

src/main/java/org/springframework/data/elasticsearch/core/ElasticsearchTemplate.java

@@ -177,8 +177,8 @@ public class ElasticsearchTemplate extends AbstractElasticsearchTemplate {
 
 		Object queryObject = query.getObject();
 		if (queryObject != null) {
-			updateIndexedObject(queryObject, IndexedObjectInformation.of(documentId, response.getSeqNo(),
-					response.getPrimaryTerm(), response.getVersion()));
+			query.setObject(updateIndexedObject(queryObject, IndexedObjectInformation.of(documentId, response.getSeqNo(),
+					response.getPrimaryTerm(), response.getVersion())));
 		}
 
 		return documentId;

src/main/java/org/springframework/data/elasticsearch/core/EntityOperations.java

@@ -477,7 +477,6 @@ class EntityOperations {
 	 */
 	private static class AdaptibleMappedEntity<T> extends MappedEntity<T> implements AdaptibleEntity<T> {
 
-		private final T bean;
 		private final ElasticsearchPersistentEntity<?> entity;
 		private final ConvertingPropertyAccessor<T> propertyAccessor;
 		private final IdentifierAccessor identifierAccessor;
@@ -490,7 +489,6 @@ class EntityOperations {
 
 			super(entity, identifierAccessor, propertyAccessor);
 
-			this.bean = bean;
 			this.entity = entity;
 			this.propertyAccessor = propertyAccessor;
 			this.identifierAccessor = identifierAccessor;
@@ -510,6 +508,11 @@ class EntityOperations {
 					new ConvertingPropertyAccessor<>(propertyAccessor, conversionService), conversionService, routingResolver);
 		}
 
+		@Override
+		public T getBean() {
+			return propertyAccessor.getBean();
+		}
+
 		@Nullable
 		@Override
 		public T populateIdIfNecessary(@Nullable Object id) {
@@ -584,7 +587,7 @@ class EntityOperations {
 		@Override
 		public String getRouting() {
 
-			String routing = routingResolver.getRouting(bean);
+			String routing = routingResolver.getRouting(propertyAccessor.getBean());
 
 			if (routing != null) {
 				return routing;

src/main/java/org/springframework/data/elasticsearch/core/IndexedObjectInformation.java

@@ -25,12 +25,12 @@ import org.springframework.lang.Nullable;
  * @since 4.1
  */
 public class IndexedObjectInformation {
-	private final String id;
+	@Nullable private final String id;
 	@Nullable private final Long seqNo;
 	@Nullable private final Long primaryTerm;
 	@Nullable private final Long version;
 
-	private IndexedObjectInformation(String id, @Nullable Long seqNo, @Nullable Long primaryTerm,
+	private IndexedObjectInformation(@Nullable String id, @Nullable Long seqNo, @Nullable Long primaryTerm,
 			@Nullable Long version) {
 		this.id = id;
 		this.seqNo = seqNo;
@@ -38,11 +38,12 @@ public class IndexedObjectInformation {
 		this.version = version;
 	}
 
-	public static IndexedObjectInformation of(String id, @Nullable Long seqNo, @Nullable Long primaryTerm,
+	public static IndexedObjectInformation of(@Nullable String id, @Nullable Long seqNo, @Nullable Long primaryTerm,
 			@Nullable Long version) {
 		return new IndexedObjectInformation(id, seqNo, primaryTerm, version);
 	}
 
+	@Nullable
 	public String getId() {
 		return id;
 	}

src/main/java/org/springframework/data/elasticsearch/core/ReactiveElasticsearchTemplate.java

@@ -275,27 +275,42 @@ public class ReactiveElasticsearchTemplate implements ReactiveElasticsearchOpera
 	}
 
 	private <T> T updateIndexedObject(T entity, IndexedObjectInformation indexedObjectInformation) {
-		AdaptibleEntity<T> adaptibleEntity = operations.forEntity(entity, converter.getConversionService(),
-				routingResolver);
-		adaptibleEntity.populateIdIfNecessary(indexedObjectInformation.getId());
 
-		ElasticsearchPersistentEntity<?> persistentEntity = getPersistentEntityFor(entity.getClass());
+		ElasticsearchPersistentEntity<?> persistentEntity = converter.getMappingContext()
+				.getPersistentEntity(entity.getClass());
+
 		if (persistentEntity != null) {
 			PersistentPropertyAccessor<Object> propertyAccessor = persistentEntity.getPropertyAccessor(entity);
+			ElasticsearchPersistentProperty idProperty = persistentEntity.getIdProperty();
+
+			// Only deal with text because ES generated Ids are strings!
+			if (indexedObjectInformation.getId() != null && idProperty != null
+					&& idProperty.getType().isAssignableFrom(String.class)) {
+				propertyAccessor.setProperty(idProperty, indexedObjectInformation.getId());
+			}
 
 			if (indexedObjectInformation.getSeqNo() != null && indexedObjectInformation.getPrimaryTerm() != null
 					&& persistentEntity.hasSeqNoPrimaryTermProperty()) {
 				ElasticsearchPersistentProperty seqNoPrimaryTermProperty = persistentEntity.getSeqNoPrimaryTermProperty();
+				// noinspection ConstantConditions
 				propertyAccessor.setProperty(seqNoPrimaryTermProperty,
 						new SeqNoPrimaryTerm(indexedObjectInformation.getSeqNo(), indexedObjectInformation.getPrimaryTerm()));
 			}
 
 			if (indexedObjectInformation.getVersion() != null && persistentEntity.hasVersionProperty()) {
 				ElasticsearchPersistentProperty versionProperty = persistentEntity.getVersionProperty();
+				// noinspection ConstantConditions
 				propertyAccessor.setProperty(versionProperty, indexedObjectInformation.getVersion());
 			}
-		}
 
+			// noinspection unchecked
+			T updatedEntity = (T) propertyAccessor.getBean();
+			return updatedEntity;
+		} else {
+			AdaptibleEntity<T> adaptibleEntity = operations.forEntity(entity, converter.getConversionService(),
+					routingResolver);
+			adaptibleEntity.populateIdIfNecessary(indexedObjectInformation.getId());
+		}
 		return entity;
 	}
 
@@ -457,7 +472,7 @@ public class ReactiveElasticsearchTemplate implements ReactiveElasticsearchOpera
 
 		DocumentCallback<T> callback = new ReadDocumentCallback<>(converter, entityType, index);
 
-		return doGet(id, index).flatMap(it -> callback.toEntity(DocumentAdapters.from(it)));
+		return doGet(id, index).flatMap(response -> callback.toEntity(DocumentAdapters.from(response)));
 	}
 
 	private Mono<GetResult> doGet(String id, IndexCoordinates index) {
@@ -1097,6 +1112,10 @@ public class ReactiveElasticsearchTemplate implements ReactiveElasticsearchOpera
 			}
 
 			T entity = reader.read(type, document);
+			IndexedObjectInformation indexedObjectInformation = IndexedObjectInformation.of(
+					document.hasId() ? document.getId() : null, document.getSeqNo(), document.getPrimaryTerm(),
+					document.getVersion());
+			entity = updateIndexedObject(entity, indexedObjectInformation);
 			return maybeCallAfterConvert(entity, document, index);
 		}
 	}

src/main/java/org/springframework/data/elasticsearch/core/join/JoinField.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.elasticsearch.core.join;
 
+import org.springframework.data.annotation.PersistenceConstructor;
 import org.springframework.lang.Nullable;
 
 /**
@@ -35,6 +36,7 @@ public class JoinField<ID> {
 		this(name, null);
 	}
 
+	@PersistenceConstructor
 	public JoinField(String name, @Nullable ID parent) {
 		this.name = name;
 		this.parent = parent;

src/main/java/org/springframework/data/elasticsearch/core/mapping/SimpleElasticsearchPersistentEntity.java

@@ -35,7 +35,6 @@ import org.springframework.data.mapping.MappingException;
 import org.springframework.data.mapping.PropertyHandler;
 import org.springframework.data.mapping.model.BasicPersistentEntity;
 import org.springframework.data.mapping.model.FieldNamingStrategy;
-import org.springframework.data.mapping.model.PersistentPropertyAccessorFactory;
 import org.springframework.data.spel.ExpressionDependencies;
 import org.springframework.data.util.Lazy;
 import org.springframework.data.util.TypeInformation;
@@ -238,19 +237,6 @@ public class SimpleElasticsearchPersistentEntity<T> extends BasicPersistentEntit
 				getType());
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mapping.model.BasicPersistentEntity#setPersistentPropertyAccessorFactory(org.springframework.data.mapping.model.PersistentPropertyAccessorFactory)
-	 */
-	@SuppressWarnings("SpellCheckingInspection")
-	@Override
-	public void setPersistentPropertyAccessorFactory(PersistentPropertyAccessorFactory factory) {
-
-		// Do nothing to avoid the usage of ClassGeneratingPropertyAccessorFactory for now
-		// DATACMNS-1322 switches to proper immutability behavior which Spring Data Elasticsearch
-		// cannot yet implement
-	}
-
 	@Nullable
 	@Override
 	public ElasticsearchPersistentProperty getPersistentPropertyWithFieldName(String fieldName) {

src/main/java/org/springframework/data/elasticsearch/core/mapping/SimpleElasticsearchPersistentProperty.java

@@ -279,11 +279,6 @@ public class SimpleElasticsearchPersistentProperty extends
 		throw new UnsupportedOperationException();
 	}
 
-	@Override
-	public boolean isImmutable() {
-		return false;
-	}
-
 	@Override
 	public boolean isSeqNoPrimaryTermProperty() {
 		return isSeqNoPrimaryTerm;

src/test/java/org/springframework/data/elasticsearch/core/ElasticsearchTemplateTests.java

@@ -60,7 +60,6 @@ import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.FieldSortBuilder;
 import org.elasticsearch.search.sort.SortBuilders;
 import org.elasticsearch.search.sort.SortOrder;
-import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -137,7 +136,8 @@ public abstract class ElasticsearchTemplateTests {
 	@BeforeEach
 	public void before() {
 		indexOperations = operations.indexOps(SampleEntity.class);
-		deleteIndices();
+
+		operations.indexOps(IndexCoordinates.of("*")).delete();
 
 		indexOperations.create();
 		indexOperations.putMapping(SampleEntity.class);
@@ -155,29 +155,6 @@ public abstract class ElasticsearchTemplateTests {
 		indexOpsJoinEntity.putMapping(SampleJoinEntity.class);
 	}
 
-	@AfterEach
-	public void after() {
-
-		deleteIndices();
-	}
-
-	private void deleteIndices() {
-
-		indexOperations.delete();
-		operations.indexOps(SampleEntityUUIDKeyed.class).delete();
-		operations.indexOps(UseServerConfigurationEntity.class).delete();
-		operations.indexOps(SampleMappingEntity.class).delete();
-		operations.indexOps(Book.class).delete();
-		operations.indexOps(IndexCoordinates.of(INDEX_1_NAME)).delete();
-		operations.indexOps(IndexCoordinates.of(INDEX_2_NAME)).delete();
-		operations.indexOps(IndexCoordinates.of(INDEX_3_NAME)).delete();
-		operations.indexOps(SearchHitsEntity.class).delete();
-		operations.indexOps(HighlightEntity.class).delete();
-		operations.indexOps(OptimisticEntity.class).delete();
-		operations.indexOps(OptimisticAndVersionedEntity.class).delete();
-		operations.indexOps(IndexCoordinates.of(INDEX_NAME_JOIN_SAMPLE_ENTITY)).delete();
-	}
-
 	@Test // DATAES-106
 	public void shouldReturnCountForGivenCriteriaQuery() {
 
@@ -1126,7 +1103,8 @@ public abstract class ElasticsearchTemplateTests {
 		Collection<String> ids = IntStream.rangeClosed(1, 10).mapToObj(i -> nextIdAsString()).collect(Collectors.toList());
 		ids.add(referenceId);
 		ids.stream()
-				.map(id -> getIndexQuery(SampleEntity.builder().id(id).message(sampleMessage).version(System.currentTimeMillis()).build()))
+				.map(id -> getIndexQuery(
+						SampleEntity.builder().id(id).message(sampleMessage).version(System.currentTimeMillis()).build()))
 				.forEach(indexQuery -> operations.index(indexQuery, index));
 		indexOperations.refresh();
 
@@ -1141,7 +1119,8 @@ public abstract class ElasticsearchTemplateTests {
 		assertThat(searchHits.getTotalHits()).isEqualTo(10);
 		assertThat(searchHits.getSearchHits()).hasSize(5);
 
-		Collection<String> returnedIds = searchHits.getSearchHits().stream().map(SearchHit::getId).collect(Collectors.toList());
+		Collection<String> returnedIds = searchHits.getSearchHits().stream().map(SearchHit::getId)
+				.collect(Collectors.toList());
 
 		moreLikeThisQuery.setPageable(PageRequest.of(1, 5));
 
@@ -3588,6 +3567,24 @@ public abstract class ElasticsearchTemplateTests {
 		assertThat(explanation).isNotNull();
 	}
 
+	@Test // #1800
+	@DisplayName("should work with immutable classes")
+	void shouldWorkWithImmutableClasses() {
+
+		ImmutableEntity entity = new ImmutableEntity(null, "some text", null);
+
+		ImmutableEntity saved = operations.save(entity);
+
+		assertThat(saved).isNotNull();
+		assertThat(saved.getId()).isNotEmpty();
+		SeqNoPrimaryTerm seqNoPrimaryTerm = saved.getSeqNoPrimaryTerm();
+		assertThat(seqNoPrimaryTerm).isNotNull();
+
+		ImmutableEntity retrieved = operations.get(saved.getId(), ImmutableEntity.class);
+
+		assertThat(retrieved).isEqualTo(saved);
+	}
+
 	// region entities
 	@Document(indexName = INDEX_NAME_SAMPLE_ENTITY)
 	@Setting(shards = 1, replicas = 0, refreshInterval = "-1")
@@ -4366,5 +4363,61 @@ public abstract class ElasticsearchTemplateTests {
 			this.text = text;
 		}
 	}
-	//endregion
+
+	@Document(indexName = "immutable-class")
+	private static final class ImmutableEntity {
+		@Id private final String id;
+		@Field(type = FieldType.Text) private final String text;
+		@Nullable private final SeqNoPrimaryTerm seqNoPrimaryTerm;
+
+		public ImmutableEntity(@Nullable String id, String text, @Nullable SeqNoPrimaryTerm seqNoPrimaryTerm) {
+			this.id = id;
+			this.text = text;
+			this.seqNoPrimaryTerm = seqNoPrimaryTerm;
+		}
+
+		public String getId() {
+			return id;
+		}
+
+		public String getText() {
+			return text;
+		}
+
+		@Nullable
+		public SeqNoPrimaryTerm getSeqNoPrimaryTerm() {
+			return seqNoPrimaryTerm;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (this == o)
+				return true;
+			if (o == null || getClass() != o.getClass())
+				return false;
+
+			ImmutableEntity that = (ImmutableEntity) o;
+
+			if (!id.equals(that.id))
+				return false;
+			if (!text.equals(that.text))
+				return false;
+			return seqNoPrimaryTerm != null ? seqNoPrimaryTerm.equals(that.seqNoPrimaryTerm) : that.seqNoPrimaryTerm == null;
+		}
+
+		@Override
+		public int hashCode() {
+			int result = id.hashCode();
+			result = 31 * result + text.hashCode();
+			result = 31 * result + (seqNoPrimaryTerm != null ? seqNoPrimaryTerm.hashCode() : 0);
+			return result;
+		}
+
+		@Override
+		public String toString() {
+			return "ImmutableEntity{" + "id='" + id + '\'' + ", text='" + text + '\'' + ", seqNoPrimaryTerm="
+					+ seqNoPrimaryTerm + '}';
+		}
+	}
+	// endregion
 }

src/test/java/org/springframework/data/elasticsearch/core/ReactiveElasticsearchTemplateIntegrationTests.java

@@ -36,6 +36,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
@@ -64,6 +65,7 @@ import org.springframework.data.domain.Sort;
 import org.springframework.data.elasticsearch.UncategorizedElasticsearchException;
 import org.springframework.data.elasticsearch.annotations.Document;
 import org.springframework.data.elasticsearch.annotations.Field;
+import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.annotations.Mapping;
 import org.springframework.data.elasticsearch.annotations.Setting;
 import org.springframework.data.elasticsearch.client.reactive.ReactiveElasticsearchClient;
@@ -1149,6 +1151,26 @@ public class ReactiveElasticsearchTemplateIntegrationTests {
 		}).verifyComplete();
 	}
 
+	@Test // #1800
+	@DisplayName("should work with immutable classes")
+	void shouldWorkWithImmutableClasses() {
+
+		ImmutableEntity entity = new ImmutableEntity(null, "some text", null);
+		AtomicReference<ImmutableEntity> savedEntity = new AtomicReference<>();
+
+		template.save(entity).as(StepVerifier::create).consumeNextWith(saved -> {
+			assertThat(saved).isNotNull();
+			savedEntity.set(saved);
+			assertThat(saved.getId()).isNotEmpty();
+			SeqNoPrimaryTerm seqNoPrimaryTerm = saved.getSeqNoPrimaryTerm();
+			assertThat(seqNoPrimaryTerm).isNotNull();
+		}).verifyComplete();
+
+		template.get(savedEntity.get().getId(), ImmutableEntity.class).as(StepVerifier::create)
+				.consumeNextWith(retrieved -> {
+					assertThat(retrieved).isEqualTo(savedEntity.get());
+				}).verifyComplete();
+	}
 	// endregion
 
 	// region Helper functions
@@ -1243,8 +1265,10 @@ public class ReactiveElasticsearchTemplateIntegrationTests {
 
 		@Override
 		public boolean equals(Object o) {
-			if (this == o) return true;
-			if (o == null || getClass() != o.getClass()) return false;
+			if (this == o)
+				return true;
+			if (o == null || getClass() != o.getClass())
+				return false;
 
 			Message message1 = (Message) o;
 
@@ -1301,14 +1325,19 @@ public class ReactiveElasticsearchTemplateIntegrationTests {
 
 		@Override
 		public boolean equals(Object o) {
-			if (this == o) return true;
-			if (o == null || getClass() != o.getClass()) return false;
+			if (this == o)
+				return true;
+			if (o == null || getClass() != o.getClass())
+				return false;
 
 			SampleEntity that = (SampleEntity) o;
 
-			if (rate != that.rate) return false;
-			if (id != null ? !id.equals(that.id) : that.id != null) return false;
-			if (message != null ? !message.equals(that.message) : that.message != null) return false;
+			if (rate != that.rate)
+				return false;
+			if (id != null ? !id.equals(that.id) : that.id != null)
+				return false;
+			if (message != null ? !message.equals(that.message) : that.message != null)
+				return false;
 			return version != null ? version.equals(that.version) : that.version == null;
 		}
 
@@ -1440,5 +1469,60 @@ public class ReactiveElasticsearchTemplateIntegrationTests {
 		}
 	}
 
+	@Document(indexName = "immutable-class")
+	private static final class ImmutableEntity {
+		@Id private final String id;
+		@Field(type = FieldType.Text) private final String text;
+		@Nullable private final SeqNoPrimaryTerm seqNoPrimaryTerm;
+
+		public ImmutableEntity(@Nullable String id, String text, @Nullable SeqNoPrimaryTerm seqNoPrimaryTerm) {
+			this.id = id;
+			this.text = text;
+			this.seqNoPrimaryTerm = seqNoPrimaryTerm;
+		}
+
+		public String getId() {
+			return id;
+		}
+
+		public String getText() {
+			return text;
+		}
+
+		@Nullable
+		public SeqNoPrimaryTerm getSeqNoPrimaryTerm() {
+			return seqNoPrimaryTerm;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (this == o)
+				return true;
+			if (o == null || getClass() != o.getClass())
+				return false;
+
+			ImmutableEntity that = (ImmutableEntity) o;
+
+			if (!id.equals(that.id))
+				return false;
+			if (!text.equals(that.text))
+				return false;
+			return seqNoPrimaryTerm != null ? seqNoPrimaryTerm.equals(that.seqNoPrimaryTerm) : that.seqNoPrimaryTerm == null;
+		}
+
+		@Override
+		public int hashCode() {
+			int result = id.hashCode();
+			result = 31 * result + text.hashCode();
+			result = 31 * result + (seqNoPrimaryTerm != null ? seqNoPrimaryTerm.hashCode() : 0);
+			return result;
+		}
+
+		@Override
+		public String toString() {
+			return "ImmutableEntity{" + "id='" + id + '\'' + ", text='" + text + '\'' + ", seqNoPrimaryTerm="
+					+ seqNoPrimaryTerm + '}';
+		}
+	}
 	// endregion
 }

src/test/java/org/springframework/data/elasticsearch/immutable/ImmutableElasticsearchRepositoryTests.java

@@ -25,6 +25,7 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.data.annotation.PersistenceConstructor;
 import org.springframework.data.elasticsearch.annotations.Document;
 import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
 import org.springframework.data.elasticsearch.core.IndexOperations;
@@ -95,11 +96,16 @@ public class ImmutableElasticsearchRepositoryTests {
 	static class ImmutableEntity {
 		private final String id, name;
 
-		public ImmutableEntity(String name) {
-			this.id = null;
+		@PersistenceConstructor
+		public ImmutableEntity(String id, String name) {
+			this.id = id;
 			this.name = name;
 		}
 
+		public ImmutableEntity(String name) {
+			this(null, name);
+		}
+
 		public String getId() {
 			return id;
 		}