Mappingbuilder uses the typeKey from the ElasticsearchTypeMapper instance.

Original Pull Request  #2044

src/main/java/org/springframework/data/elasticsearch/core/convert/DefaultElasticsearchTypeMapper.java

@@ -67,14 +67,17 @@ public class DefaultElasticsearchTypeMapper extends DefaultTypeMapper<Map<String
 		this.typeKey = typeKey;
 	}
 
-	/*
+	@Override
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.convert.MongoTypeMapper#isTypeKey(java.lang.String)
-	 */
 	public boolean isTypeKey(String key) {
 		return typeKey != null && typeKey.equals(key);
 	}
 
+	@Override
+	@Nullable
+	public String getTypeKey() {
+		return typeKey;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.convert.DefaultTypeMapper#getFallbackTypeFor(java.lang.Object)

src/main/java/org/springframework/data/elasticsearch/core/convert/ElasticsearchTypeMapper.java

@@ -21,6 +21,7 @@ import org.springframework.data.convert.TypeMapper;
 import org.springframework.data.elasticsearch.core.mapping.ElasticsearchPersistentEntity;
 import org.springframework.data.elasticsearch.core.mapping.ElasticsearchPersistentProperty;
 import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.lang.Nullable;
 
 /**
  * Elasticsearch specific {@link TypeMapper} definition.
@@ -39,6 +40,13 @@ public interface ElasticsearchTypeMapper extends TypeMapper<Map<String, Object>>
 	 */
 	boolean isTypeKey(String key);
 
+	/**
+	 * @return the type key.
+	 * @since 4.4
+	 */
+	@Nullable
+	String getTypeKey();
+
 	default boolean containsTypeInformation(Map<String, Object> source) {
 		return readType(source) != null;
 	}

src/main/java/org/springframework/data/elasticsearch/core/convert/MappingElasticsearchConverter.java

@@ -92,6 +92,7 @@ public class MappingElasticsearchConverter
 	private CustomConversions conversions = new ElasticsearchCustomConversions(Collections.emptyList());
 	private final SpELContext spELContext = new SpELContext(new MapAccessor());
 	private final EntityInstantiators instantiators = new EntityInstantiators();
+	private final ElasticsearchTypeMapper typeMapper;
 
 	public MappingElasticsearchConverter(
 			MappingContext<? extends ElasticsearchPersistentEntity<?>, ElasticsearchPersistentProperty> mappingContext) {
@@ -106,6 +107,7 @@ public class MappingElasticsearchConverter
 
 		this.mappingContext = mappingContext;
 		this.conversionService = conversionService != null ? conversionService : new DefaultConversionService();
+		this.typeMapper = ElasticsearchTypeMapper.create(mappingContext);
 	}
 
 	@Override
@@ -145,12 +147,16 @@ public class MappingElasticsearchConverter
 		conversions.registerConvertersIn(conversionService);
 	}
 
+	public ElasticsearchTypeMapper getTypeMapper() {
+		return typeMapper;
+	}
+
 	// region read/write
 
 	@Override
 	public <R> R read(Class<R> type, Document source) {
 
-		Reader reader = new Reader(mappingContext, conversionService, conversions, spELContext, instantiators);
+		Reader reader = new Reader(mappingContext, conversionService, conversions, typeMapper, spELContext, instantiators);
 		return reader.read(type, source);
 	}
 
@@ -159,7 +165,7 @@ public class MappingElasticsearchConverter
 
 		Assert.notNull(source, "source to map must not be null");
 
-		Writer writer = new Writer(mappingContext, conversionService, conversions);
+		Writer writer = new Writer(mappingContext, conversionService, conversions, typeMapper);
 		writer.write(source, sink);
 	}
 
@@ -176,11 +182,11 @@ public class MappingElasticsearchConverter
 
 		private Base(
 				MappingContext<? extends ElasticsearchPersistentEntity<?>, ElasticsearchPersistentProperty> mappingContext,
-				GenericConversionService conversionService, CustomConversions conversions) {
+				GenericConversionService conversionService, CustomConversions conversions, ElasticsearchTypeMapper typeMapper) {
 			this.mappingContext = mappingContext;
 			this.conversionService = conversionService;
 			this.conversions = conversions;
-			this.typeMapper = ElasticsearchTypeMapper.create(mappingContext);
+			this.typeMapper = typeMapper;
 		}
 	}
 
@@ -195,10 +201,10 @@ public class MappingElasticsearchConverter
 
 		public Reader(
 				MappingContext<? extends ElasticsearchPersistentEntity<?>, ElasticsearchPersistentProperty> mappingContext,
-				GenericConversionService conversionService, CustomConversions conversions, SpELContext spELContext,
+				GenericConversionService conversionService, CustomConversions conversions, ElasticsearchTypeMapper typeMapper,
-				EntityInstantiators instantiators) {
+				SpELContext spELContext, EntityInstantiators instantiators) {
 
-			super(mappingContext, conversionService, conversions);
+			super(mappingContext, conversionService, conversions, typeMapper);
 			this.spELContext = spELContext;
 			this.instantiators = instantiators;
 		}
@@ -670,8 +676,8 @@ public class MappingElasticsearchConverter
 
 		public Writer(
 				MappingContext<? extends ElasticsearchPersistentEntity<?>, ElasticsearchPersistentProperty> mappingContext,
-				GenericConversionService conversionService, CustomConversions conversions) {
+				GenericConversionService conversionService, CustomConversions conversions, ElasticsearchTypeMapper typeMapper) {
-			super(mappingContext, conversionService, conversions);
+			super(mappingContext, conversionService, conversions, typeMapper);
 		}
 
 		void write(Object source, Document sink) {

src/main/java/org/springframework/data/elasticsearch/core/index/MappingBuilder.java

@@ -35,6 +35,8 @@ import org.springframework.data.elasticsearch.annotations.*;
 import org.springframework.data.elasticsearch.backend.elasticsearch7.ElasticsearchRestTemplate;
 import org.springframework.data.elasticsearch.core.ResourceUtil;
 import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;
+import org.springframework.data.elasticsearch.core.convert.ElasticsearchTypeMapper;
+import org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter;
 import org.springframework.data.elasticsearch.core.document.Document;
 import org.springframework.data.elasticsearch.core.mapping.ElasticsearchPersistentEntity;
 import org.springframework.data.elasticsearch.core.mapping.ElasticsearchPersistentProperty;
@@ -88,7 +90,7 @@ public class MappingBuilder {
 	private static final String COMPLETION_MAX_INPUT_LENGTH = "max_input_length";
 	private static final String COMPLETION_CONTEXTS = "contexts";
 
-	private static final String TYPEHINT_PROPERTY = "_class";
+	private static final String TYPEHINT_PROPERTY = ElasticsearchTypeMapper.DEFAULT_TYPE_KEY;
 
 	private static final String TYPE_DYNAMIC = "dynamic";
 	private static final String TYPE_VALUE_KEYWORD = "keyword";
@@ -189,7 +191,17 @@ public class MappingBuilder {
 		private void writeTypeHintMapping(ObjectNode propertiesNode) throws IOException {
 
 			if (writeTypeHints) {
-				propertiesNode.set(TYPEHINT_PROPERTY, objectMapper.createObjectNode() //
+				String typeHintProperty = null;
+
+				if (elasticsearchConverter instanceof MappingElasticsearchConverter) {
+					typeHintProperty = ((MappingElasticsearchConverter) elasticsearchConverter).getTypeMapper().getTypeKey();
+				}
+
+				if (typeHintProperty == null) {
+					typeHintProperty = TYPEHINT_PROPERTY;
+				}
+
+				propertiesNode.set(typeHintProperty, objectMapper.createObjectNode() //
 						.put(FIELD_PARAM_TYPE, TYPE_VALUE_KEYWORD) //
 						.put(FIELD_PARAM_INDEX, false) //
 						.put(FIELD_PARAM_DOC_VALUES, false));