Support serialization for DynamicTemplates.

Signed-off-by: Youssef Aouichaoui <youssef3wi@icloud.com>

Author: youssef3wi

src/main/java/org/springframework/data/elasticsearch/annotations/Field.java

@@ -252,4 +252,11 @@
 	 * @since 5.4
 	 */
 	String mappedTypeName() default "";
+
+	/**
+	 * Maps your data beyond the dynamic field mapping rules.
+	 * 
+	 * @since 5.4
+	 */
+	boolean dynamicTemplate() default false;
 }

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

@@ -1035,7 +1035,14 @@ protected void writeProperty(ElasticsearchPersistentProperty property, Object va
 
 			if (valueType.isMap()) {
 				Map<String, Object> mapDbObj = createMap((Map<?, ?>) value, property);
-				sink.set(property, mapDbObj);
+				if (property.isDynamicFieldMapping()) {
+					for (Entry<String, Object> entry : mapDbObj.entrySet()) {
+						sink.set(entry.getKey(), entry.getValue());
+					}
+				} else {
+					sink.set(property, mapDbObj);
+				}
+				
 				return;
 			}
 
@@ -1499,7 +1506,11 @@ public void set(ElasticsearchPersistentProperty property, @Nullable Object value
 				}
 			}
 
-			target.put(property.getFieldName(), value);
+			set(property.getFieldName(), value);
+		}
+
+		public void set(String key, @Nullable Object value) {
+			target.put(key, value);
 		}
 
 		private Map<String, Object> getAsMap(Object result) {

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

@@ -110,6 +110,13 @@ public interface ElasticsearchPersistentProperty extends PersistentProperty<Elas
 	 */
 	boolean isIndexedIndexNameProperty();
 
+	/**
+	 * Maps your data beyond the dynamic field mapping rules.
+	 *
+	 * @since 5.4
+	 */
+	boolean isDynamicFieldMapping();
+
 	/**
 	 * calls {@link #getActualType()} but returns null when an exception is thrown
 	 *

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

@@ -86,6 +86,7 @@ public class SimpleElasticsearchPersistentProperty extends
 	@Nullable private PropertyValueConverter propertyValueConverter;
 	private final boolean storeNullValue;
 	private final boolean storeEmptyValue;
+	private final boolean isDynamicFieldMapping;
 
 	public SimpleElasticsearchPersistentProperty(Property property,
 			PersistentEntity<?, ElasticsearchPersistentProperty> owner, SimpleTypeHolder simpleTypeHolder) {
@@ -114,6 +115,7 @@ public SimpleElasticsearchPersistentProperty(Property property,
 				: isMultiField && getRequiredAnnotation(MultiField.class).mainField().storeNullValue();
 		storeEmptyValue = isField ? getRequiredAnnotation(Field.class).storeEmptyValue()
 				: !isMultiField || getRequiredAnnotation(MultiField.class).mainField().storeEmptyValue();
+		isDynamicFieldMapping = isField && getRequiredAnnotation(Field.class).dynamicTemplate();
 	}
 
 	@Override
@@ -393,4 +395,9 @@ public boolean isCompletionProperty() {
 	public boolean isIndexedIndexNameProperty() {
 		return isAnnotationPresent(IndexedIndexName.class);
 	}
+
+	@Override
+	public boolean isDynamicFieldMapping() {
+		return isDynamicFieldMapping;
+	}
 }

src/test/java/org/springframework/data/elasticsearch/core/index/MappingBuilderIntegrationTests.java

@@ -16,8 +16,10 @@
 
 package org.springframework.data.elasticsearch.core.index;
 
+import static java.util.UUID.randomUUID;
 import static org.assertj.core.api.Assertions.*;
 import static org.springframework.data.elasticsearch.annotations.FieldType.*;
+import static org.springframework.data.elasticsearch.core.query.StringQuery.MATCH_ALL;
 
 import java.time.Instant;
 import java.time.LocalDate;
@@ -40,7 +42,9 @@
 import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
 import org.springframework.data.elasticsearch.core.IndexOperations;
 import org.springframework.data.elasticsearch.core.MappingContextBaseTests;
+import org.springframework.data.elasticsearch.core.SearchHits;
 import org.springframework.data.elasticsearch.core.mapping.IndexCoordinates;
+import org.springframework.data.elasticsearch.core.query.StringQuery;
 import org.springframework.data.elasticsearch.junit.jupiter.SpringIntegrationTest;
 import org.springframework.data.elasticsearch.utils.IndexNameProvider;
 import org.springframework.lang.Nullable;
@@ -280,6 +284,24 @@ void shouldWriteMappingWithFieldAliases() {
 		operations.indexOps(FieldAliasEntity.class).createWithMapping();
 	}
 
+	@Test
+	void shouldMapDynamicFields() {
+		// Given
+		IndexOperations documentOperations = operations.indexOps(DynamicFieldDocument.class);
+		documentOperations.createWithMapping();
+
+		DynamicFieldDocument document = new DynamicFieldDocument();
+		document.dynamicFields = Map.of("a_str", randomUUID().toString(), "b_str", randomUUID().toString());
+		operations.save(document);
+
+		// When
+		SearchHits<DynamicFieldDocument> results = operations.search(new StringQuery(MATCH_ALL), DynamicFieldDocument.class);
+
+		// Then
+		assertThat(results.getTotalHits()).isEqualTo(1);
+		documentOperations.delete();
+	}
+
 	// region Entities
 	@Document(indexName = "#{@indexNameProvider.indexName()}")
 	static class Book {
@@ -933,5 +955,14 @@ private static class FieldAliasEntity {
 		@Field(type = Text) private String otherText;
 	}
 
+	@SuppressWarnings("unused")
+	@Document(indexName = "foo")
+	@DynamicTemplates(mappingPath = "/mappings/test-dynamic_templates_mappings_three.json")
+	private static class DynamicFieldDocument {
+		@Nullable
+		@Id String id;
+
+		@Field(name = "*_str", dynamicTemplate = true) private Map<String, String> dynamicFields = new HashMap<>();
+	}
 	// endregion
 }

src/test/resources/mappings/test-dynamic_templates_mappings_three.json

@@ -0,0 +1,12 @@
+{
+  "dynamic_templates": [
+    {
+      "_str": {
+        "match": "*_str",
+        "mapping": {
+          "type": "keyword"
+        }
+      }
+    }
+  ]
+}