Allow for null and empty parameters in the MultiField annotation.

Signed-off-by: Youssef Aouichaoui <[email protected]>

Author: youssef3wi

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

@@ -98,6 +98,7 @@ public SimpleElasticsearchPersistentProperty(Property property,
 		this.isSeqNoPrimaryTerm = SeqNoPrimaryTerm.class.isAssignableFrom(getRawType());
 
 		boolean isField = isAnnotationPresent(Field.class);
+		boolean isMultiField = isAnnotationPresent(MultiField.class);
 
 		if (isVersionProperty() && !getType().equals(Long.class)) {
 			throw new MappingException(String.format("Version property %s must be of type Long!", property.getName()));
@@ -109,8 +110,10 @@ public SimpleElasticsearchPersistentProperty(Property property,
 
 		initPropertyValueConverter();
 
-		storeNullValue = isField && getRequiredAnnotation(Field.class).storeNullValue();
-		storeEmptyValue = isField ? getRequiredAnnotation(Field.class).storeEmptyValue() : true;
+		storeNullValue = isField ? getRequiredAnnotation(Field.class).storeNullValue()
+				: isMultiField && getRequiredAnnotation(MultiField.class).mainField().storeNullValue();
+		storeEmptyValue = isField ? getRequiredAnnotation(Field.class).storeEmptyValue()
+				: !isMultiField || getRequiredAnnotation(MultiField.class).mainField().storeEmptyValue();
 	}
 
 	@Override

src/test/java/org/springframework/data/elasticsearch/NestedObjectIntegrationTests.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.elasticsearch;
 
+import static co.elastic.clients.elasticsearch._types.query_dsl.QueryBuilders.match;
+import static java.util.UUID.randomUUID;
 import static org.assertj.core.api.Assertions.*;
 import static org.springframework.data.elasticsearch.utils.IdGenerator.*;
 
@@ -28,6 +30,7 @@
 
 import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -37,6 +40,7 @@
 import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.annotations.InnerField;
 import org.springframework.data.elasticsearch.annotations.MultiField;
+import org.springframework.data.elasticsearch.client.elc.NativeQuery;
 import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
 import org.springframework.data.elasticsearch.core.IndexOperations;
 import org.springframework.data.elasticsearch.core.SearchHits;
@@ -373,6 +377,42 @@ public void shouldIndexAndSearchMapAsNestedType() {
 		assertThat(books.getSearchHit(0).getContent().getId()).isEqualTo(book2.getId());
 	}
 
+	@Test // #2952
+	@DisplayName("should handle null and empty field parameters in the mapping process")
+	void shouldSupportMappingNullAndEmptyFieldParameter() {
+		// Given
+		operations.indexOps(MultiFieldWithNullEmptyParameters.class).createWithMapping();
+		List<IndexQuery> indexQueries = new ArrayList<>();
+		MultiFieldWithNullEmptyParameters nullObj = new MultiFieldWithNullEmptyParameters();
+		nullObj.addFieldWithInner(randomUUID().toString());
+		MultiFieldWithNullEmptyParameters objWithValue = new MultiFieldWithNullEmptyParameters();
+		objWithValue.addEmptyField(randomUUID().toString());
+
+		IndexQuery indexQuery1 = new IndexQuery();
+		indexQuery1.setId(nextIdAsString());
+		indexQuery1.setObject(nullObj);
+		indexQueries.add(indexQuery1);
+
+		IndexQuery indexQuery2 = new IndexQuery();
+		indexQuery2.setId(nextIdAsString());
+		indexQuery2.setObject(objWithValue);
+		indexQueries.add(indexQuery2);
+
+		// When
+		operations.bulkIndex(indexQueries, MultiFieldWithNullEmptyParameters.class);
+
+		// Then
+		SearchHits<MultiFieldWithNullEmptyParameters> nullResults = operations.search(
+				NativeQuery.builder().withQuery(match(bm -> bm.field("empty-field").query("EMPTY"))).build(),
+				MultiFieldWithNullEmptyParameters.class);
+		assertThat(nullResults.getSearchHits()).hasSize(1);
+
+		nullResults = operations.search(
+				NativeQuery.builder().withQuery(match(bm -> bm.field("inner-field.prefix").query("EMPTY"))).build(),
+				MultiFieldWithNullEmptyParameters.class);
+		assertThat(nullResults.getSearchHits()).hasSize(1);
+	}
+
 	@NotNull
 	abstract protected Query getNestedQuery4();
 
@@ -622,4 +662,40 @@ public void setName(@Nullable String name) {
 		}
 	}
 
+	@Document(indexName = "#{@indexNameProvider.indexName()}-multi-field")
+	static class MultiFieldWithNullEmptyParameters {
+		@Nullable
+		@MultiField(mainField = @Field(name = "empty-field", type = FieldType.Keyword, nullValue = "EMPTY",
+				storeNullValue = true)) private List<String> emptyField;
+
+		@Nullable
+		@MultiField(mainField = @Field(name = "inner-field", type = FieldType.Text, storeNullValue = true),
+				otherFields = { @InnerField(suffix = "prefix", type = FieldType.Keyword,
+						nullValue = "EMPTY") }) private List<String> fieldWithInner;
+
+		public List<String> getEmptyField() {
+			if (emptyField == null) {
+				emptyField = new ArrayList<>();
+			}
+
+			return emptyField;
+		}
+
+		public void addEmptyField(String value) {
+			getEmptyField().add(value);
+		}
+
+		public List<String> getFieldWithInner() {
+			if (fieldWithInner == null) {
+				fieldWithInner = new ArrayList<>();
+			}
+
+			return fieldWithInner;
+		}
+
+		public void addFieldWithInner(@Nullable String value) {
+			getFieldWithInner().add(value);
+		}
+	}
+
 }