Add excludeFromSource handling to multifield.

Original Pull Request #2975
Closes #2971

(cherry picked from commit 555b570)

Author: sothawo

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

@@ -345,8 +345,10 @@ private void buildPropertyMapping(ObjectNode propertiesNode, boolean isRootObjec
 					: nestedPropertyPrefix + '.' + property.getFieldName();
 
 			Field fieldAnnotation = property.findAnnotation(Field.class);
+			MultiField multiFieldAnnotation = property.findAnnotation(MultiField.class);
 
-			if (fieldAnnotation != null && fieldAnnotation.excludeFromSource()) {
+			if ((fieldAnnotation != null && fieldAnnotation.excludeFromSource()) ||
+					multiFieldAnnotation != null && multiFieldAnnotation.mainField().excludeFromSource()) {
 				excludeFromSource.add(nestedPropertyPath);
 			}
 
@@ -377,17 +379,15 @@ private void buildPropertyMapping(ObjectNode propertiesNode, boolean isRootObjec
 				}
 			}
 
-			MultiField multiField = property.findAnnotation(MultiField.class);
-
 			if (isCompletionProperty) {
 				CompletionField completionField = property.findAnnotation(CompletionField.class);
 				applyCompletionFieldMapping(propertiesNode, property, completionField);
 			}
 
 			if (isRootObject && fieldAnnotation != null && property.isIdProperty()) {
 				applyDefaultIdFieldMapping(propertiesNode, property);
-			} else if (multiField != null) {
-				addMultiFieldMapping(propertiesNode, property, multiField, isNestedOrObjectProperty, dynamicMapping);
+			} else if (multiFieldAnnotation != null) {
+				addMultiFieldMapping(propertiesNode, property, multiFieldAnnotation, isNestedOrObjectProperty, dynamicMapping);
 			} else if (fieldAnnotation != null) {
 				addSingleFieldMapping(propertiesNode, property, fieldAnnotation, isNestedOrObjectProperty, dynamicMapping);
 			}

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

@@ -1090,38 +1090,49 @@ void shouldAddFieldsThatAreExcludedFromSource() throws JSONException {
 
 		String expected = """
 				{
-				  "properties": {
-				    "_class": {
-				      "type": "keyword",
-				      "index": false,
-				      "doc_values": false
-				    },
-				    "excluded-date": {
-				      "type": "date",
-				      "format": "date"
-				    },
-				    "nestedEntity": {
-				      "type": "nested",
-				      "properties": {
-				        "_class": {
-				          "type": "keyword",
-				          "index": false,
-				          "doc_values": false
-				        },
-				        "excluded-text": {
-				          "type": "text"
-				        }
-				      }
-				    }
-				  },
-				  "_source": {
-				    "excludes": [
-				      "excluded-date",
-				      "nestedEntity.excluded-text"
-				    ]
-				  }
-				}
-				"""; //
+                 "properties": {
+                   "_class": {
+                     "type": "keyword",
+                     "index": false,
+                     "doc_values": false
+                   },
+                   "excluded-date": {
+                     "type": "date",
+                     "format": "date"
+                   },
+                   "nestedEntity": {
+                     "type": "nested",
+                     "properties": {
+                       "_class": {
+                         "type": "keyword",
+                         "index": false,
+                         "doc_values": false
+                       },
+                       "excluded-text": {
+                         "type": "text"
+                       }
+                     }
+                   },
+                   "excluded-multifield": {
+                     "type": "text",
+                     "fields": {
+                       "keyword": {
+                         "type": "keyword"
+                       }
+                     }
+                   }
+                 },
+                 "_source": {
+                   "excludes": [
+                     "excluded-date",
+                     "nestedEntity.excluded-text",
+                     "excluded-multifield"
+                   ]
+                 }
+
+				              }
+               
+               """; //
 
 		String mapping = getMappingBuilder().buildPropertyMapping(ExcludedFieldEntity.class);
 
@@ -2395,6 +2406,10 @@ private static class ExcludedFieldEntity {
 				excludeFromSource = true) private LocalDate excludedDate;
 		@Nullable
 		@Field(type = Nested) private NestedExcludedFieldEntity nestedEntity;
+		@Nullable
+		@MultiField(mainField = @Field(name = "excluded-multifield", type = Text, excludeFromSource = true), otherFields = {
+				@InnerField(suffix = "keyword", type = Keyword)
+		}) private String excludedMultifield;
 	}
 
 	@SuppressWarnings("unused")