Fix recative mapping creation.

Original Pull Request #1821

Author: sothawo

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

@@ -210,6 +210,7 @@ protected Document buildMapping(Class<?> clazz) {
 
 		// load mapping specified in Mapping annotation if present
 		Mapping mappingAnnotation = AnnotatedElementUtils.findMergedAnnotation(clazz, Mapping.class);
+
 		if (mappingAnnotation != null) {
 			String mappingPath = mappingAnnotation.mappingPath();
 

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

@@ -183,7 +183,11 @@ public Mono<Document> createMapping(Class<?> clazz) {
 		Mapping mappingAnnotation = AnnotatedElementUtils.findMergedAnnotation(clazz, Mapping.class);
 
 		if (mappingAnnotation != null) {
-			return loadDocument(mappingAnnotation.mappingPath(), "@Mapping");
+			String mappingPath = mappingAnnotation.mappingPath();
+
+			if (hasText(mappingPath)) {
+				return loadDocument(mappingAnnotation.mappingPath(), "@Mapping");
+			}
 		}
 
 		String mapping = new MappingBuilder(converter).buildPropertyMapping(clazz);