code: protected String getMappedFieldName(String fieldName, @Nullable Class<?> domainType) {
  
  		if (domainType == null || mappingContext == null) {
  			return fieldName;
  		}
  
  		SolrPersistentEntity entity = mappingContext.getPersistentEntity(domainType);
  		if (entity == null) {
  			return fieldName;
  		}
  
  		SolrPersistentProperty property = entity.getPersistentProperty(fieldName);
  		return property != null ? property.getFieldName() : fieldName;
  	}
docs: Get the mapped field name using meta information derived from the given domain type.
  
  @param fieldName
  @param domainType
  @return
  @since 4.0