get generator from the factory based on the annotation type name

Author: SaifJerbi

src/main/java/io/asfjava/ui/core/schema/UiFormSchemaGenerator.java

@@ -45,7 +45,7 @@ private void buildFormDefinition(ObjectMapper mapper, ArrayNode formDefinition,
 	private JsonNode buildFieldDefinition(Field field, Annotation annotation, ObjectMapper mapper) {
 		ObjectNode fieldFormDefinition = mapper.createObjectNode();
 		FormDefinitionGenerator generator = FormDefinitionGeneratorFactory.getInstance()
-				.getGenerator(annotation.getClass().getName());
+				.getGenerator(annotation.annotationType().getName());
 		generator.generate(fieldFormDefinition, field);
 		return fieldFormDefinition;