Caused by: java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'topicController' method org.oracleone.forohub.controller.TopicController#deleteTopic(Long) to {DELETE [/api/topics/{id}]}: There is already 'topicController' bean method org.oracleone.forohub.controller.TopicController#deleteTopicById(Long) mapped.

so try to remove one ambiguous mapping in your TopicController