final RemotingCommand response = RemotingCommand.createResponseCommand(null);
Set<String> topics = this.brokerController.getTopicConfigManager().getSystemTopic();
TopicList topicList = new TopicList();
topicList.setTopicList(topics);
response.setBody(topicList.encode());
response.setCode(ResponseCode.SUCCESS);
response.setRemark(null);
return response;
}