rocketmq发送消息报错——not exist, apply first please

确定broker连上了nameserver，消费者没连上nameserver，请问如何解决 报错信息——

org.apache.rocketmq.client.exception.MQBrokerException: CODE: 17  DESC: topic[order-group] not exist, apply first please!

消费者设置

DefaultMQProducer producer = new DefaultMQProducer("order-group");
        producer.setNamesrvAddr("127.0.0.1:9876");
        producer.setCreateTopicKey("order-topic");
        producer.setSendMessageWithVIPChannel(false);
        producer.setInstanceName(System.currentTimeMillis()+"");
        producer.start();
        System.out.println(producer.getCreateTopicKey());