rocketmq异步发送消息报超时或者The producer service state not OK, SHUTDOWN_ALREADY

报错内容
异步回调需要时间，设置发送消息的超时时间关闭producer之前等待几秒
async_Producer.setSendMsgTimeout(15000);
countDownLatch.await(8, TimeUnit.SECONDS);

/**
 * @Author: wty
 * @ Data: 2023/4/6 16:07
 */
public class AsyncProducer {

    public static void main(String[] args) throws MQClientException, InterruptedException {
        //1.创建生产者，指定group
        DefaultMQProducer async_Producer = new DefaultMQProducer("my-producer-group");
        //2.指定nameserver的地址
        async_Producer.setNamesrvAddr("127.0.0.1:9876");
        //设置信息发送超时时间
        async_Producer.setSendMsgTimeout(15000);
        //启动
        async_Producer.start();
        //当异步消息发送失败了要重试几次
        async_Producer.setRetryTimesWhenSendAsyncFailed(0);
        int messgeCount = 100;
        final CountDownLatch countDownLatch = new CountDownLatch(messgeCount);
        for (int i = 0; i < messgeCount; i++) {
            try {
                final int index = i;
                Message message = new Message("MyTopic1", "TagA", ("你好" + i).getBytes());
                async_Producer.send(message, new SendCallback() {
                    public void onSuccess(SendResult sendResult) {
                        countDownLatch.countDown();
                        System.out.printf("%-10d ok %s %n",index,sendResult.getMsgId());
                    }

                    public void onException(Throwable e) {
                        countDownLatch.countDown();
                        System.out.printf("%-10d exception %s %n", index, e);
                        e.printStackTrace();
                    }
                });
            } catch (RemotingException e) {
                e.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("==============");
        //等待8秒
        countDownLatch.await(8, TimeUnit.SECONDS);
        async_Producer.shutdown();
    }

}