<!-- in your <dependencies> block -->
  <dependency>
      <groupId>org.apache.rocketmq</groupId>
      <artifactId>rocketmq-client</artifactId>
      <version>4.9.4</version>
  </dependency>
  
  <dependency>
      <groupId>org.apache.rocketmq</groupId>
      <artifactId>rocketmq-acl</artifactId>
      <version>4.9.4</version>
  </dependency>

// Instantiate a message producer.
   DefaultMQProducer producer = new DefaultMQProducer(
       groupName,
       new AclClientRPCHook(new SessionCredentials(accessKey, secretKey)) // ACL permissions.
   );
   // Set the NameServer address.
   producer.setNamesrvAddr(nameserver);
   // Start the producer instance.
   producer.start();


for (int i = 0; i < 10; i++) {
          // Create a message instance and set the topic and message content.
          Message msg = new Message(topic_name, "TAG", ("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
          // Send messages.
          SendResult sendResult = producer.send(msg);
          System.out.printf("%s%n", sendResult);
      }

// Disable retries on message sending failure.
      producer.setRetryTimesWhenSendAsyncFailed(0);
      // Set the number of messages to send.
      int messageCount = 10;
      final CountDownLatch countDownLatch = new CountDownLatch(messageCount);
      for (int i = 0; i < messageCount; i++) {
          try {
              final int index = i;
              // Create a message instance and set the topic and message content.
              Message msg = new Message(topic_name, "TAG", ("Hello rocketMq " + index).getBytes(RemotingHelper.DEFAULT_CHARSET));
              producer.send(msg, new SendCallback() {
                  @Override
                  public void onSuccess(SendResult sendResult) {
                      // Logic for successful message sending.
                      countDownLatch.countDown();
                      System.out.printf("%-10d OK %s %n", index, sendResult.getMsgId());
                  }
      
                  @Override
                  public void onException(Throwable e) {
                      // Logic for failed message sending.
                      countDownLatch.countDown();
                      System.out.printf("%-10d Exception %s %n", index, e);
                      e.printStackTrace();
                  }
              });
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
      countDownLatch.await(5, TimeUnit.SECONDS);

for (int i = 0; i < 10; i++) {
         // Create a message instance and set the topic and message content.
         Message msg = new Message(topic_name, "TAG", ("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
         // Send a one-way message.
         producer.sendOneway(msg);
     }

// Instantiate a consumer.
        DefaultMQPushConsumer pushConsumer = new DefaultMQPushConsumer(
            groupName,                                              
            new AclClientRPCHook(new SessionCredentials(accessKey, secretKey))); // ACL permissions.
        // Set the NameServer address.
        pushConsumer.setNamesrvAddr(nameserver);

// Subscribe to a topic.
      pushConsumer.subscribe(topic_name, "*");
      // Register a callback implementation class to handle messages pulled from the broker.
      pushConsumer.registerMessageListener((MessageListenerConcurrently) (msgs, context) -> {
          // Message processing logic.
          System.out.printf("%s Receive New Messages: %s %n", Thread.currentThread().getName(), msgs);
          // Mark the message as successfully consumed and return an appropriate status.
          return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
      });
      // Start the consumer instance.
      pushConsumer.start();