使用 4.0 SDK 收发普通消息

<!-- in your <dependencies> block -->
  <dependency>
      <groupId>org.apache.rocketmq</groupId>
      <artifactId>rocketmq-client</artifactId>
      <version>4.9.7</version>
  </dependency>
  
  <dependency>
      <groupId>org.apache.rocketmq</groupId>
      <artifactId>rocketmq-acl</artifactId>
      <version>4.9.7</version>
  </dependency>

// 实例化消息生产者Producer
   DefaultMQProducer producer = new DefaultMQProducer(
       groupName,
       new AclClientRPCHook(new SessionCredentials(accessKey, secretKey)) // ACL权限
   );
   // 设置NameServer的地址,地址就是形如xxx.tencenttdmq.com:8080 这样的接入地址。
   producer.setNamesrvAddr(nameserver);
   // 启动Producer实例
   producer.start();
   
   for (int i = 0; i < 10; i++) {
          // 创建消息实例，设置topic和消息内容.
          Message msg = new Message(topic_name, ("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
          // 发送消息
          SendResult sendResult = producer.send(msg);
          System.out.printf("%s%n", sendResult);
   }

// 实例化消费者
DefaultMQPushConsumer pushConsumer = new DefaultMQPushConsumer(
            groupName,                                              
            new AclClientRPCHook(new SessionCredentials(accessKey, secretKey))); //ACL权限
        // 设置NameServer的地址
pushConsumer.setNamesrvAddr(nameserver);
        // 订阅topic
pushConsumer.subscribe(topic_name, "*");
      // 注册回调实现类来处理从broker拉取回来的消息
pushConsumer.registerMessageListener((MessageListenerConcurrently) (msgs, context) -> {
          // 消息处理逻辑
          System.out.printf("%s Receive New Messages: %s %n", Thread.currentThread().getName(), msgs);
          // 标记该消息已经被成功消费, 根据消费情况，返回处理状态
          return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
      });
      // 启动消费者实例
pushConsumer.start();