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关于java:使用RocketMQ消费消息

RocketMQ 生产端

明天要来跟大家学习怎么应用 RocketMQ 来进行音讯的生产

先简略创立个 Maven 我的项目应用

  • 增加依赖
<dependency>
    <groupId>org.apache.rocketmq</groupId>
    <artifactId>rocketmq-client</artifactId>
    <version>4.9.2</version>
</dependency>
  • 启动消费者

    package mq.consumer;
    
    import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
    import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
    import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
    import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
    import org.apache.rocketmq.client.exception.MQClientException;
    import org.apache.rocketmq.common.message.MessageExt;
    import org.apache.rocketmq.common.protocol.heartbeat.MessageModel;
    
    import java.util.List;
    
    public class BroadcastConsumer {public static void main(String[] args) throws MQClientException {
            // 创立一个 push 模式的生产组
            DefaultMQPushConsumer pushConsumer = new DefaultMQPushConsumer("pushConsumer");
            pushConsumer.setNamesrvAddr("localhost:9876");
            // 集群模式
            pushConsumer.setMessageModel(MessageModel.CLUSTERING);
            //  订阅的 topic tag
            pushConsumer.subscribe("topic_test01","Tag1 || Tag2");
    
            pushConsumer.registerMessageListener(new MessageListenerConcurrently() {
                @Override
                public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {System.out.printf(Thread.currentThread().getName() + "Receive New Messages:" + msgs + "%n");
                    return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
                }
            });
            pushConsumer.start();
            System.out.printf("Broadcast Consumer Started.%n");
    
        }
    
  • 启动生产者

    package mq.producer;
    
    import org.apache.rocketmq.client.exception.MQBrokerException;
    import org.apache.rocketmq.client.exception.MQClientException;
    import org.apache.rocketmq.client.producer.DefaultMQProducer;
    import org.apache.rocketmq.client.producer.SendResult;
    import org.apache.rocketmq.common.message.Message;
    import org.apache.rocketmq.remoting.common.RemotingHelper;
    import org.apache.rocketmq.remoting.exception.RemotingException;
    
    import java.io.UnsupportedEncodingException;
    
    public class SyncProducerV2 {
        /**
         * 同步音讯发送
         *
         * @param args
         * @throws MQClientException
         * @throws MQBrokerException
         * @throws RemotingException
         * @throws InterruptedException
         * @throws UnsupportedEncodingException
         */
        public static void main(String[] args) throws MQClientException, MQBrokerException, RemotingException, InterruptedException, UnsupportedEncodingException {System.out.println("SyncProducer start......");
            DefaultMQProducer defaultMQProducer = new DefaultMQProducer("pg_sync_01");
            defaultMQProducer.setNamesrvAddr("localhost:9876");
            defaultMQProducer.start();
            for (int i = 0; i < 10; i++) {send(defaultMQProducer, i, i % 3);
            }
            defaultMQProducer.shutdown();
            System.out.println("SyncProducer end......");
    
        }
    
        private static void send(DefaultMQProducer defaultMQProducer, Integer i, int tag) throws MQClientException, RemotingException, MQBrokerException, InterruptedException, UnsupportedEncodingException {SendResult sendResult = defaultMQProducer.send(new Message("topic_test01", "Tag" + tag, ("hello this is sync message_" + i + "!").getBytes(RemotingHelper.DEFAULT_CHARSET)));
            System.out.println(sendResult);
        }
    }
  • 消费者生产

能够看到生产了 Tag 为 Tag1、Tag2 的音讯

其它 Tag 会被过滤掉

生产分类

RocketMQ 的生产模式分为两种:BROADCASTING(播送)和CLUSTERING(集群)

那这两种模式有什么区别呢?

  • 播送:雷同生产组下的实例会反复生产同一个 Topic 的音讯,能够了解为大家做同样的工作,生产进度存储在客户端,有可能会导致局部音讯没有被生产
  • 集群:雷同生产组下的实例会负载平衡地生产同一个 Topic 的音讯,能够了解为分工合作,生产进度存储在 Broker 端

所以大部分零碎都会应用集群模式去生产信息,毕竟能够程度拓展消费者来接受更大的生产压力

播送模式相对来说应用比拟少,个别都是一些音讯告诉同步的场景,想同步刷新缓存等

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