RocketMQ-消息发送.jpeg

运行NameServer和Broker后，我们可以尝试用代码示例写一下：消息发送的三种方式

• 同步发送，适用场景：对可靠性高的业务场景
• 异步发送，适用场景：对响应时间比较敏感的业务场景，就是不允许长时间等待结果的场景
• 发送一次，适用场景：不关心发送结果场景。比如日志发送

依赖

<dependency>
    <groupId>org.apache.rocketmq</groupId>
    <artifactId>rocketmq-client</artifactId>
    <version>4.8.0</version>
</dependency>

同步发送

public class SyncProducer {
    public static void main(String[] args) throws MQClientException, UnsupportedEncodingException, RemotingException, InterruptedException, MQBrokerException {
        DefaultMQProducer defaultMQProducer = new DefaultMQProducer();
        //设置生产者组
        defaultMQProducer.setProducerGroup("syncProducer");

        //设置nameserver
        defaultMQProducer.setNamesrvAddr("localhost:9876");

        //启动生产者
        defaultMQProducer.start();

        for (int i = 0; i < 10; i++) {
            //构建消息 topic tag 内容
            Message msg = new Message("TopicTest" /* Topic */,
                    "TagA" /* Tag */,
                    ("Hello RocketMQ " +
                            i).getBytes(RemotingHelper.DEFAULT_CHARSET) /* Message body */
            );
            //同步发送，且返回结果
            SendResult sendResult = defaultMQProducer.send(msg);
            System.out.println("发送结果"+sendResult);
        }
        //关闭生产者
        defaultMQProducer.shutdown();
    }
}
//运行结果
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2040000, offsetMsgId=C0A81FF100002A9F0000000000045402, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=1], queueOffset=350]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2230001, offsetMsgId=C0A81FF100002A9F00000000000454CB, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=2], queueOffset=350]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2260002, offsetMsgId=C0A81FF100002A9F0000000000045594, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=3], queueOffset=350]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E22A0003, offsetMsgId=C0A81FF100002A9F000000000004565D, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=0], queueOffset=350]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E22C0004, offsetMsgId=C0A81FF100002A9F0000000000045726, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=1], queueOffset=351]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E22E0005, offsetMsgId=C0A81FF100002A9F00000000000457EF, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=2], queueOffset=351]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2300006, offsetMsgId=C0A81FF100002A9F00000000000458B8, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=3], queueOffset=351]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2320007, offsetMsgId=C0A81FF100002A9F0000000000045981, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=0], queueOffset=351]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2340008, offsetMsgId=C0A81FF100002A9F0000000000045A4A, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=1], queueOffset=352]
发送结果SendResult [sendStatus=SEND_OK, msgId=7F000001503218B4AAC29874E2360009, offsetMsgId=C0A81FF100002A9F0000000000045B13, messageQueue=MessageQueue [topic=TopicTest, brokerName=aarondeMBP, queueId=2], queueOffset=352]
14:29:56.930 [NettyClientSelector_1] INFO RocketmqRemoting - closeChannel: close the connection to remote address[127.0.0.1:9876] result: true
14:29:56.932 [NettyClientSelector_1] INFO RocketmqRemoting - closeChannel: close the connection to remote address[127.0.0.1:9876] result: true
14:29:56.932 [NettyClientSelector_1] INFO RocketmqRemoting - closeChannel: close the connection to remote address[192.168.31.241:10911] result: true

异步发送

public class AsyncProducer {
    public static void main(String[] args) throws Exception {
        //设置生产者名字
        DefaultMQProducer producer = new DefaultMQProducer("asyncproducer");
        // 设置nameserver的地址
        producer.setNamesrvAddr("localhost:9876");
        //生产者启动
        producer.start();
        //发送失败重试次数
        producer.setRetryTimesWhenSendAsyncFailed(0);
        
        int messageCount = 10;
        for (int i = 0; i < messageCount; i++) {
            try {
                final int index = i;
                Message msg = new Message("async_topic",
                    "TagA",
                    "OrderID188",
                    "Hello world".getBytes(RemotingHelper.DEFAULT_CHARSET));
                //异步发送，这里多了一个SendCallBack回调函数
                producer.send(msg, new SendCallback() {
                    //发送成功
                    @Override
                    public void onSuccess(SendResult sendResult) {
                        System.out.println("发送成功:"+sendResult);
                    }
                    //发送失败
                    @Override
                    public void onException(Throwable e) {
                        System.out.printf("发送失败:"+e);
                        e.printStackTrace();
                    }
                });
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        TimeUnit.SECONDS.sleep(3);
        producer.shutdown();
    }
}
//运行结果
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868BF40001, offsetMsgId=C0A81FF100002A9F0000000000046438, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=3], queueOffset=2]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C1A0004, offsetMsgId=C0A81FF100002A9F0000000000046790, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=0], queueOffset=1]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868BFA0002, offsetMsgId=C0A81FF100002A9F000000000004650E, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=3], queueOffset=3]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C0B0003, offsetMsgId=C0A81FF100002A9F00000000000466BA, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=2], queueOffset=5]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868BF10000, offsetMsgId=C0A81FF100002A9F00000000000465E4, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=1], queueOffset=2]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C1C0005, offsetMsgId=C0A81FF100002A9F0000000000046866, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=0], queueOffset=2]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C1C0006, offsetMsgId=C0A81FF100002A9F000000000004693C, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=0], queueOffset=3]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C280007, offsetMsgId=C0A81FF100002A9F0000000000046A12, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=1], queueOffset=3]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C2D0008, offsetMsgId=C0A81FF100002A9F0000000000046AE8, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=1], queueOffset=4]
发送成功:SendResult [sendStatus=SEND_OK, msgId=7F000001514218B4AAC298868C330009, offsetMsgId=C0A81FF100002A9F0000000000046BBE, messageQueue=MessageQueue [topic=async_topic, brokerName=aarondeMBP, queueId=0], queueOffset=4]
14:49:17.262 [NettyClientSelector_1] INFO RocketmqRemoting - closeChannel: close the connection to remote address[127.0.0.1:9876] result: true
14:49:17.265 [NettyClientSelector_1] INFO RocketmqRemoting - closeChannel: close the connection to remote address[127.0.0.1:9876] result: true
14:49:17.265 [NettyClientSelector_1] INFO RocketmqRemoting - closeChannel: close the connection to remote address[192.168.31.241:10911] result: true

发送一次

public class OnewayProducer {
    public static void main(String[] args) throws Exception{
        //初始化生产者
        DefaultMQProducer producer = new DefaultMQProducer("onewayproducer");
        // 置顶nameserver名字
        producer.setNamesrvAddr("localhost:9876");
        //启动生产者
        producer.start();
        for (int i = 0; i < 10; i++) {
            //构建消息体
            Message msg = new Message("oneway_topic" /* Topic */,
                "TagA" /* Tag */,
                ("Hello RocketMQ " +
                    i).getBytes(RemotingHelper.DEFAULT_CHARSET) /* Message body */
            );
            //发送一次性消息
            producer.sendOneway(msg);
        }

        Thread.sleep(5000);        
        producer.shutdown();
    }
}

同步发送，异步发送，一次性发送是RocketMQ主要的三种消息发送方式。

来一个拓展：类似的Kafka和RabbitMQ有哪些消息发送方式，欢迎留言回答。

工作中，具体用什么发送方式，得取决你的业务场景。需要可靠性的，就用同步发送。需要低延时的，就用异步发送，如果压根不care发送结果，直接用一次性发送。

后续文章

• RocketMQ-入门(已更新)
• RocketMQ-消息发送(已更新)
• RocketMQ-消费信息
• RocketMQ-消费者的广播模式和集群模式
• RocketMQ-顺序消息
• RocketMQ-延迟消息
• RocketMQ-批量消息
• RocketMQ-过滤消息
• RocketMQ-事务消息
• RocketMQ-消息存储
• RocketMQ-高可用
• RocketMQ-高性能
• RocketMQ-主从复制
• RocketMQ-刷盘机制
• RocketMQ-幂等性
• RocketMQ-消息重试
• RocketMQ-死信队列
  ...

欢迎各位入(guan)股(zhu)，后续文章干货多多。