RocketMQ中順序消息示例

    本文主要介紹RocketMQ中順序消息的Demo。

一.Producer的代碼

    Producer在發送消息的時候，實現了一個自定義消息隊列選擇器 - MessageQueueSelector，使用消息ID與隊列大小取模，選擇發往的消息隊列：

//Instantiate with a producer group name.
DefaultMQProducer producer = new DefaultMQProducer("example_group_name");
producer.setNamesrvAddr("127.0.0.1:9876");
//Launch the instance.
producer.start();
String[] tags = new String[] {"TagA", "TagB", "TagC", "TagD", "TagE"};
for (int i = 0; i < 100; i++) {
    int orderId = i % 10;
    //Create a message instance, specifying topic, tag and message body.
    Message msg = new Message("TopicTest", tags[i % tags.length], "KEY" + i,
        ("Hello RocketMQ " + i).getBytes());
    SendResult sendResult = producer.send(msg, new MessageQueueSelector() {// 建立一個自定義消息隊列選擇器
        @Override
        public MessageQueue select(List<MessageQueue> mqs, Message msg, Object arg) {
            Integer id = (Integer) arg;
            int index = id % mqs.size();
            return mqs.get(index);
        }
    }, orderId);
    System.out.printf("%s%n", sendResult);
}
//server shutdown
producer.shutdown();

 

二.Consumer的代碼

    Consumer這邊主要使用了一個有序的消息監聽器 - MessageListenerOrderly：

DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("example_group_name");
consumer.setNamesrvAddr("127.0.0.1:9876");
consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_FIRST_OFFSET);
consumer.subscribe("TopicTest", "TagA || TagC || TagD");
consumer.registerMessageListener(new MessageListenerOrderly() {
    AtomicLong consumeTimes = new AtomicLong(0);
    @Override
    public ConsumeOrderlyStatus consumeMessage(List<MessageExt> msgs,ConsumeOrderlyContext context) {
        Random random = new Random();
        context.setAutoCommit(false);
        System.out.print(Thread.currentThread().getName() + " Receive New Messages: " );
        for (MessageExt msg: msgs) {
            System.out.println("topic=" + msg.getTopic() + ",tags=" + msg.getTags() + ", content:" + new String(msg.getBody()));
        }
        return ConsumeOrderlyStatus.SUCCESS;
    }
});
consumer.start();
System.out.printf("Consumer Started.%n");

 

三.輸出結果

    Producer輸出：

SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2990000, offsetMsgId=C0A81FA100002A9F00000000001730CB, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=0], queueOffset=1900]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2B00001, offsetMsgId=C0A81FA100002A9F0000000000173187, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=1], queueOffset=1900]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2B30002, offsetMsgId=C0A81FA100002A9F0000000000173243, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=2], queueOffset=1850]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2B80003, offsetMsgId=C0A81FA100002A9F00000000001732FF, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=3], queueOffset=1850]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2BA0004, offsetMsgId=C0A81FA100002A9F00000000001733BB, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=0], queueOffset=1901]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2BE0005, offsetMsgId=C0A81FA100002A9F0000000000173477, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=1], queueOffset=1901]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2C10006, offsetMsgId=C0A81FA100002A9F0000000000173533, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=2], queueOffset=1851]
SendResult [sendStatus=SEND_OK, msgId=C0A81FA13B1418B4AAC24B92A2C30007, offsetMsgId=C0A81FA100002A9F00000000001735EF, messageQueue=MessageQueue [topic=TopicTest, brokerName=DESKTOP-SH1N0UM, queueId=3], queueOffset=1851]

 

    Consumer輸出：消費端建立了不少線程消費，可是從不一樣ag來看都是有序的。

ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagA, content:Hello RocketMQ 40 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagD, content:Hello RocketMQ 48 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagA, content:Hello RocketMQ 50 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagD, content:Hello RocketMQ 58 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagA, content:Hello RocketMQ 60 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagD, content:Hello RocketMQ 68 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagA, content:Hello RocketMQ 70 
ConsumeMessageThread_20 Receive New Messages: topic=TopicTest,tags=TagD, content:Hello RocketMQ 78

 

    本文主要介紹了順序消息的發送和接收，下一篇文章，將分析RocketMQ是如何能保證消息有序發送和接收的。