RocketMQ部署和使用

好久沒有更新博客了，這次講講RocketMQ的部署和使用。
http://rocketmq.apache.org/
首先去下載源碼，網站上有說明RocketMQ的部署環境：
1、64bit OS, Linux/Unix/Mac is recommended;
2、64bit JDK 1.8+;
3、Maven 3.2.x
4、Git
這裏的Git可有可無（用於Git工具從GitHub下載RocketMQ源碼），如果沒有也可以直接去上面的地址下載RocketMQ源碼。
下載完成以後，根據 http://rocketmq.apache.org/docs/quick-start/ 的步驟完成解壓、編譯、運行。
待到Name Server和Broker都跑起來，就可以運行Java代碼測試功能了。

MQProducer

package MQProducer;

import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;

public class Producer {
    public static void main(String[] args){
        DefaultMQProducer producer = new DefaultMQProducer("Producer");
        producer.setNamesrvAddr("127.0.0.1:9876");
        try {
            producer.start();

            Message msg = new Message("PushTopic",
                    "push",
                    "1",
                    "Just for test.".getBytes());

            SendResult result = producer.send(msg);
            System.out.println("id:" + result.getMsgId() +
                    " result:" + result.getSendStatus());

            msg = new Message("PushTopic",
                    "push",
                    "2",
                    "Just for test.".getBytes());

            result = producer.send(msg);
            System.out.println("id:" + result.getMsgId() +
                    " result:" + result.getSendStatus());

            msg = new Message("PullTopic",
                    "pull",
                    "1",
                    "Just for test.".getBytes());

            result = producer.send(msg);
            System.out.println("id:" + result.getMsgId() +
                    " result:" + result.getSendStatus());
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            producer.shutdown();
        }
    }
}

MQConsumer

package MQConsumer;

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.common.consumer.ConsumeFromWhere;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.common.message.MessageExt;

import java.util.List;

public class Consumer {
    public static void main(String[] args){
        DefaultMQPushConsumer consumer =
                new DefaultMQPushConsumer("PushConsumer");
        consumer.setNamesrvAddr("127.0.0.1:9876");
        try {
            //訂閱PushTopic下Tag爲push的消息
            consumer.subscribe("PushTopic", "push");
            //程序第一次啓動從消息隊列頭取數據
            consumer.setConsumeFromWhere(
                    ConsumeFromWhere.CONSUME_FROM_FIRST_OFFSET);
            consumer.registerMessageListener(
                    new MessageListenerConcurrently() {
                        public ConsumeConcurrentlyStatus consumeMessage(
                                List<MessageExt> list,
                                ConsumeConcurrentlyContext Context) {
                            Message msg = list.get(0);
                            System.out.println(msg.toString());
                            return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
                        }
                    }
            );
            consumer.start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
RocketMQ訂閱是根據Topic的信息來的，所以這裏只能收到PushTopic的消息，而收不到PullTopic的。

注意：下列jar包一個都不能少。

fastjson-1.2.44.jar
netty-all-4.1.19.Final.jar
rocketmq-client-4.2.0.jar
rocketmq-common-4.2.0.jar
rocketmq-remoting-4.2.0.jar
slf4j-api-1.7.25.jar
slf4j-nop-1.7.25.jar

slf4j是RocketMQ記錄日誌的。fastjson也是必要的，如果沒有這個jar包，可能會出現找不到路由的錯誤。

java -version

java version "1.8.0_152"
Java(TM) SE Runtime Environment (build 1.8.0_152-b16)
Java HotSpot(TM) 64-Bit Server VM (build 25.152-b16, mixed mode)

mvn -v

Apache Maven 3.5.2

RocketMQ version

4.2.0

最後，開啓RocketMQ，跑代碼