（二）RocketMq入门之消息发送和接收

一、消息产生、发送

 public class Producer {
 public static void main(String[] args) throws MQClientException {
 　　DefaultMQProducer producer = new DefaultMQProducer("rmq-group");
 　　producer.setNamesrvAddr("172.18.4.114:9876");
 　　producer.setInstanceName("producer");
 　　producer.start();
 　　try {
 　　　　for (int i = ; i < ; i++) {
 　　　　Thread.sleep(); //每5秒发送一次MQ
 　　　　Message msg = new Message("TopicA-test",// topic
 　　　　　　"TagA",// tag
 　　　　　　(new Date() + " Hello RocketMQ ,QuickStart" + i)
 　　　　　　.getBytes()// body
 　　　　　　);
 　　　　SendResult sendResult = producer.send(msg);
 　　　　}
 　　} catch (Exception e) {
 　　　　e.printStackTrace();
 　　}
 　　producer.shutdown();
 　　}
 }

二、消息接收、消费

 import com.alibaba.rocketmq.client.consumer.DefaultMQPushConsumer;
 import com.alibaba.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
 import com.alibaba.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
 import com.alibaba.rocketmq.client.consumer.listener.MessageListenerConcurrently;
 import com.alibaba.rocketmq.client.exception.MQClientException;
 import com.alibaba.rocketmq.common.message.MessageExt;

 import java.util.List;

 public class Consumer {
     public static void main(String[] args) throws MQClientException {
         DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("rmq-group");

         consumer.setNamesrvAddr("172.18.4.114:9876");
         consumer.setInstanceName("consumer");
         consumer.subscribe("TopicA-test", "TagA");

         consumer.registerMessageListener(new MessageListenerConcurrently() {
                 @Override
                 public ConsumeConcurrentlyStatus consumeMessage(
                     List<MessageExt> msgs, ConsumeConcurrentlyContext context) {
                     for (MessageExt msg : msgs) {
                         System.out.println(new String(msg.getTopic()));
                         System.out.println(new String(msg.getTags()));
                         System.out.println("=== " + new String(msg.getBody()));
                     }

                     return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
                 }
             });
         consumer.start();
         System.out.println("Consumer Started.");
     }
 }