RocketMQ(一) 生产者和消费者完整示例

生产者和消费者，发消息和接收消息，完整示例

RocketMQ是阿里巴巴在2012年开源的分布式消息中间件，目前已经捐赠给Apache基金会，已经于2016年11月成为 Apache 孵化项目，相信RocketMQ的未来会发挥着越来越大的作用，将有更多的开发者因此受益。

本文仅对RocketMQ的简单实用做入门性介绍，不对RocketMQ的底层原理进行深入介绍，后续文章将对RocketMQ的原理做详细介绍。

一、添加RocketMQ的Maven依赖：

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<dependency>
<groupId>com.alibaba.rocketmq</groupId>
<artifactId>rocketmq-client</artifactId>
<version>3.2.6</version>
</dependency>

二、 MQ的消费类RocketMQConsumer.java：

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package com.lance.rocketMQ.RocketMQ;
import com.alibaba.rocketmq.client.consumer.DefaultMQPushConsumer;
import com.alibaba.rocketmq.client.consumer.listener.MessageListener;
import com.alibaba.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import com.alibaba.rocketmq.client.exception.MQClientException;
import com.alibaba.rocketmq.common.consumer.ConsumeFromWhere;
import java.util.UUID;
/**
* 消费类
*/
public class RocketMQConsumer {
private DefaultMQPushConsumer consumer;
private MessageListener listener;
protected String nameServer;
protected String groupName;
protected String topics;
public RocketMQConsumer(MessageListener listener, String nameServer, String groupName, String topics) {
this.listener = listener;
this.nameServer = nameServer;
this.groupName = groupName;
this.topics = topics;
}
/**
* 初始化方法
*/
public void init() {
consumer = new DefaultMQPushConsumer(groupName);
consumer.setNamesrvAddr(nameServer);
try {
consumer.subscribe(topics, "*"); //topic 与tag 生产者未设置tag,消费者可将tag设置为*
} catch (MQClientException e) {
e.printStackTrace();
}
consumer.setInstanceName(UUID.randomUUID().toString());
consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_LAST_OFFSET);
consumer.registerMessageListener((MessageListenerConcurrently) this.listener);
try {
consumer.start(); //启动消费者
} catch (MQClientException e) {
e.printStackTrace();
}
System.out.println("RocketMQConsumer Started! group=" + consumer.getConsumerGroup() + " instance=" + consumer.getInstanceName()
);
}
}

三、MQ消息的监听接口类RocketMQListener.java

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package com.lance.rocketMQ.RocketMQ;
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.common.message.MessageExt;
import java.util.List;
/**
* 消费监听类
*/
public class RocketMQListener implements MessageListenerConcurrently {
@Override
public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {
// System.out.println("get data from rocketMQ:" + msgs);
for (MessageExt message : msgs) {
String msg = new String(message.getBody()); //从mq中取得消息
System.out.println("msg data from rocketMQ:" + msg);
}
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS; //消费成功，返回消息失败：RECONSUME_LATER
}
}

四、 MQ消息的生产者类RocketMQProducer.java

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package com.lance.rocketMQ.RocketMQ;
import com.alibaba.rocketmq.client.exception.MQClientException;
import com.alibaba.rocketmq.client.producer.DefaultMQProducer;
import com.alibaba.rocketmq.client.producer.SendResult;
import com.alibaba.rocketmq.client.producer.SendStatus;
import com.alibaba.rocketmq.common.message.Message;
import java.util.UUID;
/**
* 生产者
*/
public class RocketMQProducer {
private DefaultMQProducer sender;
protected String nameServer;
protected String groupName;
protected String topics;
//初始化生产者
public void init() {
sender = new DefaultMQProducer(groupName);
sender.setNamesrvAddr(nameServer);
sender.setInstanceName(UUID.randomUUID().toString());
try {
sender.start(); //启动生产者
} catch (MQClientException e) {
e.printStackTrace();
}
}
public RocketMQProducer(String nameServer, String groupName, String topics) {
this.nameServer = nameServer;
this.groupName = groupName;
this.topics = topics;
}
//发送消息
public void send(Message message) {
message.setTopic(topics);
try {
SendResult result = sender.send(message);
SendStatus status = result.getSendStatus();
System.out.println("messageId=" + result.getMsgId() + ", status=" + status);
} catch (Exception e) {
e.printStackTrace();
}
}
}

五、测试RocketMQ的消费 RocketMQConsumerTest.java

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package com.lance.rocketMQ.RocketMQ;
/**
* 测试消费者
*/
public class RocketMQConsumerTest {
public static void main(String[] args) {
String mqNameServer = "172.10.254.2:9876"; //注册地址
String mqTopics = "MQ-MSG-TOPICS-TEST"; //主题
String consumerMqGroupName = "CONSUMER-MQ-GROUP"; //消费组
RocketMQListener mqListener = new RocketMQListener();
RocketMQConsumer mqConsumer = new RocketMQConsumer(mqListener, mqNameServer, consumerMqGroupName, mqTopics);
mqConsumer.init(); //调用消费者
try {
Thread.sleep(1000 * 60L);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

run RocketMQConsumerTest.java 之后，控制台输出：

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RocketMQConsumer Started! group=CONSUMER-MQ-GROUP instance=1eb7d308-4414-4658-90b5-e2cae3b793eb

结果分析：此时MQ对应的TOPIC中并没有响应的消息，故收不到消息，仅看到MQ消费者正常启动信息。

六、MQ的生产者测试类:RocketMQProducerTest.java

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package com.lance.rocketMQ.RocketMQ;
import com.alibaba.rocketmq.common.message.Message;
/**
* 生产者测试
*/
public class RocketMQProducerTest {
public static void main(String[] args) {
String mqNameServer = "172.10.254.2:9876"; //生产者注册地址
String mqTopics = "MQ-MSG-TOPICS-TEST"; //主题
String producerMqGroupName = "PRODUCER-MQ-GROUP"; //生产者group
RocketMQProducer mqProducer = new RocketMQProducer(mqNameServer, producerMqGroupName, mqTopics);
mqProducer.init();
for (int i = 0; i < 5; i++) {
Message message = new Message();
message.setBody(("I send message to RocketMQ " + i).getBytes());
mqProducer.send(message); //发送消息
}
}
}

run RocketMQProducerTest.java 之后，RocketMQProducerTest.java 对应的控制台输出为：

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messageId=0A71290100002A9F00000003D0BB0832, status=SEND_OK
messageId=0A71290100002A9F00000003D0BB08BB, status=SEND_OK
messageId=0A71290100002A9F00000003D0BB0944, status=SEND_OK
messageId=0A71290100002A9F00000003D0BB09CD, status=SEND_OK
messageId=0A71290300002A9F000000005440AEED, status=SEND_OK

结果分析：表明所有消息都已经正常发送，且被RocketMQ正常接收。

此时查看RocketMQConsumerTest.java对应的控制台输出发生改变，输出内容变更如下:

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RocketMQConsumer Started! group=CONSUMER-MQ-GROUP instance=1eb7d308-4414-4658-90b5-e2cae3b793eb
msg data from rocketMQ:I send message to RocketMQ 1
msg data from rocketMQ:I send message to RocketMQ 0
msg data from rocketMQ:I send message to RocketMQ 3
msg data from rocketMQ:I send message to RocketMQ 2
msg data from rocketMQ:I send message to RocketMQ 4

RocketMQ(一) 生产者和消费者完整示例

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