1. 本实例使用的RocketMq版本为4.3.2, JDK>=1.8
2. 启动rocketmq, 在安装目录的bin目录下
启动 NAMESERVER start mqnamesrv.cmd
启动 BROKER start mqbroker.cmd -n 127.0.0.1:9876 autoCreateTopicEnable=true


3. rocketmq jar包
<dependency> <groupId>org.apache.rocketmq</groupId> <artifactId>rocketmq-client</artifactId> <version>4.3.2</version> </dependency>
4. application.properties
# 消费者组名 apache.rocketmq.consumer.PushConsumer=PushConsumer2 # 生产者的组名 apache.rocketmq.producer.producerGroup=Producer4 # NameServer的地址 apache.rocketmq.namesrvAddr=127.0.0.1:9876
Topic 默认对应四个队列 queue, 队列中有生产者和消费者, 生产者组成生产者组, 消费者组成消费组
有相同名称的是属于同一个组的, 一个queue对应一个消费者, 但一个消费者对应多个queue
setConsumeMessageBatchMaxSize ---- 设置批量消费消息的大小 (1: 一次一条 n: 一条多条)
消息消费完成后, 如果消费者返回CONSUME_SUCCESS则消息成功被消费
如果消费者返回RECONSUME_LATER 则消息在一段时间后会被再次消费
produce0 -------> queue0 --------> consume0
ProduceGroup produce1 -------> queue1 --------> consume1 ConsumeGroup
produce2 -------> queue2 --------> consume2
produce3 -------> queue3 --------> consume3
5. 生产者代码
@Component
public class RocketMQProduce {
@Value("${apache.rocketmq.producer.producerGroup}")
private String producerGroup;
@Value("${apache.rocketmq.namesrvAddr}")
private String namesrvAddr;
//@PostConstruct
public void defaultMQProducer() {
DefaultMQProducer producer = new DefaultMQProducer(producerGroup);
producer.setNamesrvAddr(namesrvAddr);
try {
producer.start();
StopWatch stop = new StopWatch();
stop.start();
/*for(int i = 0; i< 1; i++) {
SendResult result = producer.send(message);
System.out.println("发送响应:MsgId:" + result.getMsgId() + ",发送状态:" + result.getSendStatus());
}*/
for (int i = 0; i < 10; i++) {
String messageContent = "消息:" + i;
Message message = new Message("TopicTestA", "push", messageContent.getBytes(RemotingHelper.DEFAULT_CHARSET));
//send的最后一个参数指定发送给哪个消息队列
SendResult result = producer.send(message, new MessageQueueSelector() {
@Override
public MessageQueue select(List<MessageQueue> mqs, Message msg, Object arg) {
Integer id = (Integer) arg;
int index = id % mqs.size();
return mqs.get(index);
}
}, Integer.valueOf(i));
System.out.println("发送响应:MsgId:" + result.getMsgId() + ",发送状态:" + result.getSendStatus());
}
stop.stop();
} catch (MQClientException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (RemotingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (MQBrokerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
producer.shutdown();
}
}
}6. 消费者代码 MessageListenerConcurrently 同步消费消息,而且是无序的
@Component
public class RocketMQConsumer {
@Value("${apache.rocketmq.consumer.PushConsumer}")
private String consumerGroup;
@Value("${apache.rocketmq.namesrvAddr}")
private String namesrvAddr;
@PostConstruct
public void defaultMQPushConsumer() {
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(consumerGroup);
//设置最多一次消费多少条
consumer.setConsumeMessageBatchMaxSize(1);
consumer.setNamesrvAddr(namesrvAddr);
// consumer.setMessageModel(MessageModel.CLUSTERING);
try {
consumer.subscribe("TopicTestA", "push");
consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_FIRST_OFFSET);
consumer.registerMessageListener((MessageListenerConcurrently) (list, context) -> {
try {
for (MessageExt messageExt : list) {
System.out.println("messageExt: " + messageExt);// 输出消息内容
String messageBody = new String(messageExt.getBody(), RemotingHelper.DEFAULT_CHARSET);
/*System.out.println("----消费响应:msgId : " + messageExt.getMsgId() + ", msgBody : " + messageBody
+ " " + Thread.currentThread().getName());*/
int reconsumeTimes = messageExt.getReconsumeTimes();
//消费次数为2时,将消息消费掉
if(reconsumeTimes >= 2){
System.out.println("----消费响应:msgId : " + messageExt.getMsgId() + ", msgBody : " + messageBody
+ " " + Thread.currentThread().getName()
+ " 消费次数:" + reconsumeTimes);
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}else{
System.out.println("++++消费响应:msgId : " + messageExt.getMsgId() + ", msgBody : " + messageBody
+ " " + Thread.currentThread().getName()
+ " 消费次数:" + reconsumeTimes);
return ConsumeConcurrentlyStatus.RECONSUME_LATER;
}
}
} catch (Exception e) {
e.printStackTrace();
return ConsumeConcurrentlyStatus.RECONSUME_LATER; // 稍后再试
}
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS; // 消费成功
});
consumer.start();
} catch (MQClientException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
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