版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/wanghang88/article/details/82840340
1,实现rabbitmq所需要依赖包
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
<version>${spring-boot.version}</version>
</dependency>
2,生产者基本配置
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
# 开启发送确认(生产者发送消息相关)
spring.rabbitmq.publisher-confirms=true
# 开启发送失败退回(生产者发送消息相关)
spring.rabbitmq.publisher-returns=true
a),队列
@Configuration
public class RabbitConfig {
public final static String queueName = "ad_queue";
}
b),发送消息
@Component
public class Sender implements RabbitTemplate.ConfirmCallback, RabbitTemplate.ReturnCallback{
private static Map<String, Integer> map = new ConcurrentHashMap<>();
private final Logger emailLogger = LoggerFactory.getLogger("emailLogger");
@Autowired
private RabbitTemplate rabbitTemplate;
public void send(String routingKey, String content) {
this.rabbitTemplate.setMandatory(true);
this.rabbitTemplate.setConfirmCallback(this);
this.rabbitTemplate.setReturnCallback(this);
this.rabbitTemplate.setRoutingKey(routingKey);
//这样我们就能知道,发送失败的是哪条消息了
this.rabbitTemplate.correlationConvertAndSend(content, new CorrelationData(content));
// this.rabbitTemplate.convertAndSend(routingKey, content);
}
/**
* 确认后回调:
* @param correlationData
* @param ack
* @param cause
*/
@Override
public void confirm(CorrelationData correlationData, boolean ack, String cause) {
if (!ack) {
/**
* 我们这里仅通过打印日志、发送邮件来预警,并没有实现自动重试机制:
* 1、将发送失败重新发送到一个队列中:fail-queue,然后可以定时对这些消息进行重发
* 2、在本地定义一个缓存map对象,定时进行重发
* 3、为了更安全,可以将所有发送的消息保存到db中,并设置一个状态(是否发送成功),定时扫描检查是否存在未成功发送的信息
* 这块知识,我们后期讲"分布式事务"的时候,在深入讲解这块内容
*/
emailLogger.error("send ack fail, cause = {}, correlationData = {}", cause, correlationData.getId());
} else {
System.out.println("send ack success");
}
}
/**
* 失败后return回调:
*
* @param message
* @param replyCode
* @param replyText
* @param exchange
* @param routingKey
*/
@Override
public void returnedMessage(Message message, int replyCode, String replyText, String exchange, String routingKey) {
emailLogger.error("send fail return-message = " + new String(message.getBody()) + ", replyCode: " + replyCode + ", replyText: " + replyText + ", exchange: " + exchange + ", routingKey: " + routingKey);
String str = new String(message.getBody());
retrySend(str, 3);
}
private void retrySend(String content, int retryTime){
if(map.containsKey(content)){
int count = map.get(content);
count++;
map.put(content, count);
} else {
map.put(content, 1);
}
if(map.get(content) <= retryTime) {
send(RabbitConfig.queueName, content);
}
}
}
3,消费者
a)基本配置
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
# 开启ACK(消费者消息确认机制)
spring.rabbitmq.listener.simple.acknowledge-mode=manual
b)队列(包括死信队列):
@Configuration
public class RabbitConfig {
public final static String queueName = "ad_queue";
/**
* 死信队列:
*/
public final static String deadQueueName = "ad_dead_queue";
public final static String deadRoutingKey = "ad_dead_routing_key";
public final static String deadExchangeName = "ad_dead_exchange";
/**
* 死信队列 交换机标识符
*/
public static final String DEAD_LETTER_QUEUE_KEY = "x-dead-letter-exchange";
/**
* 死信队列交换机绑定键标识符
*/
public static final String DEAD_LETTER_ROUTING_KEY = "x-dead-letter-routing-key";
@Bean
public Queue helloQueue() {
//将普通队列绑定到私信交换机上
Map<String, Object> args = new HashMap<>(2);
args.put(DEAD_LETTER_QUEUE_KEY, deadExchangeName);
args.put(DEAD_LETTER_ROUTING_KEY, deadRoutingKey);
Queue queue = new Queue(queueName, true, false, false, args);
return queue;
}
/**
* 死信队列:
*/
@Bean
public Queue deadQueue() {
Queue queue = new Queue(deadQueueName, true);
return queue;
}
@Bean
public DirectExchange deadExchange() {
return new DirectExchange(deadExchangeName);
}
@Bean
public Binding bindingDeadExchange(Queue deadQueue, DirectExchange deadExchange) {
return BindingBuilder.bind(deadQueue).to(deadExchange).with(deadRoutingKey);
}
}
c)消费者消费消息:
@Component
@RabbitListener(queues = RabbitConfig.queueName)
public class Receiver {
private Logger logger = LoggerFactory.getLogger(Receiver.class);
private final Logger emailLogger = LoggerFactory.getLogger("emailLogger");
@Resource
UpdateRedisServiceImpl updateRedisService;
@RabbitHandler
public void process(String content, Channel channel, Message message) {
logger.info("handle msg begin = {}", content);
AdMessage adMessage = JSON.parseObject(content, AdMessage.class);
Long id = adMessage.getId();
int retryTimes = 0;
while (retryTimes < 5) {
//消费者做幂等处理(当然这只是对单台机器而言没有问题,如果是分布式集群环境,这种是不行的,后续我们会继续优化这块):防止相同类型的广告id更新问题
synchronized (AdLock.cacheLock) {
//更新redis数据:
if(!updateRedisService.updateRedis(id)){
retryTimes++;
}
}
break;
}
if (retryTimes >= 3) {
//当有多次更新失败的时候,发送邮件通知:
emailLogger.error("处理MQ[" + content + "]失败[" + retryTimes + "]次");
}
try {
if (retryTimes >= 5) {
//当有很多次更新失败的时候,丢弃这条消息或者发送到死信队列中
channel.basicNack(message.getMessageProperties().getDeliveryTag(), false,false);
}else {
//告诉服务器收到这条消息 已经被我消费了 可以在队列删掉;否则消息服务器以为这条消息没处理掉 后续还会在发
channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
}
} catch (Exception e){
logger.error("消息确认失败", e);
}
logger.info("handle msg finished = {}", content);
}
}