学习笔记 | Go语言操作RabbitMQ ( 3 )

1、路由模式
路由模式跟订阅模式类似，只不过在订阅模式的基础上加上了类型，订阅模式是分发到所有绑定到交换机的队列，路由模式只分发到绑定在交换机上面指定路由键的队列，即一个消息可被多个消费者获取，并且消息的目标队列可以被生产者绑定。生产者申明一个direct类型交换机，然后发送消息到这个交换机指定路由键。消费者指定消费这个交换机的这个路由键，即可接收到消息，其他消费者收不到。

1、路由模式创建实例

func NewRabbitMQRouting(exchangeName string,routingKey string) *RabbitMQ {
   //创建RabbitMQ实例
   rabbitmq := NewRabbitMQ("",exchangeName,routingKey)
   var err error
   //获取connection
   rabbitmq.conn, err = amqp.Dial(rabbitmq.Mqurl)
   rabbitmq.failOnErr(err,"failed to connect rabbitmq!")
   //获取channel
   rabbitmq.channel, err = rabbitmq.conn.Channel()
   rabbitmq.failOnErr(err, "failed to open a channel")
   return rabbitmq
}

2、路由模式发送消息

func (r *RabbitMQ) PublishRouting(message string )  {
   //1.尝试创建交换机
   err := r.channel.ExchangeDeclare(
      r.Exchange,
      //要改成direct
      "direct",
      true,
      false,
      false,
      false,
      nil,
   )



   r.failOnErr(err, "Failed to declare an excha"+
      "nge")



   //2.发送消息
   err = r.channel.Publish(
      r.Exchange,
      //要设置
      r.Key,
      false,
      false,
      amqp.Publishing{
         ContentType: "text/plain",
         Body:        []byte(message),
      })
}

3、路由模式接收消息

func (r *RabbitMQ) RecieveRouting() {
   //1.试探性创建交换机
   err := r.channel.ExchangeDeclare(
      r.Exchange,
      //交换机类型
      "direct",
      true,
      false,
      false,
      false,
      nil,
   )
   r.failOnErr(err, "Failed to declare an exch"+
      "ange")
   //2.试探性创建队列，这里注意队列名称不要写
   q, err := r.channel.QueueDeclare(
      "", //随机生产队列名称
      false,
      false,
      true,
      false,
      nil,
   )
   r.failOnErr(err, "Failed to declare a queue")


   //绑定队列到 exchange 中
   err = r.channel.QueueBind(
      q.Name,
      //需要绑定key
      r.Key,
      r.Exchange,
      false,
      nil)


   //消费消息
   messges, err := r.channel.Consume(
      q.Name,
      "",
      true,
      false,
      false,
      false,
      nil,
   )


   forever := make(chan bool)


   go func() {
      for d := range messges {
         log.Printf("Received a message: %s", d.Body)
      }
   }()


   fmt.Println("[#]Waiting for messages, to exit press CTRL + C")
   <-forever
}

最后提一下主题模式。
其实就是使路由能够模糊匹配

//话题模式
//创建RabbitMQ实例
func NewRabbitMQTopic(exchangeName string,routingKey string) *RabbitMQ {
	//创建RabbitMQ实例
	rabbitmq := NewRabbitMQ("",exchangeName,routingKey)
	var err error
	//获取connection
	rabbitmq.conn, err = amqp.Dial(rabbitmq.Mqurl)
	rabbitmq.failOnErr(err,"failed to connect rabbitmq!")
	//获取channel
	rabbitmq.channel, err = rabbitmq.conn.Channel()
	rabbitmq.failOnErr(err, "failed to open a channel")
	return rabbitmq
}
//话题模式发送消息
func (r *RabbitMQ) PublishTopic(message string )  {
	//1.尝试创建交换机
	err := r.channel.ExchangeDeclare(
		r.Exchange,
		//要改成topic
		"topic",
		true,
		false,
		false,
		false,
		nil,
	)

	r.failOnErr(err, "Failed to declare an excha"+
		"nge")

	//2.发送消息
	err = r.channel.Publish(
		r.Exchange,
		//要设置
		r.Key,
		false,
		false,
		amqp.Publishing{
			ContentType: "text/plain",
			Body:        []byte(message),
		})
}
//话题模式接受消息
//要注意key,规则
//其中“*”用于匹配一个单词，“#”用于匹配多个单词（可以是零个）
//匹配 imooc.* 表示匹配 imooc.hello, 但是imooc.hello.one需要用imooc.#才能匹配到
func (r *RabbitMQ) RecieveTopic() {
	//1.试探性创建交换机
	err := r.channel.ExchangeDeclare(
		r.Exchange,
		//交换机类型
		"topic",
		true,
		false,
		false,
		false,
		nil,
	)
	r.failOnErr(err, "Failed to declare an exch"+
		"ange")
	//2.试探性创建队列，这里注意队列名称不要写
	q, err := r.channel.QueueDeclare(
		"", //随机生产队列名称
		false,
		false,
		true,
		false,
		nil,
	)
	r.failOnErr(err, "Failed to declare a queue")

	//绑定队列到 exchange 中
	err = r.channel.QueueBind(
		q.Name,
		//在pub/sub模式下，这里的key要为空
		r.Key,
		r.Exchange,
		false,
		nil)

	//消费消息
	messges, err := r.channel.Consume(
		q.Name,
		"",
		true,
		false,
		false,
		false,
		nil,
	)

	forever := make(chan bool)

	go func() {
		for d := range messges {
			log.Printf("Received a message: %s", d.Body)
		}
	}()

	fmt.Println("[#]Waiting for messages, to exit press CTRL + C")
	<-forever
}