关于rabbitmq 的入门和使用，网络上的资料甚多，在此不再赘述。可以看文章末尾的参考资料。
对rabbitmq的golang客户端二度封装，通过订阅/发布的模式使消息的获取和接收进行解耦，从而支持多类型的消息处理，例如对于同一个消息，分别进行入库和转发。
（一）rabbitmq调用端封装
1、定义调用端接口
// Defines our interface for connecting and consuming messages.
type RabbitmqClient interface {
ConnectToBroker(connectionString string)
Publish(msg []byte, exchangeName , exchangeType ,bindingKey string) error
PublishOnQueue(msg []byte, queueName string) error
Subscribe(exchangeName , exchangeType , consumerName ,
bindingKey string, handlerFunc func(amqp.Delivery)) error
SubscribeToQueue(queueName string, consumerName string, handlerFunc func(amqp.Delivery)) error
Close()
}
2、实现接口的类图结构
具体的实现请看 github(作者：eriklupander )
（二）使用接收者解耦
定义个接收者，包含对消息的处理函数，声明绑定交换器和消息队列等参数，目的是可以定义多个接收者对消息异步进行不同的操作
//定义接受者，使其与客户端解耦
type Receiver struct {
//接收者的各项信息
ExchangeName string
ExchangeType string
QueueName string
BindingKey string
ConsumerName string
Deliveries chan amqp.Delivery
handlerFunc func(msg amqp.Delivery) //定义一个处理方法
}
（三）消费端 封装，组合调用端和接受者
定义消费端实现订阅、发布模式，持有rabbitmq客户端及多个接收者，使多个接收者能接收到消息。
1、类图结构
2、代码实现
//定义消费端,消费端持有调用端和接收者
type Consumer struct {
Client RabbitmqClient //一个客户端
Receivers []*Receiver
}
func (c *Consumer)Add(rec ...*Receiver){
//添加接收器
c.Receivers=append(c.Receivers,rec...)
}
//订阅接收器到交换器
func (c *Consumer)Subscribe(){
for _,receiver:=range c.Receivers{
err:=c.Client.Subscribe(receiver.ExchangeName,
receiver.ExchangeType,
receiver.ConsumerName,
receiver.BindingKey,
receiver.handlerFunc)
if err != nil {
log.Printf("Subscribe error: %s %s ",receiver,err)
}
}
}
//订阅接收器到特定队列
func (c *Consumer)SubscribeToQueue(){
for _,receiver:=range c.Receivers{
err:=c.Client.SubscribeToQueue(receiver.QueueName,
receiver.ConsumerName,
receiver.handlerFunc)
if err != nil {
log.Printf("SubscribeToQueue error: %s %s ",receiver,err)
}
}
}
（四）测试
1、定义一个 topic 类型的交换器，使用 routingkey路由键发送特定的类型消息。
func TestConsumer(t *testing.T) {
var receiver *Receiver
var client *MessagingClient
var consumer Consumer
var exname="chat" //交换器命名
var extype=amqp.ExchangeTopic //使用tpoic交换器类型
var routingkey="*.waiwen" //消息路由键，代表发送给waiwen的信息
var queueName="waiwen" //命名一个队列名称
client=&MessagingClient{}
//defer client.Close()
var connectionStr="amqp://admin:admin@192.168.172.2:5672/" //链接
client.ConnectToBroker(connectionStr)
go func() {
var body=[]byte("hello waiwen")
err:=client.Publish(body,exname,extype,"xiaoming.waiwen",queueName)
if err!=nil{
log.Printf("publish msg error : %s \n",err)
}else{
log.Printf("A message was sent: %s \n", body)
}
}()
receiver=&Receiver{
ExchangeType:extype,
ExchangeName:exname,
ConsumerName:"",
QueueName:queueName,
BindingKey:routingkey,
Deliveries:make(chan amqp.Delivery),
handlerFunc: func(msg amqp.Delivery) {
log.Printf("get message from queue: %v \n",string(msg.Body))
},
}
consumer=Consumer{
Client:client,
Receivers:[]*Receiver{},
}
consumer.Add(receiver)
consumer.Subscribe()
select {}
}
2、测试结果：
