1.2.Go如何使用pulsar

1.首先引入 

github.com/apache/pulsar-client-go/pulsar

2.启动pulsar的client

/*启动一个pulsar  client*/

defer func() {

  ifr:=recover();r!=nil{

     logger.Fatalf(ctx,"pulsar is down stack[%+v] recover[%+v]",string(debug.Stack()),r)

   }

}()

varerrerror

SunacClient,err=pulsar.NewClient(pulsar.ClientOptions{

  URL:conf.PulsarSetting.Url,

})

iferr!=nil{

  logger.Errorf(ctx,"setup pulsar failed to get new client err[%v]",err)

  return

}

3.生产者

funcSendMessage(ctx*gin.Context,clientpulsar.Client,topicstring,msg []byte) {

  /*

   提供生产者方法

   */

   /*

     （1）初始化一个producer设置好主题

   */

  producer,err:=client.CreateProducer(pulsar.ProducerOptions{

     Topic:topic,

  })

  /*

    */

  iferr!=nil{

     logger.Errorf(ctx,"SendMessage Error[%v]",err)

   }

  /*

    */

   //（2）把消息结构体发给pusar

  _,err=producer.Send(context.Background(), &pulsar.ProducerMessage{

     Payload:msg,

     EventTime:time.Now(),

  })

  logger.Infof(ctx,"Pulsar_Published_SendMessage [%v]",string(msg))

  deferproducer.Close()

  iferr!=nil{

     logger.Errorf(ctx,"Failed to publish message",err)

   }

}

4.消费者

funcnewConsumer(ctx*gin.Context,clientpulsar.Client,topicstring) {

  //创建消费者

  defer func() {

     ifr:=recover();r!=nil{

        logger.Fatalf(ctx,"Pulsar is down [stack=%+v] [recover=%+v]",string(debug.Stack()),r)

      }

   }()

  consumer,err:=client.Subscribe(pulsar.ConsumerOptions{

     Topics:[]string{topic},

     SubscriptionName:conf.RcSeverSetting.ServiceName,

     Type:pulsar.Failover,

  })

  iferr!=nil{

     logger.Errorf(ctx,"NewConsumer failed to start pulsar consumer,err[%v]",err)

     return

  }

  deferconsumer.Close()

  //循环的获取pulsar的消息     e

  for{

     msg,err:=consumer.Receive(context.Background())

     iferr!=nil{

        logger.Error(ctx,"newConsumer failed to receive message,err[%v],topic[%s]",err,msg.Topic())

      }

     //根据消息的类型 对消息进行处理

     logger.Infof(ctx,"newConsumer RCPULSARFACEADD topic[%s] msg[%v]",msg.Topic(),string(msg.Payload()))

     switchmsg.Topic() {

     casecommon.RCPULSARFACEADD://人脸添加或更新

        logger.Infof(ctx,"newConsumer RCPULSARFACEADD topic[%s]",msg.Topic())

     casecommon.RCPULSARPASSRECORDADD://通行记录添加

        logger.Infof(ctx,"newConsumer RCPULSARPASSRECORDADD topic[%s]",msg.Topic())

     default:

logger.Errorf(ctx,"pulsar consumer got an wrong topic,message[%v]",msg)

      }

     iferr!=nil{

        logger.Errorf(ctx,"newConsumer handle got error,msg will nack,topic=[%s],err=[%v]",topic,err)

        consumer.Nack(msg)//When a message is "negatively acked" it will be marked for redelivery after some fixed delay

        continue

     }

     consumer.Ack(msg)

   }

}