go实现消息队列

一、rabbitmq

package main

import (
	"fmt"
	"log"

	"github.com/streadway/amqp"
)

func failOnError(err error, msg string) {
     
	if err != nil {
     
		log.Fatalf("%s: %s", msg, err)
		panic(fmt.Sprintf("%s: %s", msg, err))
	}
}

func main() {
     
	conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
	failOnError(err, "Failed to connect to RabbitMQ")
	defer conn.Close()

	ch, err := conn.Channel()
	failOnError(err, "Failed to open a channel")
	defer ch.Close()

	failOnError(err, "Failed to declare a queue")

	err = ch.Qos(
		1,     // prefetch count
		0,     // prefetch size
		false, //global
	)
	failOnError(err, "Failed to set Qos")

	//发送消息
	funcSend(ch)
	//收消息
	funcRecv(ch)

}

//生产者
func funcSend(ch *amqp.Channel) {
     
	q, err := ch.QueueDeclare(
		"queue", //name
		false,   //durables
		false,   //delete when unused
		false,   //exclusive
		false,   //no wait
		nil,     //args
	)
	failOnError(err, "Failed to declare a queue")
	body := "Hello World!"
	error := ch.Publish(
		"",     // exchange
		q.Name, // routing key
		false,  // mandatory
		false,  // immediate
		amqp.Publishing{
     
			ContentType: "text/plain",
			Body:        []byte(body),
		})
	log.Printf("[x] Sent %s", body)
	failOnError(error, "Failed to publish a message")
}

//消费者
func funcRecv(ch *amqp.Channel) {
     
	q, err := ch.QueueDeclare(
		"queue", // name
		false,   // durable
		false,   // delete when unused
		false,   // exclusive
		false,   // no-wait
		nil,     // arguments
	)
	failOnError(err, "Failed to declare a queue")
	msgs, err := ch.Consume(
		q.Name, // queue
		"",     // consumer
		true,   // auto-ack
		false,  // exclusive
		false,  // no-local
		false,  // no-wait
		nil,    // args
	)
	failOnError(err, "Failed to register a consumer")
	forever := make(chan bool)
	go func() {
     
		for d := range msgs {
     
			log.Printf("Received a message: %s", d.Body)
		}
	}()
	log.Printf(" [*] Waiting for messages. To exit press CTRL+C")
	<-forever
}

二、nats-io

package main

import (
	"flag"
	"log"
	"strconv"
	"time"

	"github.com/nats-io/nats.go"
	"github.com/pborman/uuid"
)

const (
	//url   = "nats://192.168.3.125:4222"
	url = nats.DefaultURL
)

var (
	nc  *nats.Conn
	err error
)

func init() {
     
	// if nc, err = nats.Connect(url); checkErr(err) {
     
	// 	fmt.
	// }
}

func main() {
     

}

//发送消息
func sendMessage() {
     
	var (
		subj = flag.String("subj", "", "subject name")
	)
	flag.Parse()
	log.Println(*subj)
	startClient(*subj)
	time.Sleep(time.Second)
}

func startClient(subj string) {
     
	for i := 0; i < 1; i++ {
     
		id := uuid.New()
		log.Println(id)
		nc.Publish(subj, []byte(id+" Sun "+strconv.Itoa(i)))
		nc.Publish(subj, []byte(id+" Rain "+strconv.Itoa(i)))
		nc.Publish(subj, []byte(id+" Fog "+strconv.Itoa(i)))
		nc.Publish(subj, []byte(id+" Cloudy "+strconv.Itoa(i)))
	}
}

//接收消息
func receiveMessage() {
     
	var (
		servername = flag.String("servername", "y", "name for server")
		queueGroup = flag.String("group", "", "group name for Subscribe")
		subj       = flag.String("subj", "", "subject name")
	)
	flag.Parse()

	log.Println(*servername, *queueGroup, *subj)
	startService(*subj, *servername+" worker1", *queueGroup)
	startService(*subj, *servername+" worker2", *queueGroup)
	startService(*subj, *servername+" worker3", *queueGroup)
	select {
     }
}

func startService(subj, name, queue string) {
     
	go async(nc, subj, name, queue)
}

func async(nc *nats.Conn, subj, name, queue string) {
     
	nc.QueueSubscribe(subj, queue, func(msg *nats.Msg) {
     
		log.Println(name, "Received a message From Async : ", string(msg.Data))
	})
}

func checkErr(err error) bool {
     
	if err != nil {
     
		log.Println(err)
		return false
	}
	return true
}