Golang语言操作RabbitMQ
1.准备
1.1 安装包依赖
go get "github.com/streadway/amqp"
1.2 官方文档
https://github.com/rabbitmq/rabbitmq-tutorials/tree/master/go
2.普通模式
2.1 生产者
package main
import (
"fmt"
"log"
"os"
"strings"
"github.com/streadway/amqp"
"time"
)
/*
默认点对点模式
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func main() {
// 连接
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close()
// 打开一个并发服务器通道来处理消息
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close()
// 申明一个队列
q, err := ch.QueueDeclare(
"task_queue", // name
true, // durable 持久性的,如果事前已经声明了该队列,不能重复声明
false, // delete when unused
false, // exclusive 如果是真,连接一断开,队列删除
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
body := bodyFrom(os.Args)
// 发布
err = ch.Publish(
"", // exchange 默认模式,exchange为空
q.Name, // routing key 默认模式路由到同名队列,即是task_queue
false, // mandatory
false,
amqp.Publishing{
// 持久性的发布,因为队列被声明为持久的,发布消息必须加上这个(可能不用),但消息还是可能会丢,如消息到缓存但MQ挂了来不及持久化。
DeliveryMode: amqp.Persistent,
ContentType: "text/plain",
Body: []byte(body),
})
failOnError(err, "Failed to publish a message")
log.Printf(" [x] Sent %s", body)
}
func bodyFrom(args []string) string {
var s string
if (len(args) < 2) || os.Args[1] == "" {
s = fmt.Sprintf("%s-%v","hello", time.Now())
} else {
s = strings.Join(args[1:], " ")
}
return s
}
2.2 消费者
package main
import (
"bytes"
"fmt"
"github.com/streadway/amqp"
"log"
"time"
)
/*
默认点对点模式
工作方,多个,拿发布方的消息
*/
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()
// 指定队列!
q, err := ch.QueueDeclare(
"task_queue", // name
true, // durable
false, // delete when unused
false, // exclusive
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
// Fair dispatch 预取,每个工作方每次拿一个消息,确认后才拿下一次,缓解压力
err = ch.Qos(
1, // prefetch count
0, // prefetch size
false, // global
)
failOnError(err, "Failed to set QoS")
// 消费根据队列名
msgs, err := ch.Consume(
q.Name, // queue
"", // consumer
false, // auto-ack 设置为真自动确认消息
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)
dot_count := bytes.Count(d.Body, []byte("."))
t := time.Duration(dot_count)
time.Sleep(t * time.Second)
log.Printf("Done")
// 确认消息被收到!!如果为真的,那么同在一个channel,在该消息之前未确认的消息都会确认,适合批量处理
// 真时场景:每十条消息确认一次,类似
d.Ack(false)
}
}()
log.Printf(" [*] Waiting for messages. To exit press CTRL+C")
<-forever
}
3.订阅模式
3.1 生产者
package main
import (
"fmt"
"github.com/streadway/amqp"
"log"
"os"
"strings"
"time"
)
/*
广播模式
发布方
*/
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()
// 默认模式有默认交换机,广播自己定义一个交换机,交换机可与队列进行绑定
err = ch.ExchangeDeclare(
"logs", // name
"fanout", // type 广播模式
true, // durable
false, // auto-deleted
false, // internal
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare an exchange")
body := bodyFrom(os.Args)
// 发布
err = ch.Publish(
"logs", // exchange 消息发送到交换机,这个时候没队列绑定交换机,消息会丢弃
"", // routing key 广播模式不需要这个,它会把所有消息路由到绑定的所有队列
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "text/plain",
Body: []byte(body),
})
failOnError(err, "Failed to publish a message")
log.Printf(" [x] Sent %s", body)
}
func bodyFrom(args []string) string {
var s string
if (len(args) < 2) || os.Args[1] == "" {
s = fmt.Sprintf("%s-%v","hello", time.Now())
} else {
s = strings.Join(args[1:], " ")
}
return s
}
3.2 订阅 消费者
package main
import (
"fmt"
"github.com/streadway/amqp"
"log"
)
/*
广播模式
订阅方
*/
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()
// 同样要申明交换机
err = ch.ExchangeDeclare(
"logs", // name
"fanout", // type
true, // durable
false, // auto-deleted
false, // internal
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare an exchange")
// 新建队列,这个队列没名字,随机生成一个名字
q, err := ch.QueueDeclare(
"", // name
false, // durable
false, // delete when usused
true, // exclusive 表示连接一断开,这个队列自动删除
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
// 队列和交换机绑定,即是队列订阅了发到这个交换机的消息
err = ch.QueueBind(
q.Name, // queue name 队列的名字
"", // routing key 广播模式不需要这个
"logs", // exchange 交换机名字
false,
nil)
failOnError(err, "Failed to bind a queue")
// 开始消费消息,可开多个订阅方,因为队列是临时生成的,所有每个订阅方都能收到同样的消息
msgs, err := ch.Consume(
q.Name, // queue 队列名字
"", // consumer
true, // auto-ack 自动确认
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(" [x] %s", d.Body)
}
}()
log.Printf(" [*] Waiting for logs. To exit press CTRL+C")
<-forever
}
4.RPC模式
4.1 RPC 应答方
package main
import (
"fmt"
"log"
"strconv"
"github.com/streadway/amqp"
)
/*
RPC模式
应答方
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func fib(n int) int {
if n == 0 {
return 0
} else if n == 1 {
return 1
} else {
return fib(n-1) + fib(n-2)
}
}
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()
q, err := ch.QueueDeclare(
"rpc_queue", // name
false, // durable
false, // delete when usused
false, // exclusive
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
// 公平分发 没有这个则round-robbin
err = ch.Qos(
1, // prefetch count
0, // prefetch size
false, // global
)
failOnError(err, "Failed to set QoS")
// 消费,等待请求
msgs, err := ch.Consume(
q.Name, // queue
"", // consumer
false, // 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() {
//请求来了
for d := range msgs {
n, err := strconv.Atoi(string(d.Body))
failOnError(err, "Failed to convert body to integer")
log.Printf(" [.] fib(%d)", n)
// 计算
response := fib(n)
// 回答
err = ch.Publish(
"", // exchange
d.ReplyTo, // routing key
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "text/plain",
CorrelationId: d.CorrelationId, //序列号
Body: []byte(strconv.Itoa(response)),
})
failOnError(err, "Failed to publish a message")
// 确认回答完毕
d.Ack(false)
}
}()
log.Printf(" [*] Awaiting RPC requests")
<-forever
}
4.2 RPC 请求方
package main
import (
"fmt"
"log"
"math/rand"
"os"
"strconv"
"strings"
"time"
"github.com/streadway/amqp"
)
/*
RPC模式
请求方
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func randomString(l int) string {
bytes := make([]byte, l)
for i := 0; i < l; i++ {
bytes[i] = byte(randInt(65, 90))
}
return string(bytes)
}
func randInt(min int, max int) int {
return min + rand.Intn(max-min)
}
func fibonacciRPC(n int) (res int, err error) {
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()
// 队列声明
q, err := ch.QueueDeclare(
"", // name
false, // durable
false, // delete when usused
true, // exclusive 为真即连接断开就删除
false, // noWait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
msgs, err := ch.Consume(
q.Name, // queue
"", // consumer
true, // auto-ack
false, // exclusive 这个为真,服务器会认为这是该队列唯一的消费者
false, // no-local
false, // no-wait
nil, // args
)
failOnError(err, "Failed to register a consumer")
corrId := randomString(32)
err = ch.Publish(
"", // exchange
"rpc_queue", // routing key
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "text/plain",
CorrelationId: corrId,
ReplyTo: q.Name,
Body: []byte(strconv.Itoa(n)),
})
failOnError(err, "Failed to publish a message")
for d := range msgs {
if corrId == d.CorrelationId {
res, err = strconv.Atoi(string(d.Body))
failOnError(err, "Failed to convert body to integer")
break
}
}
return
}
func main() {
rand.Seed(time.Now().UTC().UnixNano())
n := bodyFrom(os.Args)
log.Printf(" [x] Requesting fib(%d)", n)
res, err := fibonacciRPC(n)
failOnError(err, "Failed to handle RPC request")
log.Printf(" [.] Got %d", res)
}
func bodyFrom(args []string) int {
var s string
if (len(args) < 2) || os.Args[1] == "" {
s = "30"
} else {
s = strings.Join(args[1:], " ")
}
n, err := strconv.Atoi(s)
failOnError(err, "Failed to convert arg to integer")
return n
}
Golang语言操作RabbitMQ
https://www.gmtgo.com/35395.html