使用net/rpc构建微服务

• 使用rpc启动一个订单中心服务

package main

import (
   "net"
   "net/http"
   "net/rpc"
   "time"
)

type OrderCenter struct {
}

//暴露的方法必须符合 func (t *T) MethodName(argType T1, replyType *T2) error 形式
func (order *OrderCenter) GetInfo(res int, rep *map[string]interface{}) error {
   time.Sleep(4 * time.Second)
   *rep = map[string]interface{}{
      "name":    "奶油蛋糕",
      "price":   52.00,
      "orderId": res,
   }
   return nil
}

func (order *OrderCenter) OrderPay(res int, rep *int) error {
   time.Sleep(3 * time.Second)
   *rep = 200
   return nil
}

func main() {
   orderCenterServer := new(OrderCenter)
   err := rpc.Register(orderCenterServer)
   if err != nil {
      panic(err)
   }
   rpc.HandleHTTP()
   listen, err := net.Listen("tcp", ":8081")
   defer listen.Close()

   if err != nil {
      panic(err)
   }
   http.Serve(listen, nil)
}

• 客户端同步调用

package main

import (
	"fmt"
	"net/rpc"
)

func main() {
	client, err := rpc.DialHTTP("tcp", "localhost:8081")
　　　　　client.Close()

	if err != nil {
		panic(err)
	}
	var orderId int
	orderId = 10

	var orderInfo map[string]interface{}

	err = client.Call("OrderCenter.GetInfo", orderId, &orderInfo)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(orderInfo)

	var status int
	err = client.Call("OrderCenter.OrderPay", orderId, &status)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(status)
}

输出内容

&map[name:奶油蛋糕 orderId:10 price:52]
支付失败
<nil>

• 客户端异步调用

package main

import (
	"fmt"
	"net/rpc"
)

func main() {
	client, err := rpc.DialHTTP("tcp", "localhost:8081")
	defer client.Close()

	if err != nil {
		panic(err)
	}
	var orderId int = 10

	callChan := make([]chan *rpc.Call, 0, 2)

	var orderInfo map[string]interface{}
	infoCall := client.Go("OrderCenter.GetInfo", orderId, &orderInfo, nil)
	callChan = append(callChan, infoCall.Done)

	var status int
	statusCall := client.Go("OrderCenter.OrderPay", orderId, &status, nil)
	callChan = append(callChan, statusCall.Done)

	for _, chanCall := range callChan {
		data := <-chanCall
		switch data.ServiceMethod {
		case "OrderCenter.OrderPay":
			d := data.Reply.(*int)
			fmt.Println(*d)
		case "OrderCenter.GetInfo":
			d := data.Reply.(*map[string]interface{})
			fmt.Println(*d)
		}
	}
}