[Go]RPC

GOB

Go官方有提供net/rpc的RPC套件。此套件提供GOB的編/解碼，且支援TCP或HTTP傳輸方式。它可以在伺服器端註冊多個不同類型物件。

遠端存取的要求條件

• 方法的類型可輸出
• 方法的本體可輸出
• 方法必須要有兩個參數是輸出或內建
• 方法的第二個參數是指標型
• 方法的返回類型為error

伺服器端

package main

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

func main() {
	algorithm := new(Algorithm)
	fmt.Println("Algorithm start", algorithm)
	rpc.Register(algorithm)
	rpc.HandleHTTP()
	err := http.ListenAndServe(":8808", nil)
	if err != nil {
		fmt.Println("err===", err.Error())
	}
}

type Algorithm int

type Args struct {
	X, Y int
}

type Response int

func (t *Algorithm) Sum(args *Args, reply *int) error {
	*reply = args.X + args.Y
	fmt.Println("Exec Sum ", reply)
	return nil
}

用戶端

package main

import (
	"fmt"
	"log"
	"net/rpc"
	"os"
	"strconv"
)

type ArgsTwo struct {
	X, Y int
}

func main() {
	client, err := rpc.DialHTTP("tcp", "127.0.0.1:8808")
	if err != nil {
		log.Fatal("ERROR：DialHTTP", err)
	}
	i1, _ := strconv.Atoi(os.Args[1])
	i2, _ := strconv.Atoi(os.Args[2])
	args := ArgsTwo{i1, i2}
	var reply int
	err = client.Call("Algorithm.Sum", args, &reply)
	if err != nil {
		log.Fatal("Call Sum algorithm error:", err)
	}
	fmt.Printf("Algorithm Sum: %d+%d=%d\n", args.X, args.Y, reply)
}

JSON

Go官方有提供net/rpc的RPC套件。此套件提供json-rpc的編/解碼。

伺服器端

package main

import (
	"fmt"
	"net"
	"net/rpc"
	"net/rpc/jsonrpc"
)

func init() {
	fmt.Println("JSON編碼RPC，不是gob編碼，其他的和RPC概念一模一樣，")
}

type ArgsLanguage struct {
	Java, Go string
}

type Programmer string

func (m *Programmer) GetSkill(al *ArgsLanguage, skill *string) error {
	*skill = "Skill1:" + al.Java + "，Skill2" + al.Go
	return nil
}

func main() {
	str := new(Programmer)
	rpc.Register(str)

	tcpAddr, err := net.ResolveTCPAddr("tcp", ":8085")
	if err != nil {
		fmt.Println("ResolveTCPAddr err=", err)
	}

	listener, err := net.ListenTCP("tcp", tcpAddr)
	if err != nil {
		fmt.Println("tcp listen err=", err)
	}

	for {
		conn, err := listener.Accept()
		if err != nil {
			continue
		}
		jsonrpc.ServeConn(conn)
	}
}

用戶端

package main

import (
	"fmt"
	"log"
	"net/rpc/jsonrpc"
)

func main() {
	fmt.Println("client start......")
	client, err := jsonrpc.Dial("tcp", "127.0.0.1:8085")
	if err != nil {
		log.Fatal("Dial err=", err)
	}
	send := Send{"Java", "Go"}
	var receive string
	err = client.Call("Programmer.GetSkill", send, &receive)
	if err != nil {
		fmt.Println("Call err=", err)
	}
	fmt.Println("receive", receive)

}

type Send struct {
	Java, Go string
}