2.4 进一步改进rpc调用过程

前面的rpc调用虽然简单，但是和普通的http的调用差异不大，这次我们解决下面的问题：

1. serviceName统一和名称冲突的问题

1. server端和client端如何统一serviceName
2. 多个server的包中serviceName同名的问题

新建handler/handler.go文件内容如下： 为什么要新建一个文件？ - 解耦

package handler
const HelloServiceName = "handler/HelloService"

1. 服务端

package main
import (
    "net"
    "net/rpc"
    "start/rpc_ch01/handler"
)
type HelloService struct {}
func (s *HelloService) Hello(request string, reply *string) error {
    *reply = "hello "+ request
    return nil
}
func main(){
    _ = rpc.RegisterName(handler.HelloServiceName, &HelloService{})
    listener, err := net.Listen("tcp", ":1234")
    if err != nil {
        panic("监听端口失败")
    }
    conn, err := listener.Accept()
    if err != nil {
        panic("建立链接失败")
    }
    rpc.ServeConn(conn)
}

2. 客户端

package main
import (
    "fmt"
    "net/rpc"
    "start/rpc_ch01/handler"
)
func main() {
    client, err := rpc.Dial("tcp", "localhost:1234")
    if err != nil {
        panic("连接到服务器失败")
    }
    var reply string
    err = client.Call(handler.HelloServiceName+".Hello", "imooc", &reply)
    if err != nil {
        panic("服务调用失败")
    }
    fmt.Println(reply)
}

2. 继续屏蔽HelloServiceName和Hello函数名称

1. handler源码

package handler
type HelloService struct{}
func (s *HelloService) Hello(request string, reply *string) error {
    *reply = "hello " + request
    return nil
}

2. 服务端代理

package server_proxy
import "net/rpc"
const HelloServiceName = "handler/HelloService"
type HelloServiceInterface interface {
    Hello(request string, reply *string) error
}
func RegisterHelloService(srv HelloServiceInterface) error {
    return rpc.RegisterName(HelloServiceName, srv)
}

3. 服务端

package main
import (
    "net"
    "net/rpc"
    "start/rpc_ch01/handler"
    "start/rpc_ch01/server_proxy"
)
func main(){
    hellohandler := &handler.HelloService{}
    _ = server_proxy.RegisterHelloService(hellohandler)
    listener, err := net.Listen("tcp", ":1234")
    if err != nil {
        panic("监听端口失败")
    }
    conn, err := listener.Accept()
    if err != nil {
        panic("建立链接失败")
    }
    rpc.ServeConn(conn)
}

4. 客户端代理

package client_proxy
import "net/rpc"
const HelloServiceName = "handler/HelloService"
type HelloServiceClient struct{
    *rpc.Client
}
func NewClient(address string) HelloServiceClient {
    conn, err := rpc.Dial("tcp", address)
    if err != nil {
        panic("连接服务器错误")
    }
    return HelloServiceClient{conn}
}
func (c *HelloServiceClient) Hello(request string, reply *string) error {
    err := c.Call(HelloServiceName+".Hello", request, reply)
    if err != nil {
        return err
    }
    return nil
}

5. 客户端

package main
import (
    "fmt"
    "start/rpc_ch01/client_proxy"
)
func main(){
    client := client_proxy.NewClient("localhost:1234")
    var reply string
    err := client.Hello("bobby",&reply)
    if err != nil {
        panic("调用失败")
    }
    fmt.Println(reply)
}