Go RPC Call

package main /*from  w  w  w  .ja  va2  s .c  o m*/

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

type Server struct {} 
func (this *Server) Negate(i int64, reply *int64) error { 
    *reply = -i 
    return nil 
} 

func server() { 
    rpc.Register(new(Server)) 
    ln, err  := net.Listen("tcp", ":9999") 
    if err  != nil { 
        fmt.Println(err) 
        return 
    } 
    for { 
        c, err  := ln.Accept() 
        if err  != nil { 
            continue 
        } 
        go rpc.ServeConn(c) 
    } 
} 
func client() { 
    c, err  := rpc.Dial("tcp", "127.0.0.1:9999") 
    if err  != nil { 
        fmt.Println(err) 
        return 
    } 
    var result int64 
    err = c.Call("Server.Negate", int64(999), &result) 
    if err  != nil { 
        fmt.Println(err) 
    } else { 
        fmt.Println("Server.Negate(999) =", result) 
    } 
} 
func main() { 
    go server() 
    go client() 
    var input string 
    fmt.Scanln(&input) 
}