01、通过log模块制作一个闭包http函数

1、通过log模块记录http请求的信息，需要在每个http函数中加入该函数

func accesslog(ip,method,url,userAgent string,status int){
    log.Printf("%s %s %s",ip,method,url)
}
func GetUsers(w http.ResponseWriter,r *http.Request){
    tpl :=template.Must(template.ParseFiles("template/user.html"))
    tmp.ExecuteTemplate(w,"user.html",services.GetUsers())
    accessLog(r.RemoteAddr,r.Method,r.URL.String(),r.Header.Get("UserAgent"))
}

2、通过Wrapper函数套用http函数，记录日志

func accesslog(ip,method,url,userAgent string,status int){
    log.Printf("%s %s %s",ip,method,url)
}
func GetUsers(w http.ResponseWriter,r *http.Request){
    tpl :=template.Must(template.ParseFiles("template/user.html"))
    tmp.ExecuteTemplate(w,"user.html",services.GetUsers())
}
func GetUsersWrapper(w http.ResponseWriter,r *http.Request){
    GetUser(w,r)
    accessLog(r.RemoteAddr,r.Method,r.URL.String(),r.Header.Get("UserAgent"))
}
func Register(){
    //绑定GetUsersWrapper 函数
    http.HandleFunc("/",controllers.GetUsersWrapper)
}

3、通过闭包生成函数的方式，记录日志

func accesslog(ip,method,url,userAgent string,status int){
}
var logger *log.Logger
// logger需要初始化
func InitLogger(writer log.Writer){
    logger =log.New(writer,"",0)
}
//工厂函数
func LoggerWrapper(action http.HandlerFunc) http.HandlerFunc{
return func(w http.ResponseWriter,r *http.Request){
    action（w,r)
    //logger未初始化，就不记录日志
    if logger !=nil{
        logger.Printf("%s %s %s",ip,method,url)
    }
}
}
var GetUserWrapper2 = LoggerWrapper(GetUsers)
func Register(){
    //绑定GetUsersWrapper2 函数,或套用LoggerWrapper函数
    http.HandleFunc("/",controllers.GetUsersWrapper)
    //或
    // http.HandleFunc("/",LoggerWrapper(GetUsers))
}