Golang http 服务器

package main

import (
    "net/http"
    "fmt"
)

func main() {
    app := http.NewServeMux()
    app.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintln(w,fmt.Sprint("Method:",r.Method))
        fmt.Fprintln(w,"Hello World")
    })
    http.ListenAndServe("127.0.0.1:8080", app)
}