http.ServeFile()

见下面的草图。

fileHandler.ServeHTTP()
package main

import (
    "log"
    "net/http"
    "path"
    "path/filepath"
    "strings"
)

func main() {
    mux := http.NewServeMux()

    //staticHandler := http.FileServer(http.Dir("./templates"))
    staticHandler := fileServer("./templates")

    mux.Handle("/", http.StripPrefix("/", staticHandler))
    log.Printf("listening")
    log.Fatal(http.ListenAndServe(":8080", mux))
}

// returns custom file server
func fileServer(root string) http.Handler {
    return &fileHandler{root}
}

// custom file server
type fileHandler struct {
    root string
}

func (f *fileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    upath := r.URL.Path
    if !strings.HasPrefix(upath, "/") {
        upath = "/" + upath
        r.URL.Path = upath
    }
    name := filepath.Join(f.root, path.Clean(upath))
    log.Printf("fileHandler.ServeHTTP: path=%s", name)
    http.ServeFile(w, r, name)
}