golang簡單擷取上傳檔案大小的實現代碼

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

package mainimport ("fmt""io""log""net/http""os")// 擷取檔案大小的介面type Size interface {Size() int64}// 擷取檔案資訊的介面type Stat interface {Stat() (os.FileInfo, error)}// hello world, the web serverfunc HelloServer(w http.ResponseWriter, r *http.Request) {if "POST" == r.Method {file, _, err := r.FormFile("userfile")if err != nil {http.Error(w, err.Error(), 500)return}if statInterface, ok := file.(Stat); ok {fileInfo, _ := statInterface.Stat()fmt.Fprintf(w, "上傳檔案的大小為: %d", fileInfo.Size())}if sizeInterface, ok := file.(Size); ok {fmt.Fprintf(w, "上傳檔案的大小為: %d", sizeInterface.Size())}return}// 上傳頁面w.Header().Add("Content-Type", "text/html")w.WriteHeader(200)html := `<form enctype="multipart/form-data" action="/hello" method="POST">    Send this file: <input name="userfile" type="file" />    <input type="submit" value="Send File" /></form>`io.WriteString(w, html)}func main() {http.HandleFunc("/hello", HelloServer)err := http.ListenAndServe(":12345", nil)if err != nil {log.Fatal("ListenAndServe: ", err)}}