package mainimport ( ???"fmt" ???"io" ???"io/ioutil" ???"log" ???"net/http" ???"os" ???"reflect")const ( ???UPLOAD_DIR = "./uploads")func uploadHandler(w http.ResponseWriter, r *http.Request) { ???if r.Method == "GET" { ???????io.WriteString(w, "<html><form method=\"POST\" action=\"/upload\" "+ ???????????" enctype=\"multipart/form-data\">"+ ???????????"Choose an image to upload: <input name=\"image\" type=\"file\" />"+ ???????????"<input type=\"submit\" value=\"Upload\" />"+ ???????????"</form></html>") ???????return ???} ???if r.Method == "POST" { ???????f, h, err := r.FormFile("image") ???????if err != nil { ???????????http.Error(w, err.Error(), http.StatusInternalServerError) ???????????return ???????} ???????filename := h.Filename ???????fmt.Println("filename:", filename) ???????defer f.Close() //文件流句柄 ???????t, err := os.Create(UPLOAD_DIR + "/" + filename) ???????fmt.Println("filepath:", UPLOAD_DIR+"/"+filename) ???????if err != nil { ???????????http.Error(w, err.Error(), http.StatusInternalServerError) ???????????return ???????} ???????defer t.Close() //关闭临时文件句柄 ???????if _, err := io.Copy(t, f); err != nil { ???????????http.Error(w, err.Error(), http.StatusInternalServerError) ???????????return ???????} ???????http.Redirect(w, r, "/view?id="+filename, http.StatusFound) ???}}func viewHandler(w http.ResponseWriter, r *http.Request) { ???imageId := r.FormValue("id") ???imagePath := UPLOAD_DIR + "/" + imageId ???if exists := isExists(imagePath); !exists { ???????http.NotFound(w, r) ???????return ???} ???w.Header().Set("Content-Type", "image") //HTTP响应头输出格式 ???http.ServeFile(w, r, imagePath)}func isExists(path string) bool { ???_, err := os.Stat(path) ???if err == nil { ???????return true ???} ???return os.IsExist(err)}func listHandler(w http.ResponseWriter, r *http.Request) { ???fileInfoArr, err := ioutil.ReadDir("./uploads") ???if err != nil { ???????http.Error(w, err.Error(), http.StatusInternalServerError) ???????return ???} ???var listHtml string ???for _, fileInfo := range fileInfoArr { ???????imgid := fileInfo.Name ???????fmt.Println("type:", reflect.TypeOf(imgid)) ???????listHtml += "<li><a href=\"/view?id=" + imgid() + "\">" + imgid() + "</a></li>" ???} ???io.WriteString(w, "<html><body><ol>"+listHtml+"</ol></body></html>")}func init() { //main函数之前执行 ???fmt.Println("init-----")}func safeHandler(fn http.HandlerFunc) http.HandlerFunc { //异常的处理 ???return func(w http.ResponseWriter, r *http.Request) { ???????defer func() { ???????????if e, ok := recover().(error); ok { ???????????????http.Error(w, err.Error(), http.StatusInternalServerError) ???????????????log.Println("WARN: panic in %v - %v", fn, e) ???????????????log.Println(string(debug.Stack())) ???????????} ???????}() ???????fn(w, r) ???}}//处理静态资源func staticDirHandler(mux *http.ServeMux, prefix string, staticDir string, flags int) { ???mux.HandleFunc(prefix, func(w http.ResponseWriter, r *http.Request) { ???????file := staticDir + r.URL.Path[len(prefix)-1:] ???????if (flags & ListDir) == 0 { ???????????if exists := isExists(file); !exists { ???????????????http.NotFound(w, r) ???????????????return ???????????} ???????} ???????http.ServeFile(w, r, file) ???})}func main() { ???mux := http.NewServeMux() ???staticDirHandler(mux, "/assets/", "./public", 0) ???http.HandleFunc("/", safeHandler(listHandler)) ???http.HandleFunc("/view", safeHandler(viewHandler)) ???http.HandleFunc("/upload", safeHandler(uploadHandler)) ???err := http.ListenAndServe(":8080", nil) ???if err != nil { ???????log.Fatal("ListenAndServe: ", err.Error()) ???}}go ?文件上传
原文地址：https://www.cnblogs.com/yaowen/p/8478193.html