Golang错误处理相关

错误处理
一个简单的文件打开操作demo

	_, err := os.OpenFile(filename, os.O_EXCL|os.O_CREATE, 0666)
	if err != nil {
		if pahErr, ok := err.(*os.PathError); !ok {
			panic(err)
		}else{
			fmt.Printf("%s %s %s\n",pahErr.Path,pahErr.Op,pahErr.Err)
		}
		return
	}

针对返回任务的错误信息进行了打印

fmt.Printf("%s %s %s\n",pahErr.Path,pahErr.Op,pahErr.Err)

统一实现任务处理的demo

type appHandler func(w http.ResponseWriter, req *http.Request) error

// errWrapper 错误处理
func errWrapper(handler appHandler) func(http.ResponseWriter, *http.Request){
	return func(w http.ResponseWriter, req *http.Request){
		err := handler(w, req)
		if err != nil {
			code := http.StatusOK
			switch {
			case os.IsNotExist(err):
				code = http.StatusNotFound
			case os.IsPermission(err):
				code = http.StatusForbidden
			default:
				code = http.StatusInternalServerError
			}
			http.Error(w, http.StatusText(code), code)
		}
	}
}
// HandleFileListing 
func HandleFileListing(w http.ResponseWriter, req *http.Request) error{
	path := req.URL.Path[len("/list/"):]
	file, err := os.Open(path)
	if err != nil {
		return err
	}
	defer file.Close()

	all, err := ioutil.ReadAll(file)
	if err != nil {
		return err
	}
	w.Write(all)
	return nil
}

panic兜底操作— recover

	defer func(){
		r := recover()
		if err, ok := r.(error); ok {
			fmt.Println(err)
		} else {
			panic(err)
		}
	}()