Go文件上传下载

使用io包和net包实现基于http的文件上传下载

func handleUpload (w http.ResponseWriter, request *http.Request) {

    //文件上传只允许POST方法

    if request.Method != http.MethodPost {

        w.WriteHeader(http.StatusMethodNotAllowed)

        _, _ = w.Write([]byte("Method not allowed"))

        return

    }

    //从表单中读取文件

    file, fileHeader, err := request.FormFile("file")

    if err != nil {

        _, _ = io.WriteString(w, "Read file error")

        return

    }

    //defer 结束时关闭文件

    defer file.Close()

    log.Println("filename: " + fileHeader.Filename)

    //创建文件

    newFile, err := os.Create( "./" + fileHeader.Filename)

    if err != nil {

        _, _ = io.WriteString(w, "Create file error")

        return

    }

    //defer 结束时关闭文件

    defer newFile.Close()

    //将文件写到本地

    _, err = io.Copy(newFile, file)

    if err != nil {

        _, _ = io.WriteString(w, "Write file error")

        return

    }

    _,_ = io.WriteString(w, "Upload success")

func handleDownload (w http.ResponseWriter, request *http.Request) {
    //文件上传只允许GET方法
    if request.Method != http.MethodGet {
        w.WriteHeader(http.StatusMethodNotAllowed)
        _, _ = w.Write([]byte("Method not allowed"))
        return
    }
    //文件名
    filename := request.FormValue("filename")
    if filename == "" {
        w.WriteHeader(http.StatusBadRequest)
        _, _ = io.WriteString(w, "Bad request")
        return
    }
    log.Println("filename: " + filename)
    //打开文件
    file, err := os.Open(BaseUploadPath + "/" + filename)
    if err != nil {
        w.WriteHeader(http.StatusBadRequest)
        _, _ = io.WriteString(w, "Bad request")
        return
    }
    //结束后关闭文件
    defer file.Close()

    //设置响应的header头
    w.Header().Add("Content-type", "application/octet-stream")
    w.Header().Add("content-disposition", "attachment; filename=\""+filename+"\"")
    //将文件写至responseBody
    _, err = io.Copy(w, file)
    if err != nil {
        w.WriteHeader(http.StatusBadRequest)
        _, _ = io.WriteString(w, "Bad request")
        return
    }
}