微信小程序基于腾讯云对象存储的图片上传

2018-06-22 07:57:18来源：未知阅读 ()

在使用腾讯云对象存储之前，公司一直使用的是传统的FTP的上传模式，而随着用户量的不断增加，FTP所暴露出来的问题也越来越多，1.传输效率低，上传速度慢。2.时常有上传其他文件来攻击服务器，安全上得不到保障。所以我们在经过慎重考虑觉得使用第三方的云存储服务。

在最开始的时候我们在腾讯云与阿里云中选择，最终我们选择腾讯云，腾讯云在文件上传用时方面的性能比较突出，文件越大表现越好；在下载用时方面表现略优于阿里云；文件删除用时方面总体速度略逊于，但在不同大小文件删除用时上都比较稳定。当然这与我们主要用于开发微信小程序是有着密切的关系。

在我们酷客多小程序使用腾讯云对象存储的时候除了直接使用 API 接口外，COS 提供了丰富多样的 SDK 给我们使用，可是在他提供的SDK中并没有发现我们Asp.net相关的SDK

在一番百度和一顿操作终于让我找到啦！看到没，只能说隐藏的真深，而且还是历史版本的，但是不管怎么样我们还是找到啦

找到C#的SDK,下载下来（附上C#版本SDK的下载地址 C# SDK github项目下载地址）然后按照SDK中提供的方法，就可以成功上传！

然而并没有这么简单，当我们使用SDK中的方法的时候发现，SDK中的方法只适用于，绝对路径地址的文件上传！也就是并不满足我们ASP.Net中使用文件域上传文件。此时我们只有对方法进行改造！

附上改造过后代码：

        /// <summary>
        /// 文件流上传
        /// 说明: 酷客多小程序
        /// 其中分片上传使用SliceUploadInit SliceUploadData SliceUploadFinihs
        /// </summary>
        /// <param name="bucketName">bucket名称</param>
        /// <param name="remotePath">远程文件路径</param>
        /// <param name="localPath">本地文件路径</param>
        /// <param name="parameterDic">参数Dictionary</param>
        /// <returns></returns>
        public string UploadFile(string bucketName, string remotePath, Stream file, string filename,Dictionary<string, string> parameterDic = null)
        {
            if (remotePath.EndsWith("/"))
            {
                return constructResult(ERRORCode.ERROR_CODE_PARAMETER_ERROE, "file path can not end with '/'");
            }

            string bizAttribute = "";
            if (parameterDic != null && parameterDic.ContainsKey(CosParameters.PARA_BIZ_ATTR))
                bizAttribute = parameterDic[CosParameters.PARA_BIZ_ATTR];

            int insertOnly = 1;
            if (parameterDic != null && parameterDic.ContainsKey(CosParameters.PARA_INSERT_ONLY))
            {
                try
                {
                    insertOnly = Int32.Parse(parameterDic[CosParameters.PARA_INSERT_ONLY]);
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.Message);
                    return constructResult(ERRORCode.ERROR_CODE_PARAMETER_ERROE, "parameter insertOnly value invalidate");
                }
            }
            return Upload(bucketName, remotePath, file, filename, bizAttribute, insertOnly);

        }

        /// <summary>
        /// 单个文件上传
        /// 说明: 酷客多小程序
        /// <param name="bucketName">bucket名称</param>
        /// <param name="remotePath">远程文件路径</param>
        /// <param name="localPath">本地文件路径</param>
        /// <param name="biz_attr">biz_attr属性</param>
        /// <param name="insertOnly">同名文件是否覆盖</param>
        /// <returns></returns>
        public string Upload(string bucketName, string remotePath, Stream file,string filename,
                                  string bizAttribute = "", int insertOnly = 1)
        {

            var url = generateURL(bucketName, remotePath);
            var sha1 = SHA1.GetFileSHA1(file);
            var data = new Dictionary<string, object>();
            data.Add("op", "upload");
            data.Add("sha", sha1);
            data.Add("biz_attr", bizAttribute);
            data.Add("insertOnly", insertOnly);

            var expired = getExpiredTime();
            var sign = Sign.Signature(appId, secretId, secretKey, expired, bucketName);
            var header = new Dictionary<string, string>();
            header.Add("Authorization", sign);


            return httpRequest.SendRequest(url, ref data, HttpMethod.Post, ref header, timeOut, file, filename);
        }

       #region 直接上传文件流
       public string SendRequest(string url, ref Dictionary<string, object> data, HttpMethod requestMethod,
       ref Dictionary<string, string> header, int timeOut, Stream file,string filename, long offset = -1, int sliceSize = 0)
        {
            try
            {
                //Console.WriteLine("url:" + url);
                System.Net.ServicePointManager.Expect100Continue = false;
                if (requestMethod == HttpMethod.Get)
                {
                    var paramStr = "";
                    foreach (var key in data.Keys)
                    {
                        paramStr += string.Format("{0}={1}&", key, HttpUtility.UrlEncode(data[key].ToString()));
                    }
                    paramStr = paramStr.TrimEnd('&');
                    url += (url.EndsWith("?") ? "&" : "?") + paramStr;
                }

                request = (HttpWebRequest)HttpWebRequest.Create(url);
                request.Accept = CosDefaultValue.ACCEPT;
                request.KeepAlive = true;
                request.UserAgent = CosDefaultValue.USER_AGENT_VERSION;
                request.Timeout = timeOut;
                foreach (var key in header.Keys)
                {
                    if (key == "Content-Type")
                    {
                        request.ContentType = header[key];
                    }
                    else
                    {
                        request.Headers.Add(key, header[key]);
                    }
                }
                if (requestMethod == HttpMethod.Post)
                {
                    request.Method = requestMethod.ToString().ToUpper();
                    var memStream = new MemoryStream();
                    if (header.ContainsKey("Content-Type") && header["Content-Type"] == "application/json")
                    {
                        var json = JsonConvert.SerializeObject(data);
                        var jsonByte = Encoding.GetEncoding("utf-8").GetBytes(json.ToString());
                        memStream.Write(jsonByte, 0, jsonByte.Length);
                    }
                    else
                    {
                        var boundary = "---------------" + DateTime.Now.Ticks.ToString("x");
                        var beginBoundary = Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
                        var endBoundary = Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
                        request.ContentType = "multipart/form-data; boundary=" + boundary;

                        var strBuf = new StringBuilder();
                        foreach (var key in data.Keys)
                        {
                            strBuf.Append("\r\n--" + boundary + "\r\n");
                            strBuf.Append("Content-Disposition: form-data; name=\"" + key + "\"\r\n\r\n");
                            strBuf.Append(data[key].ToString());
                        }
                        var paramsByte = Encoding.GetEncoding("utf-8").GetBytes(strBuf.ToString());
                        memStream.Write(paramsByte, 0, paramsByte.Length);

                        memStream.Write(beginBoundary, 0, beginBoundary.Length);


                        var fileStream = file;

                        const string filePartHeader =
                            "Content-Disposition: form-data; name=\"fileContent\"; filename=\"{0}\"\r\n" +
                            "Content-Type: application/octet-stream\r\n\r\n";
                        var headerText = string.Format(filePartHeader, filename);
                        var headerbytes = Encoding.UTF8.GetBytes(headerText);
                        memStream.Write(headerbytes, 0, headerbytes.Length);

                        if (offset == -1)
                        {
                            var buffer = new byte[1024];
                            int bytesRead;
                            while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
                            {
                                memStream.Write(buffer, 0, bytesRead);
                            }
                        }
                        else
                        {
                            var buffer = new byte[sliceSize];
                            int bytesRead;
                            fileStream.Seek(offset, SeekOrigin.Begin);
                            bytesRead = fileStream.Read(buffer, 0, buffer.Length);
                            memStream.Write(buffer, 0, bytesRead);
                        }
                        fileStream.Close();

                        memStream.Write(endBoundary, 0, endBoundary.Length);
                    }
                    request.ContentLength = memStream.Length;
                    var requestStream = request.GetRequestStream();
                    memStream.Position = 0;
                    var tempBuffer = new byte[memStream.Length];
                    memStream.Read(tempBuffer, 0, tempBuffer.Length);
                    memStream.Close();

                    requestStream.Write(tempBuffer, 0, tempBuffer.Length);
                    requestStream.Close();

                    //Console.WriteLine(strBuf.ToString());
                }

                //Console.WriteLine(request.ContentType.ToString());


                var response = request.GetResponse();
                using (var s = response.GetResponseStream())
                {
                    var reader = new StreamReader(s, Encoding.UTF8);
                    return reader.ReadToEnd();
                }
            }
            catch (WebException we)
            {
                if (we.Status == WebExceptionStatus.ProtocolError)
                {
                    using (var s = we.Response.GetResponseStream())
                    {
                        var reader = new StreamReader(s, Encoding.UTF8);
                        return reader.ReadToEnd();
                    }
                }
                else
                {
                    throw we;
                }
            }
            catch (Exception e)
            {
                throw e;
            }
        }