20200728-直接提取壓縮包里的文件

一 使用背景：

通過Http 請求下載一個壓縮的文件到伺服器記憶體中（重點：不用保存到本地），然後通過代碼直接提取壓縮包的文件

二 實現思路：(註：需要提前安裝 ICSharpCode.SharpZipLib.dll)

1 通過Http請求下載壓縮文件到伺服器的記憶體中

2 讀取記憶體中壓縮的包的流(註意先將:Stream 轉換成MemoryStream)

3 通過ICSharpCode.SharpZipLib.Zip.dll的ZipFile方法將壓縮包的MemoryStream 註入

4 通過文件索引提取壓縮包里的文件流

5 保存上傳文件到指定位置

三 參考代碼:

 1         public string HttpDownloadFile(int tenantId, RequestHeaadModel heaadModel)
 2         {
 3             var dfsResultPath = string.Empty;
 4             var listDfsPath = new List<string>();
 5             try
 6             {
 7                 #region Http請求參數設置
 8                 ServicePointManager.Expect100Continue = false;
 9                 ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12 | SecurityProtocolType.Tls | SecurityProtocolType.Ssl3;
10                 ServicePointManager.ServerCertificateValidationCallback += (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) => true;
11                 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(heaadModel.ResquestParamUrl);
12                 request.Headers.Add("x-qys-accesstoken", heaadModel.Accesstoken);
13                 request.Headers.Add("x-qys-timestamp", "0");
14                 request.Headers.Add("x-qys-signature", heaadModel.Searect);
15                 request.ContentType = heaadModel.ContentType;
16                 request.Method = "GET";
17                 request.Timeout = 100000;
18                 request.Accept = "application/octet-stream";
19                 #endregion
20 
21                 #region 對響應的壓縮包解析
22                 using (WebResponse webRes = request.GetResponse())
23                 {
24                     #region  1 獲取響應的壓縮包文件流
25                     var length = (long)webRes.ContentLength;
26                     var response = webRes as HttpWebResponse;
27                     var stream = response.GetResponseStream();
28                     #endregion
29 
30                     #region 2   將壓縮包文件流程讀取到記憶體中
31                     var stmMemory = new MemoryStream();
32                     if (length == -1)
33                     {
34                         length = 1024;
35                     }
36                     var buffer = new byte[length];
37                     int i;
38                     while ((i = stream.Read(buffer, 0, buffer.Length)) > 0)
39                     {
40                         stmMemory.Write(buffer, 0, i);
41                     }
42                     #endregion
43 
44                     #region 3 迴圈讀取壓縮包的文件
45                     var zipFile_ = new ICSharpCode.SharpZipLib.Zip.ZipFile(stmMemory);
46                     int count = int.Parse(zipFile_.Count.ToString());//獲取文件個數
47                     for (int j = 0; j < count; j++)
48                     {
49                         var tempSteam = zipFile_.GetInputStream(long.Parse($"{i}"));//壓縮包里的文件索引
50                         var stmMemory2 = new MemoryStream();
51                         var buffer2 = new byte[zipFile_[i].Size];
52                         int m;
53                         //將單個文件的文件流讀取到記憶體中
54                         while ((m = tempSteam.Read(buffer2, 0, buffer2.Length)) > 0)
55                         {
56                             stmMemory2.Write(buffer2, 0, m);
57                         }
58                         stmMemory2.Seek(0, SeekOrigin.Begin);
59                         var dfsItem = new DfsItem("TenantBaseFile", zipFile_[i].Name,
60                             stmMemory2, tenantId);
61                         var dfsPath = Dfs.Store(dfsItem);
62 
63                         Logger.Debug($"下載背調文件地址：{dfsPath.ToString()}");
64                         listDfsPath.Add(dfsPath.ToString());
65                         stmMemory2.Close();
66                         stmMemory2.Flush();
67                     }
68                     #endregion
69                     stmMemory.Close();
70                     stmMemory.Flush();
71                 }
72                 #endregion
73             }
74             catch (Exception ex)
75             {
76                 Logger.Debug($"下載報告異常：異常信息：{ex.Message}，堆棧信息：{ex.StackTrace}");
77             }
78 
79             return string.Join(",", listDfsPath);
80         }