/ rest

Azure Storage Table - Query Tables

Windows Azure Storage的Service第三方存取是採用REST API的方式,至於Windows Azure Storage Service跟REST爾後會再有文章特別介紹。

欲透過REST API方式抓取自己Azure Storage上有哪些table,有幾點必須要知道:

  • HTTP Method:GET
  • Request URI:http://myaccount.table.core.windows.net/Tables。myaccount部分為自己的storage name,或是從azure管理介面,不論是網頁版還是MMC,亦可直接取得Table URL。
  • Header部分:Authorization, Date or x-ms-date, x-ms-version。
其中比較麻煩的便是header的部分,主要程式碼如下:

var account = “myaccount”;

HttpWebRequest httpWebRequest =

(HttpWebRequest)HttpWebRequest.Create(uri);

httpWebRequest.Method = “GET”;

httpWebRequest.ContentLength = 0;

httpWebRequest.Headers.Add(“x-ms-date”, DateTime.UtcNow.ToString(“R”, CultureInfo.InvariantCulture));

var sharedKey = Convert.FromBase64String(“your primary access key”);

var resource = httpWebRequest.RequestUri.PathAndQuery;

if (resource.Contains(“?”))

{

resource = resource.Substring(0, resource.IndexOf(“?”));

}

string stringToSign = string.Format(“{0}\n/{1}{2}”, httpWebRequest.Headers[“x-ms-date”], account, resource);

var hasher = new HMACSHA256(sharedKey);

string signedSignature = Convert.ToBase64String(hasher.ComputeHash(Encoding.UTF8.GetBytes(stringToSign)));

string authorizationHeader = string.Format(“{0} {1}:{2}”, “SharedKeyLite”, account, signedSignature);

httpWebRequest.Headers.Add(“Authorization”, authorizationHeader);

//不能加

//httpWebRequest.Headers.Add(“x-ms-version”, “2009-09-19”);

httpWebRequest.ContentType = “application/xml”;

var response = request.GetResponse();

比較詭異的是加了x-ms-version的header便會無法正常取得response。

參考連結:

http://blog.einbu.no/2009/08/authenticating-against-azure-table-storage/

http://msdn.microsoft.com/en-us/library/dd179405.aspx