使用HttpWebRequest时保持会话

Question

在我的项目中，我使用C＃应用程序客户端和tomcat6 Web应用程序服务器。 我在C＃客户端写了这个片断：

public bool isServerOnline() 
{ 
     Boolean ret = false; 

     try 
     { 
      HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(VPMacro.MacroUploader.SERVER_URL); 
      req.Method = "HEAD"; 
      req.KeepAlive = false; 
      HttpWebResponse resp = (HttpWebResponse)req.GetResponse(); 
      if (resp.StatusCode == HttpStatusCode.OK) 
      { 
       // HTTP = 200 - Internet connection available, server online 
       ret = true; 
      } 
      resp.Close(); 
      return ret; 

     } 
     catch (WebException we) 
     { 
      // Exception - connection not available 
      Log.e("InternetUtils - isServerOnline - " + we.Status); 
      return false; 
     } 
} 

每次我调用这个方法，我在服务器端得到一个新的会话。 我想这是因为我应该在我的客户端使用HTTP cookie。但我不知道该怎么做，你能帮助我吗？

Answer 1

您必须使用CookieContainer并保持呼叫之间的实例。

private CookieContainer cookieContainer = new CookieContainer(); 
public bool isServerOnline() 
{ 
     Boolean ret = false; 

     try 
     { 
      HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(VPMacro.MacroUploader.SERVER_URL); 
      req.CookieContainer = cookieContainer; // <= HERE 
      req.Method = "HEAD"; 
      req.KeepAlive = false; 
      HttpWebResponse resp = (HttpWebResponse)req.GetResponse(); 
      if (resp.StatusCode == HttpStatusCode.OK) 
      { 
       // HTTP = 200 - Internet connection available, server online 
       ret = true; 
      } 
      resp.Close(); 
      return ret; 

     } 
     catch (WebException we) 
     { 
      // Exception - connection not available 
      Log.e("InternetUtils - isServerOnline - " + we.Status); 
      return false; 
     } 
}