public Crawler Fetch()
{
if (!IsExternalIPAddress(this.SourceUrl))
{
State = "INVALID_URL";
return(this);
}
var request = HttpWebRequest.Create(this.SourceUrl) as HttpWebRequest;
using (var response = request.GetResponseAsync().Result as HttpWebResponse)
{
if (response.StatusCode != HttpStatusCode.OK)
{
State = "Url returns " + response.StatusCode + ", " + response.StatusDescription;
return(this);
}
if (response.ContentType.IndexOf("image") == -1)
{
State = "Url is not an image";
return(this);
}
ServerUrl = PathFormatter.Format(Path.GetFileName(this.SourceUrl), Config.GetString("catcherPathFormat"), _userid);
if (!ServerUrl.StartsWith("/upFiles"))
{
State = "Url is invalid!";
return(this);
}
var savePath = _context.MapPath(ServerUrl);
var folder = Path.GetDirectoryName(savePath);
if (!Directory.Exists(folder))
{
Directory.CreateDirectory(folder);
}
try
{
var stream = response.GetResponseStream();
var reader = new BinaryReader(stream);
byte[] bytes;
using (var ms = new MemoryStream())
{
byte[] buffer = new byte[4096];
int count;
while ((count = reader.Read(buffer, 0, buffer.Length)) != 0)
{
ms.Write(buffer, 0, count);
}
bytes = ms.ToArray();
}
File.WriteAllBytes(savePath, bytes);
State = "SUCCESS";
}
catch (Exception e)
{
State = "抓取错误：" + e.Message;
}
return(this);
}
}
private bool CanLogin(object parameter)
{
bool validServerUrl =
!string.IsNullOrWhiteSpace(ServerUrl) &&
Uri.IsWellFormedUriString(ServerUrl, UriKind.Absolute) &&
ServerUrl.StartsWith("http", StringComparison.InvariantCultureIgnoreCase);
return
(validServerUrl &&
!string.IsNullOrWhiteSpace(Username) &&
!string.IsNullOrWhiteSpace(_getPasswordDelegate?.Invoke()));
}