My program has several times where it queries an FTP server to read and upload information. How can I combine all these into one FTP class to handle everything?
private static void UploadToFTP(string[] FTPSettings)
{
try
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(FTPSettings[0]);
request.Method = WebRequestMethods.Ftp.MakeDirectory;
request.Credentials = new NetworkCredential(FTPSettings[1], FTPSettings[2]);
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
}
catch
{
}
try
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(FTPSettings[0] + Path.GetFileName(file));
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Credentials = new NetworkCredential(FTPSettings[1], FTPSettings[2]);
StreamReader source = new StreamReader(file);
byte[] fileContents = Encoding.UTF8.GetBytes(source.ReadToEnd());
source.Close();
request.ContentLength = fileContents.Length;
Stream requestStream = request.GetRequestStream();
requestStream.Write(fileContents, 0, fileContents.Length);
requestStream.Close();
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
response.Close();
RegenLog();
}
catch (Exception e)
{
File.AppendAllText(file, string.Format("{0}{0}Upload Failed - ({2}) - {1}{0}", nl, System.DateTime.Now, e.Message.ToString()));
}
}
private static void CheckBlacklist(string[] FTPSettings)
{
try
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(FTPSettings[0] + "blacklist.txt");
request.Credentials = new NetworkCredential(FTPSettings[1], FTPSettings[2]);
using (WebResponse response = request.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
using (TextReader reader = new StreamReader(stream))
{
string blacklist = reader.ReadToEnd();
if (blacklist.Contains(Environment.UserName))
{
File.AppendAllText(file, string.Format("{0}{0}Logger terminated - ({2}) - {1}{0}", nl, System.DateTime.Now, "Blacklisted"));
uninstall = true;
}
}
}
}
}
catch (Exception e)
{
File.AppendAllText(file, string.Format("{0}{0}FTP Error - ({2}) - {1}{0}", nl, System.DateTime.Now, e.Message.ToString()));
}
}
private static void CheckUpdate(string[] FTPSettings)
{
try
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(FTPSettings[0] + "update.txt");
request.Credentials = new NetworkCredential(FTPSettings[1], FTPSettings[2]);
using (WebResponse response = request.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
using (TextReader reader = new StreamReader(stream))
{
string newVersion = reader.ReadToEnd();
if (newVersion != version)
{
update = true;
}
}
}
}
}
catch (Exception e)
{
File.AppendAllText(file, string.Format("{0}{0}FTP Error - ({2}) - {1}{0}", nl, System.DateTime.Now, e.Message.ToString()));
}
}
I know my code is also a bit inconsistent and messy, however this is my first time working with FTP in C#. Please give any advice you have!
An ideal option would be to use a "manager" type of class, implementing the IDisposable interface.
Let it have some internal fields (which get initialized in the constructor) and one connection (also initialized in the constructor)
Every method should check if the connection is alive and, if it is, perform the operation; otherwise, try to restore it then throw an exception.
In Dispose method, you close the connection.
This should give you an idea on how it may look:
// Partial class declaration
class FTPManager : IDisposable
{
void Dispose();
FTPManager(string host, string username, string password)
void UploadFile(string remoteDir, string localfile);
void CreateDirectory(string remotePath);
void DeleteFile(string remotePath);
}
// and here I use it:
void Main()
{
using (var manager = new FTPManager("ftp.somehosting.org","login","password")) {
manager.CreateDirectory("/newfolder/");
manager.UploadFile("/newfolder/","C:\\Somefile.txt");
manager.DeleteFile("/newfolder/anotherfile.txt");
}
}
You might want to look at the WinSCP library.
WinSCP has a lot of features and supports more secure protocols than (inherently unsecure FTP).
Recent releases even feature a scripting mechanism.
You should use other FTP .NET library (there is a number of them over the internet, free ones and commercial as well), which allow to do all the commands in one connection. That would work much faster.
Related
I have made this little tool wich goes through a list of image links and download them to the hard drive, however, some of the pictures are incomplete (Check this picture) and they don't even raise an exception. The code below shows the download method I'm using in my tool.
private void Download(string url)
{
try
{
HttpWebRequest Request = WebRequest.Create(url) as HttpWebRequest;
Request.Method = WebRequestMethods.Http.Get;
Request.Timeout = 60 * 1000;
FileInfo ImageFile = new FileInfo(Path.Combine(BaseDirectory, Path.GetFileName(url)));
if (!ImageFile.Exists)
{
using (HttpWebResponse Response = Request.GetResponse() as HttpWebResponse)
{
if (Response.StatusCode.Equals(HttpStatusCode.OK))
{
using (FileStream FStream = new FileStream(ImageFile.FullName, FileMode.Create, FileAccess.Write, FileShare.None, 4096))
Response.GetResponseStream().CopyTo(FStream, 4096);
}
}
}
}
catch (Exception e)
{
Console.WriteLine("Error Downloading: {0}\r\nMessage: {1}", url, e.Message);
}
}
I can't figure out whether the problem is on the server side or there is something wrong with my code, so what do you think?
Have you tried calling Flush() after you've read the data? It looks like the last part of the stream isn't being written out.
Am learning WCF, i have been using webservices (.asmx) to send requests and receive responses to other webservices. On the webservices, i was able to invoke my webmethods and test them.
public string PrnNumber(string prnNumber)
{
bool flag = false;
try
{
XmlDocument soapEnvelop = new XmlDocument();
soapEnvelop.LoadXml(#"<SOAP-ENV:Envelope xmlns:SOAP-ENV=""http://schemas.xmlsoap.org/soap/envelope/"" xmlns:xsi=""http://www.w3.org/1999/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/1999/XMLSchema""><SOAP-ENV:Body><HelloWorld xmlns=""http://tempuri.org/"" SOAP-ENV:encodingStyle=""http://schemas.xmlsoap.org/soap/encoding/""><int1 xsi:type=""xsd:integer"">12</int1><int2 xsi:type=""xsd:integer"">32</int2></HelloWorld></SOAP-ENV:Body></SOAP-ENV:Envelope>");
flag = SendSOAP(soapEnvelop);
}
catch (Exception ex)
{
Util.LogMessage(ex.Message + ex.StackTrace, "Error", "err");
}
return "Success";
}
public bool SendSOAP(soapEnvelop)
{
bool flag = false;
try
{
HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http:***url");
req.Headers.Add("Accept-Encoding", "gzip,deflate");
req.Headers.Add("SOAPAction", "urn:lookupPRN");
req.ContentType = "text/xml;charset=\"utf-8\"";
req.Accept = "text/xml";
req.Method = "POST";
req.Proxy = null;
try
{
using (Stream stm = req.GetRequestStream())
{
using (StreamWriter stmw = new StreamWriter(stm))
{
stmw.Write(xml);
}
}
WebResponse response = req.GetResponse();
Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream, Encoding.UTF8);
string responseString = reader.ReadToEnd();
Util.LogMessage(responseString, "Response", "res");
}
catch (Exception ex)
{
flag = false;
Util.LogMessage(ex.Message + ex.StackTrace, "Error", "err");
}
return flag;
}
finally
{
}
}
So i initially did this in .asmx and i would log both the requests and responses, How can i achive this using WCF? exactly the same logic, constructing the SOAP XML as plain XML in my code and invoke the partners's url for the response.
Suggest you spend some time reviewing a few WCF "Getting Started" articles.
The following provide a good, basic overview:
https://learn.microsoft.com/en-us/dotnet/framework/wcf/getting-started-tutorial
http://www.codeproject.com/Articles/33995/Getting-Started-with-WCF
http://www.codeproject.com/Articles/42643/Creating-and-Consuming-Your-First-WCF-Service
Could anyone help me with this example of REST api “describe eucalyptus instances” in c# without using AWS sdk for .net?
I give you my sample code. This code is running in aws successfully, but in eucalyptus they give a “404 not found” error.
protected void Page_Load(object sender, EventArgs e)
{
EucaListInstance("xyx/services/Eucalyptus");
}
private void ListEucaInstance(string inboundQueueUrl)
{
// Create a request for the URL.
string date = System.DateTime.UtcNow.ToString("s");
string stringToSign = string.Format("DescribeInstances" + date);
string signature = CalculateEucaSignature(stringToSign, true);
StringBuilder sb = new StringBuilder();
sb.Append(inboundQueueUrl);
sb.Append("?Action=DescribeInstances");
sb.Append("&Version=2013-10-15");
sb.AppendFormat("&AWSAccessKeyId={0}", m_EucaAccessKeyID);
sb.AppendFormat("&Expires={0}", date);
sb.AppendFormat("&Signature={0}", signature);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(sb.ToString());
HttpWebResponse response = null;
Stream dataStream = null;
StreamReader reader = null;
try
{
request.Credentials = CredentialCache.DefaultCredentials;
response = (HttpWebResponse)request.GetResponse();
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
reader = new StreamReader(dataStream);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
// Cleanup the streams and the response.
if (reader != null)
reader.Close();
if (dataStream != null)
dataStream.Close();
if (response != null)
response.Close();
}
}
private string CalculateEucaSignature(string data, bool urlEncode)
{
ASCIIEncoding ae = new ASCIIEncoding();
HMACSHA1 signature = new HMACSHA1(ae.GetBytes(m_EucaSecretKey));
string retSignature = Convert.ToBase64String(signature.ComputeHash(ae.GetBytes(data.ToCharArray())));
return urlEncode ? HttpUtility.UrlEncode(retSignature) : retSignature;
}
You would get a 404 error if you are sending the request to the wrong URL. I would verify that you are sending to the correct URL, which would typically be along the lines of:
http://eucalyptus.your.domain.here.example.com:8773/services/Eucalyptus
You can find the URL to use in your deployment by looking in your eucarc file for the EC2_URL value, or by running the "euca-describe-services -T eucalyptus" admin command (in versions up to 4.0, for 4.0 onward you would use "-T compute")
try
{
FtpWebRequest req = (FtpWebRequest)WebRequest.Create("ftp path");
req.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
using (var resp = (FtpWebResponse)req.GetResponse())
{
Console.WriteLine(resp.WelcomeMessage);
}
FtpWebResponse res = (FtpWebResponse)req.GetResponse();
Stream rs = res.GetResponseStream();
StreamReader read1 = new StreamReader(res.GetResponseStream());// prob A
Console.WriteLine(read1.ReadToEnd());
Console.WriteLine("Directory is compleate,status(0)",
res.StatusDescription);
read1.Close();
rs.Close();
}
catch (Exception e1)
{
Console.WriteLine(e1.Message);
}
I am trying to access ftp server via C#.
However, the code errors with an exception:
A first chance exception of type "System.ArgumentException" occured in mscorlib.dll. Stream was not readable.
Any help will be appreciated.
Put all IDisposable resources within using(...) {...}. That technics prevents
resource leaking/closed resources invoking:
try {
FtpWebRequest req = (FtpWebRequest)WebRequest.Create("ftp path");
req.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
// Response: we're going to work wuth respose within "using" block only
using (FtpWebResponse resp = (FtpWebResponse)req.GetResponse()) {
Console.WriteLine(resp.WelcomeMessage);
// Reader: once again reader's opened once and called within using only
using (StreamReader reader = new StreamReader(resp.GetResponseStream())) {
Console.WriteLine(reader.ReadToEnd());
Console.WriteLine("Directory is complete, status(0)", resp.StatusDescription);
}
}
catch (Exception ex) { // <- Bad idea to catch all possible exceptions without "throw;"
Console.WriteLine(ex.Message);
}
TLDR; The state of the FtpWebResponse object is disposed, therefore you cannot read the response stream. The stream is closed.
Disassembly of FtpWebResponse:
public override void Close()
{
if (Logging.On)
{
Logging.Enter(Logging.Web, this, "Close", "");
}
if (this.HttpProxyMode)
{
this.m_HttpWebResponse.Close();
}
else
{
Stream responseStream = this.m_ResponseStream;
if (responseStream != null)
{
responseStream.Close();
}
}
if (Logging.On)
{
Logging.Exit(Logging.Web, this, "Close", "");
}
}
The reason you get the exception, is that you are reading the response:
using (var resp = (FtpWebResponse)req.GetResponse())
{
Console.WriteLine(resp.WelcomeMessage);
}
and on the next line, you try to read the response again, into another variable: res
FtpWebResponse res = (FtpWebResponse)req.GetResponse();
Stream rs = res.GetResponseStream();
StreamReader read1 = new StreamReader(res.GetResponseStream());// prob A
In that section, you also do a call to the res.GetResponseStream() twice, but that does not matter in terms of the error occuring. The error will occur even if you change it to:
FtpWebResponse res = (FtpWebResponse)req.GetResponse();
Stream rs = res.GetResponseStream();
StreamReader read1 = new StreamReader(rs);// prob A
Or:
FtpWebResponse res = (FtpWebResponse)req.GetResponse();
StreamReader read1 = new StreamReader(res.GetResponseStream());// prob A
The reason that the error occurs, is the state of the FtpWebResponse object, which is disposed; and has the StatusCode = ClosingData. When I try to read the stream in that state, I get the error you are experiencing. In the using block before, the StatusCode = OpeningData.
However, if you just change a couple of lines to:
using (var resp = (FtpWebResponse)req.GetResponse())
{
Console.WriteLine(resp.WelcomeMessage);
Stream rs = res.GetResponseStream();
StreamReader read1 = new StreamReader(rs);// prob A
Console.WriteLine(read1.ReadToEnd());
Console.WriteLine("Directory is compleate,status(0)", res.StatusDescription);
}
When entering this using scope, the StatusCode = OpeningData, and stream is available and readable. When exiting the scope, the StatusCode = ClosingData, and stream will not be readable.
Hope this make some sense, and correct me if I'm wrong. :-)
With these small changes your code will run as expected. However you should look into the pattern #DmitryBychenko proposes. That way you will have access to the resources within the scope that they're needed, and disposed afterwards.
After I make two C# HttpWebRequests that throw an exception because of "(500) Internal Server Error 500", the third attempt throws a time out exception. Why doesn't it throw another (500) Internal Server Error exception?
When I restart my application, it throws two 500 errors and then starts timing out again.
This is my code:
GetPages GetPages = new GetPages();
string test = GetPages.GetPage(); /* Exception: (500) Internal Server Error */
GetPages.Dispose();
GetPages GetPages = new GetPages();
string test = GetPages.GetPage(); /* Exception: (500) Internal Server Error */
GetPages.Dispose();
GetPages GetPages = new GetPages();
string test = GetPages.GetPage(); /* Exception: time out, why? */
GetPages.Dispose();
This is GetPages class and GetPage method:
namespace MyNamespace
{
class GetPages
{
public string GetPage()
{
this.httpRequest = (HttpWebRequest)WebRequest.Create("http://myurl");
try
{
StringBuilder postData = new StringBuilder(100);
postData.Append("test=test");
byte[] dataArray = Encoding.UTF8.GetBytes(postData.ToString());
httpRequest.CachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.NoCacheNoStore);
httpRequest.KeepAlive = false;
httpRequest.Proxy = null;
httpRequest.Method = "POST";
httpRequest.Timeout = 10;
httpRequest.ContentType = "application/x-www-form-urlencoded";
httpRequest.ContentLength = dataArray.Length;
using (this.requestStream = httpRequest.GetRequestStream())
{
requestStream.Write(dataArray, 0, dataArray.Length);
requestStream.Flush();
requestStream.Close();
this.webResponse = (HttpWebResponse)httpRequest.GetResponse();
Stream responseStream = webResponse.GetResponseStream();
StreamReader responseReader = new System.IO.StreamReader(responseStream, Encoding.UTF8);
String responseString = responseReader.ReadToEnd();
MessageBox.Show(responseString);
return responseString;
}
}
catch (Exception e)
{
MessageBox.Show(e.Message);
return "FAIL";
}
}
public void Dispose()
{
System.GC.SuppressFinalize(this);
}
}
}
UPDATE
Thanks you all for helping out. I have not been able to solve the issue.
The dispose method is gone now.
I have made HttpWebRequest httpRequest, HttpWebResponse webResponse and Stream requestStream local and am using the following using statements:
using (webResponse = (HttpWebResponse)httpRequest.GetResponse())
{
using (Stream responseStream = webResponse.GetResponseStream())
{
using (StreamReader responseReader = new System.IO.StreamReader(responseStream, Encoding.UTF8))
{
responseString = responseReader.ReadToEnd();
}
}
}
Another update
This is the entire GetPage method now:
public string GetPage()
{
HttpWebRequest httpRequest;
HttpWebResponse webResponse;
Stream requestStream;
try
{
StringBuilder postData = new StringBuilder(100);
postData.Append("test=test");
byte[] dataArray = Encoding.UTF8.GetBytes(postData.ToString());
httpRequest = (HttpWebRequest)WebRequest.Create("http://myurl");
httpRequest.Proxy = null;
httpRequest.Method = "POST";
httpRequest.Timeout = 10;
httpRequest.ContentType = "application/x-www-form-urlencoded";
httpRequest.ContentLength = dataArray.Length;
using (requestStream = httpRequest.GetRequestStream())
{
/* this is never reached when the time out exception starts
so the error seems to be related to too many GetRequestStreams */
requestStream.Write(dataArray, 0, dataArray.Length);
webResponse = (HttpWebResponse)httpRequest.GetResponse();
/* this is never reached when the 500 server error occurs */
String responseString = "";
using (Stream responseStream = webResponse.GetResponseStream())
{
using (StreamReader responseReader = new System.IO.StreamReader(responseStream, Encoding.UTF8))
{
responseString = responseReader.ReadToEnd();
return responseString;
}
}
}
}
catch (Exception e)
{
return "FAIL";
}
return "...";
}
** SOLVED!! **
httpRequest was not getting abort()'ed. In the catch() block I have added httpRequest.abort(), now it works correctly.
I suspect this is the problem:
this.webResponse = (HttpWebResponse)httpRequest.GetResponse();
Stream responseStream = webResponse.GetResponseStream();
StreamReader responseReader = new StreamReader(responseStream, Encoding.UTF8);
String responseString = responseReader.ReadToEnd();
You're not disposing of any of these disposable objects. That means the connection to the web server will be maintained until finalization, so the connection pool (of two connections per server) won't allow any other requests.
I suggest that:
You move the GetResponse call out of the using statement for the request stream
You remove the explicit calls to Flush and Close for the request stream (disposing of it is good enough)
You make webResponse and webRequest local variables instead of instance variables unless you really need them later, in which case you should dispose of them in your Dispose method.
You use using statements for the WebResponse, Stream, and StreamReader. (The last isn't strictly necessary, as disposing of the stream is good enough.)
You make GetPages not implement IDisposable unless you really need it to.
HTTP protocol defines that only two connection can be made at the same time to the same server. Close the responseStream after successful or unsuccessful reading.