我有这个源代码：
public static void FTP_SERVER()
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/");
request.Method = WebRequestMethods.Ftp.ListDirectory;
request.Credentials = new NetworkCredential("myusername", "mypassword");
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream);
ArrayList directories = new ArrayList();
while (!reader.EndOfStream)
{
String directory = reader.ReadLine();
int i = 0;
for (i = 0; i < directories.Count && Convert.ToInt32(directory) > Convert.ToInt32(directories[i] + ""); i++);
directories.Insert(i, directory);
}
String[] agents = Crawler.CrawlerDbUtils.getAllAgentIDs();
reader.Close();
response.Close();
int j = 0;
for (int i = 0; i < directories.Count; i++)
{
try
{
while ((j < agents.Length) && (Convert.ToInt32(agents[j]) < Convert.ToInt32(directories[i] + "")))
{
try
{
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + agents[j]);
request.Method = WebRequestMethods.Ftp.MakeDirectory;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
response.Close();
}
catch (Exception exception)
{ }
j++;
}
if (Convert.ToInt32(agents[j]) == Convert.ToInt32(directories[i] + ""))
{
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + directories[i] + "/");
request.Method = WebRequestMethods.Ftp.ListDirectory;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
reader = new StreamReader(responseStream);
ArrayList files = new ArrayList();
while (!reader.EndOfStream)
{
String file = reader.ReadLine();
int q = 0;
for (q = 0; q < files.Count && file.CompareTo(files[q] + "") > 0; q++) ;
files.Insert(q, file);
}
reader.Close();
response.Close();
String[] dbFiles = Crawler.CrawlerDbUtils.getAllPictures(directories[i] + "");
int r = 0;
for (int q = 0; q < files.Count; q++)
{
while ((r < dbFiles.Length) && ((dbFiles[r] + "").CompareTo(files[q] + "") < 0))
{
r++;
}
try
{
if ((r >= dbFiles.Length) || ((dbFiles[r] + "").Equals(files[q]) == false))
{
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + directories[i] + "/" + files[q]);
request.Method = WebRequestMethods.Ftp.DeleteFile;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
response.Close();
}
}
catch (Exception exception)
{ }
}
j++;
}
else
{
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + directories[i] + "/");
request.Method = WebRequestMethods.Ftp.ListDirectory;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
reader = new StreamReader(responseStream);
ArrayList files = new ArrayList();
while (!reader.EndOfStream)
{
files.Add(reader.ReadLine());
}
reader.Close();
response.Close();
for (int k = 0; k < files.Count; k++)
{
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + directories[i] + "/" + files[k]);
request.Method = WebRequestMethods.Ftp.DeleteFile;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
response.Close();
}
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + directories[i] + "/");
request.Method = WebRequestMethods.Ftp.RemoveDirectory;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
response.Close();
}
}
catch (Exception exception)
{
}
}
while (j < agents.Length)
{
try
{
request = (FtpWebRequest)WebRequest.Create("ftp://myurl.com/mainfolder/" + agents[j] + "/");
request.Method = WebRequestMethods.Ftp.MakeDirectory;
request.Credentials = new NetworkCredential("myusername", "mypassword");
response = (FtpWebResponse)request.GetResponse();
responseStream = response.GetResponseStream();
response.Close();
}
catch (Exception exception)
{ }
j++;
}
MessageBox.Show("DONE");
}
它用于从服务器中删除已弃用的目录和文件。我有一个主文件夹，其中所有子文件夹都是数字，所有子文件夹只包含文件（没有子文件夹的子文件夹）
服务器上的文件夹将存储在名为目录的ArrayList中。
存储在数据库中的目录ID将被加载到String []中，称为代理。
目录将以ascendent顺序排序，类似地，代理按照ascendent顺序排序（这两个都是此项目中的数字，因此它们按数字排序）
如果服务器上存在目录，但数据库中不存在该目录，则会删除该目录（首先删除所有文件，然后删除该文件夹本身）
如果服务器上不存在目录，但存储目录列表中存在该目录，则该目录将在服务器上创建。
如果服务器和存储目录列表中也存在目录，则将删除不推荐使用的文件。服务器上相应目录中的文件称为文件，存储在数据库中的文件存储在名为dbFiles的String[]中。
此功能实质上创建了要创建的文件夹，删除了要删除的文件夹并删除了要删除的文件，并且它可以正常工作。但是，我注意到在某些情况下，当发生服务器错误时，索引会回落，我想知道原因是什么。
例如i = 500和（我不知道为什么）当i = 100的情况下，当一个命令捕获服务器错误并且我回落到100时。
我的问题是：为什么我的索引会在收到先前发生的错误后退回？
当我100岁时，j会回到状态吗？
如何防止此回退？
答案 0 :(得分：3)
你应该重构你的代码，以便ftp命令在函数中，而不是在任何地方复制/粘贴那些ftp命令，你有这样的流程：
String[] directories = ftpGetListing("ftp://myurl.com/mainfolder/");
String[] agents = Crawler.CrawlerDbUtils.getAllAgentIDs();
String[] combinedDirectories = getElementsInBothArray(directories, agents);
String[] serverOnlyDirectories = getElementsOnlyInFirstArray(directories, agents);
String[] agentOnlyDirectories = getElementsOnlyInFirstArray(agents, directories);
// step 1: delete all server only directories
ftpDeleteDirectories("ftp://myurl.com/mainfolder/", serverOnlyDirectories);
// step 2: create all agent only directories
ftpCreateDirectories("ftp://myurl.com/mainfolder/", agentOnlyDirectories);
// step 3: depricate all files
foreach(String dir in combinedDirectories)
{
String ftpDir = "ftp://myurl.com/mainfolder/" + dir + "/";
String[] serverFiles = ftpGetListing(ftpDir);
String[] agentFiles = Crawler.CrawlerDbUtils.getAllPictures(dir);
String[] serverOnlyFiles = getElementsOnlyInFirstArray(serverFiles, agentFiles);
foreach(String file in serverOnlyFiles)
{
ftpDeleteFile(ftpDir + file);
}
}
然后，您只需为ftpGetListing，ftpDeleteDirectories，ftpCreateDirectories和ftpDeleteFile实现非常简单的功能。哦，是的和一些简单的数组操作函数，如：getElementsInBothArrays和getElementsOnlyInFitstArray。
答案 1 :(得分：1)
不是J正在被重置，而是它没有被增加。下面是一个模拟控制流程的控制台程序。
控制台的输出变化很大，具体取决于是否抛出了新的InvalidOperationException。这就在你的附近（！reader.EndOfStream）。
老实说，这种流程非常复杂。如果将这种方法分解成一口大小的碎片，你可能会得到很好的服务。
class Program
{
static void Main(string[] args)
{
int agentCount = 1000;
int directoriesCount =100;
int fileCount = 100;
int dbFilesCount = 100;
int j = 0;
for (int i = 0; i < directoriesCount; i++)
{
Console.WriteLine("I : {0}", i);
try
{
while ((j < agentCount))
{
try
{
}
catch (Exception exception)
{ }
j++;
Console.WriteLine("J : {0}", j);
}
if (true)
{
//throw new InvalidOperationException("Some error"); UnComment and see
while (false)
{
}
int r = 0;
for (int q = 0; q < fileCount; q++)
{
while ((r < dbFilesCount) )
{
r++;
}
try
{
if ((r >= dbFilesCount))
{
}
}
catch (Exception exception)
{ }
}
j++;
Console.WriteLine("J : {0}", j);
}
else
{
while (false)
{
}
for (int k = 0; k < fileCount; k++)
{
}
}
}
catch (Exception exception)
{
}
}
while (j < agentCount)
{
try
{
}
catch (Exception exception)
{ }
j++;
Console.WriteLine("J : {0}", j);
}
Console.WriteLine("Done");
Console.ReadLine();
}
}
答案 2 :(得分：1)
我发现了什么是解决方案。
首先，必须设置此项以避免此问题：
request.KeepAlive = false;
其次，在捕获中必须包括：
response.Close();
responseStream.Close();
当我们打开一个responseStream时，只有
response.Close();
当没有打开responseStream时。
我不确定这个问题的原因，但我认为C＃正在为我的源代码做一个分叉。