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文件系统监视程序和ftp

filesystemwatcher ftp c#

Brandon Grossutti · 技术社区 · 17 年前

我通过文件系统监视程序监视掉在FTP上的文件,然后移到另一个目录。现在,我从文件系统监视程序的create事件中触发复制,但很明显,在ftp的情况下,create只是一个存根文件,当文件上载到完成时,数据会进入并填充文件。任何人都有一个很好的解决办法,还是我必须做我认为必须做的事?

1 wait till last access time is about n ms in past before I copy
2 throw a control file in there to state that that file is done being copied, then delete control file
3 pound the crap out of it

6 回复 | 直到 17 年前

Brandon Grossutti 17 年前

这是一个非常幼稚的实现,但它符合我的目的,我在网上看到了足够多的人用这个问题做出了贡献。实现是针对我的需求的,考虑到我的问题的性质,我几乎完全不关心已更改的事件,但是如果人们需要做一些不同的事情,他们可以将自己的代码放在其中,这实际上是导致大多数问题的创建。我还没有完全测试过这个,但一开始写得不错

using System;
using System.Collections.Generic;
using System.IO;
using System.Timers;

namespace FolderSyncing
{
    public class FTPFileSystemWatcher 
    {
        private readonly string _path;
        public event FileSystemEventHandler FTPFileCreated;
        public event FileSystemEventHandler FTPFileDeleted;
        public event FileSystemEventHandler FTPFileChanged;

        private Dictionary<string, LastWriteTime> _createdFilesToCheck;
        private readonly object _lockObject = new object();
        private const int _milliSecondsSinceLastWrite = 5000;
        private const int _createdCheckTimerInterval = 2000;

        private readonly FileSystemWatcher _baseWatcher;

        public FTPFileSystemWatcher(string path, string Filter)
        {
            _path = path;
            _baseWatcher = new FileSystemWatcher(path,Filter);
            SetUpEventHandling();
        }

        public FTPFileSystemWatcher(string path)
        {
            _path = path;
            _baseWatcher = new FileSystemWatcher(path);
            SetUpEventHandling();
        }

        private void SetUpEventHandling()
        {
            _createdFilesToCheck = new Dictionary<string, LastWriteTime>();
            Timer copyTimer = new Timer(_createdCheckTimerInterval);
            copyTimer.Elapsed += copyTimer_Elapsed;
            copyTimer.Enabled = true;
            copyTimer.Start();
            _baseWatcher.EnableRaisingEvents = true;
            _baseWatcher.Created += _baseWatcher_Created;
            _baseWatcher.Deleted += _baseWatcher_Deleted;
            _baseWatcher.Changed += _baseWatcher_Changed;
        }

        void copyTimer_Elapsed(object sender, ElapsedEventArgs e)
        {
            lock (_lockObject)
            {
                Console.WriteLine("Checking : " + DateTime.Now);
                DateTime dateToCheck = DateTime.Now;
                List<string> toRemove = new List<string>();
                foreach (KeyValuePair<string, LastWriteTime> fileToCopy in _createdFilesToCheck)
                {
                    FileInfo fileToCheck = new FileInfo(_path + fileToCopy.Key);
                    TimeSpan difference = fileToCheck.LastWriteTime - fileToCopy.Value.Date;
                    fileToCopy.Value.Update(fileToCopy.Value.Date.AddMilliseconds(difference.TotalMilliseconds));
                    if (fileToCopy.Value.Date.AddMilliseconds(_milliSecondsSinceLastWrite) < dateToCheck)
                    {
                        FileSystemEventArgs args = new FileSystemEventArgs(WatcherChangeTypes.Created, _path, fileToCopy.Key);
                        toRemove.Add(fileToCopy.Key);
                        InvokeFTPFileCreated(args);
                    }
                }
                foreach (string removal in toRemove)
                {
                    _createdFilesToCheck.Remove(removal);
                }
            }
        }



        void _baseWatcher_Changed(object sender, FileSystemEventArgs e)
        {
            InvokeFTPFileChanged(e);
        }

        void _baseWatcher_Deleted(object sender, FileSystemEventArgs e)
        {
            InvokeFTPFileDeleted(e);
        }

        void _baseWatcher_Created(object sender, FileSystemEventArgs e)
        {
            if (!_createdFilesToCheck.ContainsKey(e.Name))
            {
                FileInfo fileToCopy = new FileInfo(e.FullPath);
                _createdFilesToCheck.Add(e.Name,new LastWriteTime(fileToCopy.LastWriteTime));
            }
        }

        private void InvokeFTPFileChanged(FileSystemEventArgs e)
        {
            FileSystemEventHandler Handler = FTPFileChanged;
            if (Handler != null)
            {
                Handler(this, e);
            }
        }

        private void InvokeFTPFileDeleted(FileSystemEventArgs e)
        {
            FileSystemEventHandler Handler = FTPFileDeleted;
            if (Handler != null)
            {
                Handler(this, e);
            }
        }

        private void InvokeFTPFileCreated(FileSystemEventArgs e)
        {
            FileSystemEventHandler Handler = FTPFileCreated;
            if (Handler != null)
            {
                Handler(this, e);
            }
        }
    }

    public class LastWriteTime
    {
        private DateTime _date;

        public DateTime Date
        {
            get { return _date; }
        }

        public LastWriteTime(DateTime date)
        {
            _date = date;
        }

        public void Update(DateTime dateTime)
        {
            _date = dateTime;
        }



    }
}

RichardOD 17 年前

等到你能完全打开文件-我不会说这是一个很好的解决方案,但可能是在这种情况下最安全的策略。

jp2code 9 年前

这是一个要保持同步的实现

using System;
using System.Configuration;
using System.IO;
using System.Threading;

namespace FolderSyncing
{
    public class FolderSync
    {
        private readonly string masterDirectoryPath;
        private readonly string slaveDirectoryPath;

        public FolderSync()
        {
            masterDirectoryPath = ConfigurationManager.AppSettings.Get("MasterDirectory");
            slaveDirectoryPath = ConfigurationManager.AppSettings.Get("SlaveDirectory");

            if (Directory.Exists(masterDirectoryPath) && Directory.Exists(slaveDirectoryPath))
            {
                FTPFileSystemWatcher watcher = new FTPFileSystemWatcher(masterDirectoryPath);
                watcher.FTPFileChanged += watcher_FTPFileChanged;
                watcher.FTPFileCreated += watcher_FTPFileCreated;
                watcher.FTPFileDeleted += watcher_FTPFileDeleted;
            }
            else
            {
                Console.WriteLine("Directories were not located check config paths");
            }

        }

        void watcher_FTPFileDeleted(object sender, FileSystemEventArgs e)
        {
            DeleteFile(slaveDirectoryPath + e.Name, 5, 1);
        }

        void watcher_FTPFileCreated(object sender, FileSystemEventArgs e)
        {
            CopyFile(e.Name,5,1);
        }

        void watcher_FTPFileChanged(object sender, FileSystemEventArgs e)
        {

        }

        private void DeleteFile(string fullPath, int attempts, int attemptNo)
        {
            if (File.Exists(fullPath))
            {
                try
                {
                    File.Delete(fullPath);
                    Console.WriteLine("Deleted " + fullPath);
                }
                catch (Exception)
                {
                    if (attempts > attemptNo)
                    {
                        Console.WriteLine("Failed deleting  " + fullPath + "trying again "+ attemptNo.ToString()+ " of "+attempts);
                        Thread.Sleep(500);
                        DeleteFile(fullPath, attempts, attemptNo + 1);
                    }
                    else
                    {
                        Console.WriteLine("Critically Failed deleting  " + fullPath);
                    }
                }
            }
        }

        private void CopyFile(string fileName,int attempts, int attemptNo)
        {
            string masterFile = masterDirectoryPath + fileName;
            string slaveFile = slaveDirectoryPath + fileName;
            if (File.Exists(masterFile))
            {
                try
                {
                    File.Copy(masterFile,slaveFile);
                    Console.WriteLine("Copied  " + masterFile);
                }
                catch (Exception)
                {
                    if (attempts > attemptNo)
                    {
                        Console.WriteLine("Failed copying  " + masterFile + "trying again " + attemptNo.ToString() + " of " + attempts);
                        Thread.Sleep(500);
                        CopyFile(fileName, attempts, attemptNo + 1);
                    }
                    else
                    {
                        Console.WriteLine("Critically Failed copying  " + masterFile);
                    }
                }
            }
       }
    }
}

Mohit S 8 年前

当使用ftp从另一台服务器复制文件时,在完成文件复制之前,文件名将被重命名为额外的扩展名,如下面的路径示例中所示的.tmp。

C:\InterfaceServer\OilandGas\xmlfortest\teststbfile.xml.tmp

要克服这种情况,请遵循两个步骤

当运行文件监视程序方法时,filesystemEventArgs 参数包含附加了额外文件扩展名的文件名刚到达文件夹但尚未完成的文件名带复制操作。

您只需调用下面的方法来删除额外的扩展名并在代码中添加等待2秒钟,以便完整的文件创建并可用于进一步处理。

public static string VerifyIfStubFile(string filePath, string extension)
{             
    if (filePath.Length - (filePath.IndexOf(extension) + extension.Length) != 0)            
    {                
        /*LogMsg("Info : VerifyIfStubFile : Stub file found. Lets fix it!!"); */               
        return filePath = filePath.Substring(0, (filePath.IndexOf(extension) + extension.Length));            
    }            
    return filePath;        
}

Richard Ambrose 17 年前

让源文件在数据文件完成后直接上载一个存根文件,并让文件系统监视程序监视该存根文件。例如,如果数据文件名是mydata_01234,那么存根woulb就是mydata_01234_存根。然后,filesystemwatcher应该有一个“*\u stub”的掩码。然后去掉“_stub”后缀,就可以知道数据文件名。而且存根文件在数据文件完成后才能上载,所以数据文件是免费的。

如果存根文件只有一个字节,那么在对数据文件执行任何操作之后,都应该能够删除它们,而不会产生任何问题。如果您的操作速度特别快,请在删除存根之前添加100 ms睡眠。

WillyNillyMcPeep 12 年前

4年后……

存根文件是一个好主意,但是,一个更健壮的方法可能是让您的源文件先创建一个存根文件,上传您的“真实”文件,然后删除存根。