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From sebb <seb...@gmail.com>
Subject Re: NPE in getRemoteAdress
Date Tue, 30 Aug 2016 14:23:55 GMT
On 29 August 2016 at 18:28, Oliver Zemann <oliver.zemann@gmail.com> wrote:
> My download method looks like this:
>
> private void downloadDirectory(FTPClient client, String sourceDir, String
> destDir,
>                                    ScheduledExecutorService
> scheduledExecutorService) throws IOException {
>
>         final FTPFile[] ftpFiles = client.listFiles(sourceDir);
>         for (final FTPFile ftpFile : ftpFiles) {
>
>             //skip . and ..
>             if (ftpFile.isDirectory() && (ftpFile.getName().equals(".") ||
> ftpFile.getName().equals(".."))) {
>                 continue;
>             }
>
>             if (ftpFile.isDirectory()) {
>                 downloadDirectory(client, sourceDir + ftpFile.getName(),
> destDir + "/" + ftpFile.getName(), scheduledExecutorService);
>             } else {
> //                scheduledExecutorService.submit(new
> DownloadRunnable(destDir, ftpFile, sourceDir, client));
>                 FileOutputStream fos = new
> FileOutputStream(ftpFile.getName());
>                 client.retrieveFile(sourceDir + ftpFile.getName(), fos );
>                 fos.flush();
>                 fos.close();
>             }
>         }
>     }
>
> When i run it like this, it works and it downloads the files. But when i use
> the scheduledExecuterService, it fails.
> So i replaced the 2 lines with my download method (where it uses the
> inputstream) to see what happens:
>
>  } else {
> //                scheduledExecutorService.submit(new
> DownloadRunnable(destDir, ftpFile, sourceDir, client));
>                 new File(destDir).mkdirs();
>                 final File outFile = new File(destDir, ftpFile.getName());
>                 final FileOutputStream fos = new FileOutputStream(outFile);
>                 final InputStream inputStream =
> client.retrieveFileStream(sourceDir + ftpFile.getName());
>
>                 byte[] buffer = new byte[8096];
>                 int len = -1;
>                 try {
>                     len = inputStream.read(buffer, 0, buffer.length);
>                 } catch (Exception ex) {
>                     ex.printStackTrace();
>                 }
>                 while (len != -1) {
>                     fos.write(buffer, 0, len);
>                     len = inputStream.read(buffer);
>                     if (Thread.interrupted()) {
>                         throw new InterruptedException();
>                     }
>                 }
>                 client.completePendingCommand();
> //                informListenersWeFinishedOneFile(sourceDir +
> ftpFile.getName(), bytesWritten);
>                 fos.flush();
>                 fos.close();
>             }
>         }
>
> That works too?!
>
> I will go deeper into that at weekend and check whats going on, but at the
> moment i really dont understand it. Maybe some kind of concurrency problem
> with FTPClient?

That seems the most likely.

FTPClient is not guaranteed to be thread-safe.
I'm not sure that the java.io classes such as InputStream are thread
safe either.

>
> Am 29.08.2016 um 01:40 schrieb Martin Gainty:
>>
>> possible timeout waiting for FTP to reply
>> examples.ftp.FTPClientExample says to increase FTP reply timeout with -w
>> parameter
>>   if (args[base].equals("-w")) {
>> controlKeepAliveReplyTimeout = Integer.parseInt(args[++base]);            }
>> or with FTPClient:ftpClient.setControlKeepAliveReplyTimeout(2000); //2 sec
>> reply timeout
>> ?
>> Martin
>> ______________________________________________
>>
>>
>>
>>> Date: Sun, 28 Aug 2016 20:06:46 +0200
>>> From: ecki@zusammenkunft.net
>>> To: user@commons.apache.org
>>> CC: oliver.zemann@gmail.com
>>> Subject: Re: NPE in getRemoteAdress
>>>
>>> Hello,
>>>
>>> I am not sure about your NPE, but this code here ignores the result of
>>> the read call. It cannot deal with short reads:
>>>
>>>   Am Sun, 28 Aug 2016
>>> 15:50:36 +0200 schrieb Oliver Zemann <oliver.zemann@gmail.com>:
>>>>
>>>> byte b[] =new byte[4096];
>>>> while (inputStream.read(b) != -1) {
>>>>    fos.write(b);
>>>>    bytesWritten += b.length;
>>>
>>>
>>> Gruss
>>> Bernd
>>>
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>>>
>>
>
>
>
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