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Failed on retrieving video file from FTP site in Java.

Posted on 2007-12-05
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Last Modified: 2013-12-29
I am using the Apache common api to retrieve a video file from FTP site. Somehow, the file is empty in my linux system. I tried to retrieve xml files which is fine.

I attached my code, please help me out!!
FTPClient ftp = new FTPClient();
      ftp.connect( server );
      ftp.login( username, password );
      System.out.println("Connected to " + 
           server + ".");
      System.out.print(ftp.getReplyString());
 
      // List the files in the directory
      ftp.changeWorkingDirectory( folder );
      FTPFile[] files = ftp.listFiles();
      System.out.println( "Number of files in dir: " + files.length );
      DateFormat df = DateFormat.getDateInstance( DateFormat.SHORT );
      for( int i=0; i<files.length; i++ )
      {
        Date fileDate = files[ i ].getTimestamp().getTime();
        if( fileDate.compareTo( start.getTime() ) >= 0 &&
          fileDate.compareTo( end.getTime() ) <= 0 )
        {
          // Download a file from the FTP Server
          System.out.print( df.format( files[ i ].getTimestamp().getTime() ) );
          System.out.println( "\t" + files[ i ].getName() );
          File file = new File( destinationFolder + 
               File.separator + files[ i ].getName() );
          FileOutputStream fos = new FileOutputStream( file ); 
          ftp.retrieveFile( files[ i ].getName(), fos );
          fos.close();
          file.setLastModified( fileDate.getTime() );
        }
      }
 
      // Logout from the FTP Server and disconnect
      ftp.logout();
      ftp.disconnect();

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Question by:a122178
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10 Comments
 
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Expert Comment

by:CEHJ
ID: 20416559
Check the return value of retrieveFile
0
 
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Expert Comment

by:CEHJ
ID: 20416565
And make sure you're not ignoring exceptions
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Author Comment

by:a122178
ID: 20416720
The return value is fine. And I do not see any exception.

Now, I see part of the content has been download. The target file is 17MB.. but the retrieve stop at 5.8MB without any exception.

Thanks,
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Author Comment

by:a122178
ID: 20416730
Do you think I have to set the timeout or sth.. like that.

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Expert Comment

by:CEHJ
ID: 20418017
>>The target file is 17MB.. but the retrieve stop at 5.8MB without any exception.

Test it thoroughly without Java to eliminate general network problems
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Accepted Solution

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ysnky earned 250 total points
ID: 20418112
you have to set binary transfer mode to download binary files

add this
ftp.setFileType(FTP.BINARY_FILE_TYPE);
after "System.out.print(ftp.getReplyString());" line.
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Author Comment

by:a122178
ID: 20421645
Not related to the binary and networking issue too.

I found out the problem. If the file size is too large, the code below should be used instead. The reason is because the restrieveFile method has a thread inside which will stop after a certain time. (maybe)


ftp.retrieveFile( files[ i ].getName(), fos );
 
// should use this 
 
InputStream is = ftp.retrieveFileStream( files[ i ].getName());

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Assisted Solution

by:CEHJ
CEHJ earned 250 total points
ID: 20421721
>>The reason is because the restrieveFile method has a thread inside which will stop after a certain time. (maybe)

Sounds very mysterious ;-)
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LVL 86

Expert Comment

by:CEHJ
ID: 20421729
I must say i've noticed some pretty strange behaviour from this API too. I ditched it in favour of another
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Expert Comment

by:ysnky
ID: 20425791
i have had problem with binary files when i dont set ftp filetype to binary.
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