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Thread: Scanning large FTP directories with apache.commons.net.ftp

  1. #1
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    Default Scanning large FTP directories with apache.commons.net.ftp

    Hi,

    I'm using apache.commons.net.ftp.FTPClient to scan an FTP directory which can contain thousands of files which have been written over several months.

    I'll only ever be interested in a recent subset of those files though (about a week's worth at most), but I'm having to loop through thousands of instances which is taking unacceptably long (over an hour). Is there any way that I can eliminate the older files on mass without having to painfully iterate through each one? Here's the code I'm currently using to do the date checks...

    client.cwd(directory);
    ftpFiles = client.listFiles(directory);

    for (FTPFile ftpFile : ftpFiles) {
    String name = ftpFile.getName();
    if (ftpFile.getType() == FTPFile.FILE_TYPE) {
    Date today = new Date();
    long dateDiffHours = (today.getTime() - ftpFile.getTimestamp().getTimeInMillis())/(1000 * 60 * 60);
    if (dateDiffHours>(argsQueryHours+2)){}else{
    //do something with the file because it's recent enough

    Any help would be really appreciated! Thanks,

    Daniel


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Scanning large FTP directories with apache.commons.net.ftp

    Is there any way that I can eliminate the older files on mass without having to painfully iterate through each one
    If you have a list of the filenames, how do you determine which file you want to process and which file you want to skip?
    What is in the ftpFiles object? Is there something local in the object that can be used to select a file?
    I assume that the problem is with the getTimeStamp() method requires a turnaround with the server.
    Is there a way to get a directory list from the server that will have the names and file's date all in one file obtained in one transaction?

    My simple FTP tool returns a dir list using the LISt command:

    drwxr-x---    2 a3180082   a3180082         4096 Feb  5 07:42 .
    drwx--x--x    3 a3180082   a3180082         4096 Dec  6 16:38 ..
    -rw-r--r--    1 a3180082   a3180082           91 Dec  6 16:04 .htaccess
    -rw-r--r--    1 a3180082   a3180082          363 Dec  7 13:38 AppletReader.html
    -rw-r--r--    1 a3180082   a3180082           41 Feb  5 07:42 AppletTestURL.txt
    -rw-r--r--    1 a3180082   a3180082        24016 Dec  6 16:39 ImagesInBlob.jar
    -rw-r--r--    1 a3180082   a3180082       324867 Dec  6 16:39 SmallBlob.dat
    -rw-r--r--    1 a3180082   a3180082          297 Dec  6 16:39 SmallBlob.html
    -rw-r--r--    1 a3180082   a3180082         8062 Dec  6 16:04 default.php
    -rw-r--r--    1 a3180082   a3180082         3676 Dec  7 13:38 sAppletReader.jar

    What is a "FTP directory"? Is that a directory on a FTP server?

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    Default Re: Scanning large FTP directories with apache.commons.net.ftp

    Hi Norm,

    Thanks for the response.

    ftpFiles is a list of FTPFile objects as specified here: FTPFile (Commons Net 3.0.1 API)

    Unfortunately I can't find anything that returns names and modified dates in one method though. So I'm having to iterate through each file in ftpFiles and examine the date of each.

    Can't find a LIST command that doesn't involve me having to loop through a list of files afterwards

    Any ideas?

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: Scanning large FTP directories with apache.commons.net.ftp

    The LIST command returned the file that I posted. Does the API have a way to use FTP commands directly?

    org.apache.commons.net.ftp
    Class FTPCommand

    Has the LIST command in its list of commands.

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