[dereks10]

I thought i would share my method of successfully avoiding duplicates. After posting here for scripts to compare files and trying third party apps i came up pretty short. Still suffered from duplicates until i found out about....Symbolic Links!
Think of them as 0 byte super-shortcuts. Just put your links of your downloaded files in one directory. Point J-downloader to download to that directory and you wont have to worry about duplicates anymore. Best part is that it takes up Zero space. Its easy to use. Just download "Link Shell Extension"
or the choclatey package "Link Shell Extension"

After you install. Right click the file or files.
Click "Pick Link Source"
Navigate to your download folder that JDownloader points to.
Click drop link as Symbolic Links.
( Optional i recomend hiding your symbolic links so things dont get confusing )

Now jdownloader will treat the 0Byte shortcuts as the actual files and skip over it.

I have about 12000 videos and ever since i started doing this method ive cut my dupes down to practically zero. As long as its the exact same file name then your good to go.

[Jiaz]

That's a nice but dirty workaround You simply symlink/shortcut every file into your download folder and thus create sort of *do not download again* list in your download folder.