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Gary D. Gregory commented on NET-686: ------------------------------------- I mean create a test like {{org.apache.commons.net.ftp.FTPSClientTest}} that demonstrates your issue. > Most files aren't downloaded completely from an FTP server > ---------------------------------------------------------- > > Key: NET-686 > URL: https://issues.apache.org/jira/browse/NET-686 > Project: Commons Net > Issue Type: Bug > Components: FTP > Affects Versions: 3.6, 3.7.2 > Environment: Win 10 > Java 8 > Android Studio 3.6.1 (min SDK 24, target SDK 27) > Reporter: JRRR > Priority: Major > Attachments: 2a-original.png, 2b-corrupt.png, 2c-corrupt.png, > 5a-original.jpg, 5b-corrupt.jpg, 5c-corrupt.jpg, DownloadProblem.java > > > About a month ago I opened another > [issue|https://issues.apache.org/jira/browse/NET-684] that was closed because > it wasn't reproducible with macOS and a public FTP server. > Short summary: Downloading files from an FTP server results in these files > randomly missing bytes. It looks like the download always "completes" and > there are no error messages/exceptions but random bytes in random files are > simply skipped. Images (jpg & png) are usually affected more (up to 30, maybe > 40, bytes smaller than the original), and are then also visibly corrupt, than > text files (usually only 2-3 bytes smaller, rarely more). > I'm working on an Android app (Win 10, Java 8, Android Studio 3.6.1, min SDK > 24, target SDK 27), which I'm testing with FTP servers in the same network > (1x Win 10, 1x Linux, both accessed via IP - "10.1.1.xxx"). No matter what > method in the library I use (retrieveFile, retrieveFileStream, > sendCommand(FTPCmd.RETRIEVE, filename)), most of the time there's at least a > single file that's corrupted. > I also tested the same code with public servers and even though I didn't have > a lot of time because those servers regularely delete uploaded files, I never > experienced said problem with them. > I even wrote my own mini-library (just for login/logout and download) using > Java's default "Socket" but I still had the same problem on Android Studio's > simulator/a real device. BUT: When I used the same code to create a small > Windows/Swing/Java app, there were no more corrupted files. > It looks like this bug is only affecting a very specific combination of > OS,...: > Android (emulator/real device) + Java (8) + FTP server in the same network > (accessed via IP) -- This message was sent by Atlassian Jira (v8.3.4#803005)