Saving Files in CodenameOne

Question

I'm trying to save some screen dumps to internal storage for debugging purposes, but I can't seem to get access to them. When I call FileSystemStorage.getInstance().getAppHomePath(), I get a path that looks something like this:

/data/data/com.mycompany.myapp/files/

But I can't see this folder in the Android File Transfer tool, so I can't drag the files to my Mac. I also tried attaching them to an email using the Message class, but for some reason the attachments never showed up. I notice that a lot of applications store data in folders like this:

/Android/data/com.doubletwist.androidplayer/

If I try to create a folder like this, I run into two problems. First, it's not platform independent. (This doesn't matter much because I'm just doing this for debugging.) Second, it doesn't work. I get an error telling me I need to use the directory returned by FileSystemStorage.getInstance().getAppHomePath()

Is there any way I can save files to a folder that I can actually retrieve them from? It would be more helpful if I had a platform-independent way, but any way that works is fine for now.

Answer 1

File system is a very "unportable" notion. By default app home is a private folder which some mobile OS's including Android 4+ keep private and inaccessible.

Android has a concept of "sdcard" which used to be a physical storage where you could write anything in any directory without a problem. This is no longer applicable for later versions of Android but you can read from the sdcard directory and detect it.

FileSystemStorage has an API to get roots and their types, if you have an sdcard type you can read from there. You can use the FileTree to see the file hierarchy as exposed to your application which can be useful for debugging.