I have tried to create various folders which name came after class packages and found that some can be created but not others. I've found that folders ending with possible extension e.g. ".app",".crt" throw an error when created. I've checked and .app and .crt are by default forbidden FILE extensions, so why does this rule affect folder creation? Also why is this not mentioned in the folder name rules? Who knows I would like to know if there is a workaround that will allow me to create desired folders.
Go into central admin and edit those extentions not to be forbidden ;) , there is a reason why they are as they could be reserved for other things or could be well known file formats for embedding virus / trojan ect...
goto Central Admin,
click on Security,
under General click on Define blocked file types
remove the file types you want to use! but doing this will allow users to upload those .filetype names into sharepoint site opening your site to vunrability ;) just be carefull!! known types should stay blocked like .exe ect
other solution is to programmatically do it! you can unblock the file type and the reblock it during the folder creation, but doing this tho will still leave a problem of the folder being blocked when viwing the folder location as its a blocked file type lol, so more config and messing around would make it horrid! rule of thum dont use blocked file types and change the naming convention to best practices!
ok so you have com.examples.app but cant you trade it for com-examples-app in sharepoint? so any . become - that way you dont need to unblock the file types and keep the naming convention (almost)
just to make it clear that folder names take the same conditions as file naming convention and physical file/folder naming convention:
also like to make it clear that having a blocked .extention in a folder is also not allowed!
exe is a blocked file type, rtd isnot and would be excepted, doc is the actual file and is accepted.
to get around this do:
that will indicate to sharepoint folder-exe-rtd is a folder and not a file and myfile.doc is the file within that folder! so in your case do the above or just dont use any blocked file types that it might think it is ;)
for a list of blocked file types by default in sharepoint is:
.app is one of them!