How to correctly compose the path to the file?

Question

Java

There is such a project structure:


Task:
- in FileAppender you need to specify the path to the file to which the logs will be written.

What I did:
Registered a path like this:

log/$${date:dd:MM:yyyy}/log-$${date:dd:MM:yyyy-HH:mm}.txt

But IntellijIDEA throws an exception:

ERROR FileManager (log/21:04:2021/log-21:04:2021_15:58.txt) java.io.IOException: The filename, directory name, or volume label syntax is incorrect

The official Log4J 2 documentation says that

fileName String The name of the file to write to. If the file, or any of its parent directories, do not exist, they will be created.

which means if the file does not exist in the given path, it will be created. By what rules then the way is set?

Question:
What is wrong in my path to the file where the logs will be written?

Answer 1

java.io.IOException: The filename, directory name, or volume label syntax is incorrect

file name, directory name, or volume name is incorrect.

The official Log4J 2 documentation says that
fileName String The name of the file to write to. If the file, or any of its parent directories, do not exist, they will be created.
which means if the file does not exist in the given path, it will be created. By what rules then the way is set?

Great, but there are still limitations on the names of the OS itself and / or the file system in it.
In Windows, this is \/:*?<>"|
There are also restrictions in the words themselves and you will find them at the link above.
In general, this is not a problem of java itself, and not a problem at all, these are limitations of the FS and OS.

Answer 2

I guess you need to write ./log/...

Answer 3

If in one package, then import is not needed, and if not in one, then through import package.directory.file or * to import everything, and if in another place, then the full path like DISK:\general_package\package\directory\file to import