The class BasicFileAttributes, for examining the properties of a file in the file system, has the method isRegularFile(). Unfortunately, the Javadoc description is rather lacking:
Tells whether the file is a regular file with opaque content.
What does this mean? What exactly is a regular file with opaque content? I can tell from the other methods in the class that it's not a directory or symbolic link, so I'm inclined to think that it's everything else. However, there apparently is some type of "irregular file" because a method exists called isOther(), which returns true if it's not a directory, symbolic link, or "regular file".
So what exactly is an regular file in Java?