将文件移动到文件名中带有路径分隔符“ /”的文件

Question

I try to move a file from one directory to another. I do this with

File fileToMove = new File("/Users/kai-dj/separator_problem/from/file_to_move.file");
File destDir = new File("/Users/kai-dj/separator_problem/to");
if (fileToMove.exists() && destDir.isDirectory()) {
  fileToMove.renameTo(new File(destDir.getAbsolutePath()+File.pathSeparator+fileToMove.getName()));
}

I'd expect to find file_to_move.file in folder /Users/kai-dj/separator_problem/to after execution, but I get a file named to/file_to_move.file placed in the parent folder /Users/kai-dj/separator_problem . At least that's what Finder shows.

As I thought: "File names mustn't contain path separator characters, this can't be true.", I also checked what ls would output in terminal:

mac-book:separator_problem kai-dj$ ls
from        to:file_to_move.file
to          

OK – seems no / in file name. Very strange nontheless. Why does Finder show it as file name containing / ? Why does Java rename the file to <dirname>:<filename> – especially even when I used File.pathSeparator , not / and certainly not : ?

I also tried with Files.move – same result.

EDIT: Solved, but I'd still love to know, why Finder shows : as / ^^

Answer 1

As mentioned in the comment above, the correct member to use is called File.separator .

Also, you can avoid using File.separator in general, and use Paths instead:

System.out.println(Paths.get("/Users/kai-dj/separator_problem/to", fileToMove.getName()).toAbsolutePath());