Question

I need to rename:

newfolder -> oldfolder;

I need to be sure that in case of exception old folder will be saved.

So I think to do next:

 1. rename oldfolder -> tempfolder.
 2. rename newfolder -> oldfolder.
 3. If previous ok - delete oldfolder.

But I have dubious – may be Apache FileUtils do the same. Or operation of renaming is safe.
What is correct?
Thanks.

Answer 1

If you try to rename a folder to an existing name it will fail. So if you want to replace a folder you should go with the alternative approach you already mentioned.

The logic would be

1. folder to folder.bak
2. folder.new to folder
3. if successful, delete folder.bak
4. elsewise folder.bak to folder and raise error