java isDirectory显示错误的结果

Question

I have the following code that checks if a file is a directory, and if not, creates it.

        File folder = new File(destFolder);
        if (!folder.isDirectory()) {
            if (!folder.mkdir()) {
                System.out.println("Could not create " + folder.getAbsolutePath());
                return null;
            }
        }

The code outputs "Could not create " always. I checked and confirmed that the folder with that name already exists. What could be the reason?

If I remove the destFolder, still it is showing the same error. Checked the permissions, I have read, write and execute permissions to the folder. (Weird thing is, it was working till last Friday!)

My machine runs Windows 7, and I am running the code from Netbeans. Java Platform is - JDK 1.7

Answer 1

You only get to the mkdir() call if the file is not a directory, in other words if it is a file. You're trying to run mkdir() against a file. You should be checking to see if it exists, not if it's a directory.