@Override
    public File createTempDirectory(String prefix) throws IOException {
        // Identify and create our temp dir, if needed
        createPOIFilesDirectory();

        // Generate a unique new filename
        File newDirectory = Files.createTempDirectory(dir.toPath(), prefix).toFile();

        //this method appears to be only used in tests, so it is probably ok to use deleteOnExit
        newDirectory.deleteOnExit();

        // All done
        return newDirectory;
    }
Creates the strategy allowing to set the

@param dir The directory where the temporary files will be created (<code>null</code> to use the default
           directory).
@see Files#createTempFile(Path, String, String, FileAttribute[])
fastexcel-core/src/main/java/cn/idev/excel/util/EasyExcelTempFileCreationStrategy.java