public class Main {

    private static ArrayList<File> getAllImages(String basePath) {
        ArrayList<File> filesList = new ArrayList<File>();
        getAllFilesHelper(basePath, filesList);
        return filesList;
    }


    private static void getAllFilesHelper(String directoryName, List<File> files) {
        File directory = new File(directoryName);
        // Get all the files from a directory.
        File[] fList = directory.listFiles();
        if (fList == null)
            return;
        for (File file : fList) {
            if (file.isFile()) {
                files.add(file);
            } else if (file.isDirectory()) {
                getAllFilesHelper(file.getAbsolutePath(), files);
            }
        }
    }

    public static void main(String[] args) {
    System.out.println("Hello again!");
    // will print paths of all files in folder and subfolders
    System.out.println(getAllImages("C:\\temp"));
    }
}