//删除文件夹
	private void deleteDirectory(File folder) {
		if (folder.exists()) {
			File[] files = folder.listFiles();
			if (files == null) {
				return;
			}
			for (int i = 0; i < files.length; i++) {
				if (files[i].isDirectory()) {
					deleteDirectory(files[i]);
				} else {
					files[i].delete();
				}
			}
		}
		folder.delete();
	}