在业务开发中经常会遇到需要保存对象到文件的需求，如下函数是通过FileChannel来保存ArrayList<HashMap<String, String>>对象到磁盘，并从磁盘读取还原ArrayList<HashMap<String, String>>对象的方法：

	/**
	 * 保存加密后的数据到本地磁盘
	 * @param context 上下文
	 * @param data 需要保存的ArrayList<HashMap<String, String>>
	 * @param path 保存路径
	 * @return boolean
	 */
	public static synchronized boolean saveObject(Context context, ArrayList<HashMap<String, String>> data, String path) {
		try {
			byte[] encrypted = encryptData(DeviceHelper.getInstance(context).getModel(), data);
			FileOutputStream fos = new FileOutputStream(path);
			FileChannel channel = fos.getChannel();
			channel.write(ByteBuffer.wrap(encrypted));
			channel.force(true);//强制刷新
			channel.close();
			return true;
		} catch (Throwable t) {
		}
		return false;
	}

	/**
	 * 从本地磁盘获取已保存的数据
	 * @param context 上下文
	 * @param path 路径
	 * @return ArrayList<HashMap<String, String>>
	 */
	public static synchronized ArrayList<HashMap<String, String>> loadObject(Context context, String path) {
		try {
			FileInputStream fis = new FileInputStream(path);
			FileChannel channel = fis.getChannel();
			ByteBuffer byteBuffer = ByteBuffer.allocate((int) channel.size());
			while ((channel.read(byteBuffer)) > 0) {
				// do nothing
			}
			byte[] dataByte = byteBuffer.array();
			channel.close();
			return decryptData(DeviceHelper.getInstance(context).getModel(), dataByte);
		} catch (Throwable t) {
		}
		return new ArrayList<HashMap<String, String>>();
	}

	private static byte[] encryptData(String key, ArrayList<HashMap<String, String>> data) {
		Hashon hashon = new Hashon();
		String json = hashon.fromObject(data);
		try {
			return Data.AES128Encode(key, json);
		} catch (Throwable t) {
		}
		return json.getBytes();
	}

	private static ArrayList<HashMap<String, String>> decryptData(String key, byte[] dataByte) {
		try {
			String decrypted = Data.AES128Decode(key, dataByte);
			ArrayList<HashMap<String, String>> list = getArrayListByString(decrypted);
			return list;
		} catch (Throwable t) {
		}
		return new ArrayList<HashMap<String, String>>();
	}

	private static ArrayList<HashMap<String, String>> getArrayListByString(String json) {
		try {
			ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
			if (TextUtils.isEmpty(json)) {
				return list;
			}
			JSONArray jsonArray = new JSONArray(json);
			Hashon hashon = new Hashon();
			for (int i = 0; i < jsonArray.length(); i++) {
				list.add(hashon.<String>fromJson(jsonArray.getJSONObject(i).toString()));
			}
			return list;
		} catch (Throwable t) {
		}
		return new ArrayList<HashMap<String, String>>();
	}