问题序列化和反序列化ArrayList

private void serializeQuotes(){        FileOutputStream fos;        try { fos = openFileOutput(Constants.FILENAME, Context.MODE_PRIVATE); ObjectOutputStream oos = new ObjectOutputStream(fos); oos.writeObject(quotes);  oos.close();        } catch (FileNotFoundException e) { e.printStackTrace();        }catch(IOException e){ e.printStackTrace();        }    }    @SuppressWarnings("unchecked")    private void deserializeQuotes(){        try{ FileInputStream fis = openFileInput(Constants.FILENAME); ObjectInputStream ois = new ObjectInputStream(fis); quotes = (ArrayList<Quote>) ois.readObject();        } catch (FileNotFoundException e) { e.printStackTrace();        }catch(IOException e){ e.printStackTrace();        }catch(ClassNotFoundException e){ e.printStackTrace();        }    }