How do I serialize an object and save it to a file in Android?

Saving (w/o exception handling code):

FileOutputStream fos = context.openFileOutput(fileName, Context.MODE_PRIVATE);ObjectOutputStream os = new ObjectOutputStream(fos);os.writeObject(this);os.close();fos.close();

Loading (w/o exception handling code):

FileInputStream fis = context.openFileInput(fileName);ObjectInputStream is = new ObjectInputStream(fis);SimpleClass simpleClass = (SimpleClass) is.readObject();is.close();fis.close();

I've tried this 2 options (read/write), with plain objects, array of objects (150 objects), Map:

Option1:

FileOutputStream fos = context.openFileOutput(fileName, Context.MODE_PRIVATE);ObjectOutputStream os = new ObjectOutputStream(fos);os.writeObject(this);os.close();

Option2:

SharedPreferences mPrefs=app.getSharedPreferences(app.getApplicationInfo().name, Context.MODE_PRIVATE);SharedPreferences.Editor ed=mPrefs.edit();Gson gson = new Gson(); ed.putString("myObjectKey", gson.toJson(objectToSave));ed.commit();

Option 2 is twice quicker than option 1

The option 2 inconvenience is that you have to make specific code for read:

Gson gson = new Gson();JsonParser parser=new JsonParser();//object arr exampleJsonArray arr=parser.parse(mPrefs.getString("myArrKey", null)).getAsJsonArray();events=new Event[arr.size()];int i=0;for (JsonElement jsonElement : arr)    events[i++]=gson.fromJson(jsonElement, Event.class);//Object examplepagination=gson.fromJson(parser.parse(jsonPagination).getAsJsonObject(), Pagination.class);

I just made a class to handle this with Generics, so it can be used with all the object types that are serializable:

public class SerializableManager {    /**     * Saves a serializable object.     *     * @param context The application context.     * @param objectToSave The object to save.     * @param fileName The name of the file.     * @param <T> The type of the object.     */    public static <T extends Serializable> void saveSerializable(Context context, T objectToSave, String fileName) {        try {            FileOutputStream fileOutputStream = context.openFileOutput(fileName, Context.MODE_PRIVATE);            ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);            objectOutputStream.writeObject(objectToSave);            objectOutputStream.close();            fileOutputStream.close();        } catch (IOException e) {            e.printStackTrace();        }    }    /**     * Loads a serializable object.     *     * @param context The application context.     * @param fileName The filename.     * @param <T> The object type.     *     * @return the serializable object.     */    public static<T extends Serializable> T readSerializable(Context context, String fileName) {        T objectToReturn = null;        try {            FileInputStream fileInputStream = context.openFileInput(fileName);            ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);            objectToReturn = (T) objectInputStream.readObject();            objectInputStream.close();            fileInputStream.close();        } catch (IOException | ClassNotFoundException e) {            e.printStackTrace();        }        return objectToReturn;    }    /**     * Removes a specified file.     *     * @param context The application context.     * @param filename The name of the file.     */    public static void removeSerializable(Context context, String filename) {        context.deleteFile(filename);    }}