Android - Store some settings in local config file

Question

I have an android app that at oncreate(), load a json setting file from a server, json file that have google analytics id, admob code, etc. Then app run.

Here is my current function how looks like

private void makeJsonObjectRequest() {
    JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET, url, null,
            new Response.Listener<JSONObject>() {
                @Override
                public void onResponse(JSONObject response) {
                    try {
                        JSONObject settings = response.getJSONObject("settings");
                        analyticid = settings.getString("google_anaytics");
                        admonbannerid = settings.getString("admob_banner");
                        admobinterstitialid = settings.getString("admob_interstitial");
                    } catch (JSONException e) {
                        e.printStackTrace();
                        Toast.makeText(getApplicationContext(), "Error: " + e.getMessage(), Toast.LENGTH_LONG).show();
                    }
                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    VolleyLog.d(TAG, "Error: " + error.getMessage());
                    Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();
                }
            });
    // Adding request to request queue
    addToRequestQueue(jsonObjReq);
}

But to optimize that, I want to create a local setting file in user device, when I store these settings, and instead of calling json each time, I check first this file, to get settings, if empty, then I generate new file.

Any one know a solution for that or it's possible?

Much appreciate and thank you very much in advance

Answer 1

You could use SharedPreferences to store the settings in the device.

• http://developer.android.com/guide/topics/data/data-storage.html#pref
• Example: http://www.androidhive.info/2012/08/android-session-management-using-shared-preferences/

From androidhive:

Initialize:

SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", 0); // 0 - for private mode
Editor editor = pref.edit();

Store data:

editor.putBoolean("key_name", true); // Storing boolean - true/false
editor.putString("key_name", "string value"); // Storing string
editor.putInt("key_name", "int value"); // Storing integer
editor.putFloat("key_name", "float value"); // Storing float
editor.putLong("key_name", "long value"); // Storing long

editor.commit(); // commit changes

Retrieve data:

// returns stored preference value
// If value is not present return second param value - In this case null
pref.getString("key_name", null); // getting String
pref.getInt("key_name", null); // getting Integer
pref.getFloat("key_name", null); // getting Float
pref.getLong("key_name", null); // getting Long
pref.getBoolean("key_name", null); // getting boolean

Clear/Delete one key/value:

editor.remove("name"); // will delete key name
editor.remove("email"); // will delete key email

editor.commit(); // commit changes

Clear/Delete all data:

editor.clear();
editor.commit(); // commit changes

You can also create a custom class to manage all the preferences and call it from everyplace you need. It would be something like:

public class SharedPreferencesManager {
    SharedPreferences pref;
    Editor editor;
    Context _context;
    int PRIVATE_MODE = 0;

    private static final String PREF_NAME = "my_preferences";

    //Preferences keys
    public static final String MY_KEY_ONE = "myKeyOne";

    // Constructor
    public SharedPreferencesManager(Context context){
        this._context = context;
        pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
        editor = pref.edit();
    }

    //STORE VALUE
    public void storeValue(String key, String value){ //value can be of any type you need
        //Save value
        editor.putString(key, value);

        // DONT FORGET to commit changes
        editor.commit();

    }

    //GET VALUE
    public String getStringValue(String key){
        return pref.getString(key, null);
    }

    //REMOVE ONE VALUE
    public void removeValue(String key){
        editor.remove(key);
        editor.commit();
    }

    //CLEAR DATA
    public void clearAllValues(){
        editor.clear();
        editor.commit();
    }

}

And use it like this:

//init
preferencesManager = new SharedPreferencesManager(getApplicationContext());

//Store Value
preferencesManager.storeValue(SharedPreferencesManager.MY_KEY_ONE, "superValue");

//Get value
String myKeyValue = preferencesManager.getStringValue(SharedPreferencesManager.MY_KEY_ONE);

//Check if value exists
if(myKeyValue == null){
     //loadFromJSON
}

//Clear all values
preferencesManager.clearAllValues();

Answer 2

why you don't store the settings as part of the local settings from the app you can use

SharedPreferences mPreferences = PreferenceManager
                .getDefaultSharedPreferences(mCtx);

SharedPreferences.Editor mEditor = mPreferences.edit();
mEditor.put("keyOfTheSetting",value);
mEditor.commit();

and to lookup if you have the settings

mPreferences.get("keyOfTheSetting","");