Best way to store small amounts of data in android

Question

I have a very basic application that uses the Maps API to display a map, and after a long press it will put a marker down at that location. If you select a different location, it will delete the current marker and make a new one.

The app does what I want it to at the moment, but I can get the data to persist after the app it closed.

This is what I'm currently trying to do:

    @Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_maps);
      // Obtain the SupportMapFragment and get notified when the map is ready to be used.
      SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
      mapFragment.getMapAsync(this);

      BufferedReader reader;

      try {
          final InputStream file = getAssets().open("userLatLng");
          reader = new BufferedReader(new InputStreamReader(file));
          String line = reader.readLine();
          line = reader.readLine();
          System.out.print("Getting Data");
      } catch (IOException ioe) {
          ioe.printStackTrace();
      }
  }

That is used for reading the data after the application has started

            String filename = "userLatLng";
            FileOutputStream outputStream;

            try {
                outputStream = openFileOutput(filename, Context.MODE_PRIVATE);

                outputStream.write(Integer.parseInt(yayaParking.toString()));
                outputStream.close();
            } catch (Exception e) {
                e.printStackTrace();
            }

that should be how it saves the data. I have yet to get this to work, so any help would be appreciated!

Answer 1

You can save it on the sharedPreferences.

    public String getLocation() {
        SharedPreferences pref; = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        return pref.getString("StoredLocation", "");
    }

    public void setLocation(String value) {
        SharedPreferences pref; = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        Editor editor = pref.edit();
        editor.putString("StoredLocation", value);
        editor.commit();
    }

you can store and retrieve location using above code.

Answer 2

Make a global variable of SharedPreference.

SharedPreferences preferences;

Save your data as:

    private void savePreference(String your_data){

    preferences = getSharedPreferences("name_ur_preference", MODE_PRIVATE);
    SharedPreferences.Editor editor = preferences.edit();

    editor.putString("DATA", your_data);

    editor.apply();
}

Answer 3

Use SharedPreference API for small data storage.

SharedPreferences sharedPref = context.getSharedPreferences(
        "lat_pref", Context.MODE_PRIVATE);

    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putString(KEY_LAT, "12.7333");   // your lat and lng
    editor.putString(KEY_LNG, "12.7333");
    editor.commit();

You can retrieve it like below

SharedPreferences sharedPref = context.getSharedPreferences("lat_pref",Context.MODE_PRIVATE);

String slat = sharedPref.getString(KEY_LAT, "0.0");  //0.0 is default value, you can change it to any value you like. This default value is applied when the key is not present in SharedPrefernce

String slng = sharedPref.getString(KEY_LNG, "0.0");

//Convert String Lat and Lng to double values
double lat = Double.parseDouble(slat);
double lng = Double.parseDouble(slng);

You can declare KEY_LAT & KEY_LNG in some constant file.

public static final String KEY_LAT = "latitude";
public static final String KEY_LNG = "longitude";

If you are in Activity then use this as context, if in Fragment then use getActivity()

EDIT

editor.putLong(KEY_LAT, Double.doubleToLongBits(location.getLatitude()));

Retrieve it like,

double lat = Double.longBitsToDouble(sharedPref.getLong(KEY_LAT, 0); 

Do the same for Longitude