Best place for storing user login credentials in Android

Question

I am creating an android app, and i cannot(?) find any information on authenticating a user of the app on Google App Engine (without using the user\'s Google Account).Is it

Answer 1

Consider SharedPreferences for this, like...

public class PrefUtils {
    public static final String PREFS_LOGIN_USERNAME_KEY = "__USERNAME__" ;
    public static final String PREFS_LOGIN_PASSWORD_KEY = "__PASSWORD__" ;

    /**
     * Called to save supplied value in shared preferences against given key.
     * @param context Context of caller activity
     * @param key Key of value to save against
     * @param value Value to save
     */
    public static void saveToPrefs(Context context, String key, String value) {
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
        final SharedPreferences.Editor editor = prefs.edit();
        editor.putString(key,value);
        editor.commit();
    }

    /**
     * Called to retrieve required value from shared preferences, identified by given key.
     * Default value will be returned of no value found or error occurred.
     * @param context Context of caller activity
     * @param key Key to find value against
     * @param defaultValue Value to return if no data found against given key
     * @return Return the value found against given key, default if not found or any error occurs
     */
    public static String getFromPrefs(Context context, String key, String defaultValue) {
        SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
        try {
            return sharedPrefs.getString(key, defaultValue);
        } catch (Exception e) {
             e.printStackTrace();
             return defaultValue;
        }
    }
}

Simply use these methods like,

// Saving user credentials on successful login case
PrefUtils.saveToPrefs(YourActivity.this, PREFS_LOGIN_USERNAME_KEY, username);
PrefUtils.saveToPrefs(YourActivity.this, PREFS_LOGIN_PASSWORD_KEY, password);

// To retrieve values back
String loggedInUserName = PrefUtils.getFromPrefs(YourActivity.this, PREFS_LOGIN_USERNAME_KEY);
String loggedInUserPassword = PrefUtils.getFromPrefs(YourActivity.this, PREFS_LOGIN_PASSWORD_KEY);

I think its much clearer now...:)