ManagedDataHelper is a Helper class that gives you the ability to override strings (or array of strings) saved on Android Resources (xml) with data from a remote JSON document.

ManagedDataHelper.java

public class ManagedDataHelper {
	static ManagedDataHelper sSelf = null;
	static final String SHARED_PREFERENCES_FILENAME = "managed_data";
	Context mContext;
	Resources mResources;
	SharedPreferences mSharedPreferences;

	private ManagedDataHelper(Context context) {
		mContext = context;
		mResources = mContext.getResources();
		mSharedPreferences = mContext.getSharedPreferences(
				SHARED_PREFERENCES_FILENAME, 0);
	}

	public static ManagedDataHelper factory(Context context) {
		if (sSelf == null) {
			sSelf = new ManagedDataHelper(context);
		}
		return sSelf;
	}

	public String getString(String key) {
		String value = null;

		boolean hasKey = mSharedPreferences.contains(key);

		if (hasKey) {
			value = mSharedPreferences.getString(key, null);
			if (value != null) {
				return value;
			}
		}

		return value;
	}

	public String getString(String key, String defVal) {
		String value = getString(key);

		if (value != null) {
			return value;
		} else {
			return defVal;
		}
	}

	/*
	 * If resourceID is zero 0 then we try to find the string resource with the
	 * same name, it is better to use resourceID for speed reasons
	 */
	public String getString(String key, int resourceID) {
		String value = getString(key);

		if (value == null) {
			if (resourceID == 0) {
				// try to find the resID from key name
				resourceID = mResources.getIdentifier(key, "string",
						mContext.getPackageName());
			}

			if (resourceID > 0) {
				value = mResources.getString(resourceID);
			}
		}

		return value;
	}

	public String[] getStringArray(String key) {
		String[] values = null;

		boolean hasKey = mSharedPreferences.contains(key);

		if (hasKey) {

			String json = mSharedPreferences.getString(key, null);

			if (json != null) {
				try {
					JSONArray a = new JSONArray(json);
					values = new String[a.length()];
					for (int i = 0; i < a.length(); i++) {
						values[i] = a.optString(i);
					}
				} catch (JSONException e) {
					e.printStackTrace();

				}
			}
		}

		return values;
	}

	/*
	 * If resourceID is zero 0 then we try to find the string resource with the
	 * same name, it is better to use resourceID for speed reasons
	 */
	public String[] getStringArray(String key, int resourceID) {
		String[] values = getStringArray(key);

		if (values == null) {
			if (resourceID == 0) {
				// try to find the resID from key name
				resourceID = mResources.getIdentifier(key, "string",
						mContext.getPackageName());
			}

			if (resourceID > 0) {
				values = mResources.getStringArray(resourceID);
			}
		}

		return values;
	}

	public void updateData(JSONObject json) {

		Editor editor = mSharedPreferences.edit();
		if (json != null) {
			Iterator<String> it = json.keys();
			String key = null;

			while (it.hasNext()) {
				String value = null;
				key = it.next();

				// if value is null then remove the key from xml
				if (json.isNull(key)) {
					editor.remove(key);
				} else {

					// try to see if it is an array of strings
					try {
						JSONArray jsonArray = json.getJSONArray(key);
						editor.putString(key, jsonArray.toString());
					} catch (Exception e) {
						value = null;
					}

					if (value == null) {
						try {
							value = json.getString(key);
							if (value != null) {
								editor.putString(key, value);
							}
						} catch (Exception e) {

							value = null;

						}
					}
				}

			}

			editor.apply();
		}
	}
}