How to retrieve SharedPreferences string? - android-studio

Question

While working on an android app, I discovered, that I would have to use SharedPreferences to store login data (url, port, name), but since I am new to this, I am not sure, how to access the data for MQTT to use those inputs and login.
in tab3_fragment.java, the SharedPreferences get set this way:
public void saveData(){
SharedPreferences userDetails = (SharedPreferences) getContext().getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = userDetails.edit();
editor.putString(url, input_url.getText().toString());
editor.putString(port, input_port.getText().toString());
editor.apply();
Toast.makeText(getActivity(), "Einstellungen gespeichert", Toast.LENGTH_SHORT).show();
}
public void loadData(){
SharedPreferences userDetails = getContext().getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
text_url = userDetails.getString(url, " ");
text_port = userDetails.getString(port, " ");
}
This is how I try to access the SharedPreferences:
public MqttHelper(Context context){
SharedPreferences userDetails = getContext().getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
final String url = userDetails.getString(tab3_fragment.url, " ");
final String port = userDetails.getString(tab3_fragment.port, " ");
String strArray2[] = {url, port};
String serverUri = TextUtils.join(":", strArray2);
Toast.makeText(getActivity(), serverUri, Toast.LENGTH_SHORT).show();
When running the above code from within another fragments onCreateView, it runs fine, but when I add the code to the MqttHelper.java, so that it can load the settings, it returns error
cannot resolve method `getContext()`.
How can I make the MqttHelper access the SharedPreferences?

Answer 1

When running the above code from within another fragments onCreateView, it runs fine, but when I add the code to the MqttHelper.java, so that it can load the settings, it returns error
cannot resolve method getContext().
As I can see in your code you are passing the context already by parameter, so I don't see any need to use getContext() there, you can easy use context
Bad
public MqttHelper(Context context){
SharedPreferences userDetails = getContext().getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
Good
public MqttHelper(Context context){
SharedPreferences userDetails = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
Also I'm seeing that you are displaying a Toast using getActivity() you can use also getActivity() to get the context as an alternative.