Android NPE while second calling interface

Question

I have some class application class extending Application. I use it as a controller for filling the database and perfoming REST calls. There is an interface:

private OnDBfilled onFilledListener;
...
public void setOnFilledListener(OnDBfilled onFilledListener) {
    this.onFilledListener = onFilledListener;
}
public interface OnDBfilled {
    void onFilledCallback();
}
...

When I've got required data call it to get known the Fragment, that data was successfully load from the internet and filled to database:

@Override
        public void onResponse(Call call, Response response) throws IOException {
...//working with data
onFilledListener.onFilledCallback();
}

For the first time, when the call is done and database is filled I can see the result in the log:

private Application controller;
private Application.OnDBfilled listener;
...
controller = new Application();
listener = new Application.OnDBfilled() {
        @Override
        public void onFilledCallback() {
            System.out.println("bd is filled. replacing fragments initiated editianal");
            replaceFragment();
        }
    };
 controller.setOnFilledListener(listener);

This works fine and I can see the logging message. But when I'm trying to do in the another fragment, I've got Null Pointer Exception in this line:

 onFilledListener.onFilledCallback();

Here's code of another fragment, but it's almost equal:

  private Application controller;
private Application.OnDBfilled filledDBListener;

...
//onCreateView
controller = new Application();
    filledDBListener = new Application.OnDBfilled() {
        @Override
        public void onFilledCallback() {
            swipeRefreshLayout.setRefreshing(false);
           // fillEventListFromBD(UserData.getCity(getActivity()));
        }
    };
    controller.setOnFilledListener(filledDBListener);

Any suggestions? Thanks!

Possible duplicate of [What is a NullPointerException, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — Janki Gadhiya, Jul 05 '16 at 11:43

loadjang · Accepted Answer · 2016-07-05T13:09:02.107

1

OnDBfilled flid static

 private static OnDBfilled onFilledListener;

or

fragment & viewpager use:

 viewpager.setoffscreenpagelimit(9)

edited Jul 05 '16 at 13:09

answered Jul 05 '16 at 11:52

loadjang

327
1
3

Did you even read the question? Quoted from the question: 'I've got Null Pointer Exception in this line: `onFilledListener.onFilledCallback();`' – 0xDEADC0DE Jul 05 '16 at 11:55

Android NPE while second calling interface

1 Answers1