My Object Is Not Null But I'm Getting A Null Pointer Exception

For some reason I am getting a null pointer exception pointing to videosFound when it is indeed not null. Even the parameter, adapter, that is being passed in is not null. I check

Solution 1:

In the stacktrace I see this:

java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference

The adapter is trying to call size() on a null List. Make sure your list searchResults is not null.

Solution 2:

NullPointerException occurred because searchResults is not initialized and is null. Regarding your question in the comment -

do you know why the error did not actually point to the line where searchResults was?

ArrayAdapter calls getCount() internally whenever you call setAdapter() or refresh the already created adapter using notifyDataSetChanged(). Till you call setAdapter() or notifyDataSetChanged(), ArrayAdapter won't create view for you and in order to create that, it needs to check the size of the data which you passed to it. For that it calls getCount() which is

publicintgetCount() {
        return mObjects.size();
    }

where mObjects is initialized to the data list which you pass while creating your adapter.

Apparently mObjects.size() will throw NullPointerException since mObjects is null because searchResults is null.

Hope you understood.