Android: getContext().getContentResolver() sometimes gets NullPointerException

Ok it seems I fixed it myself by declaring Context on the beggining of the class.

public class NoteProvider extends ContentProvider {
    Context context;

then initializing it in onCreate()

@Override
    public boolean onCreate() {
        mSQLiteOpenHelper = new NoteDbHelper(getContext());
        context = getContext();

        return true;
    }

I think that made sure that I always have Context when I use context.getContentResolver().notifyChange(uri, null); or retCursor.setNotificationUri(context.getContentResolver(), uri); in insert/update/delete/query method- retCursor being returned cursor by mentioned methods.

I have run the aplication on my phone and did not have issues yet if I will there will probably be an edit for this post.

EDIT:

It does not make a difference after all - explanationin answer by @Mate, thank you for that I think I get it now :]


Write getApplicationContext().getContentResolver() Hope this will work.


If you can make sure that getContext() can never be null then you can simply ignore this warning. I think the warning even disappears of you just check for null:

if (getContext() != null) {
    getContext().getContentResolver();
}

You just have to keep in mind the code won't be executed if getContext() is null.

Cheers

edit: Be careful with the answer @Shivani Gupta gave you, because you could get different contexts. See: Difference between getContext() , getApplicationContext() , getBaseContext() and "this"


If you look in the source of ContentProvider (just hold SHIFT and click on the classname in Android Studio) then you will find that the implementation is holding an object of type Context as mContext.

Your solution is just the same, which means if mContext of ContentProvider is null, your reference will also be null. So there is no need for this.

To help you out, this is just a warning of your IDE if make such a construct yourself. But in this case there will always be context, because the ContentProvider is generated by your system. To avoid the error in your IDE just write @SuppressWarnings("ConstantConditions") above your class definition like:

...
@SuppressWarnings("ConstantConditions")
public class NoteProvider extends ContentProvider {
...