Casting error in ArrayList<Object>

I needed an Arraylist which can hold multiple types of content, browsing some questions on Stackoverflow, I found that ArrayList<Object> arrayList = new ArrayList<>(); can do the trick. But when I tried to use the arraylist it throws an casting error.

This is my code. (error commented in 5th line)

private ArrayList<Object> arrayList = new ArrayList<>();

public RecyclerViewAdapter(Context context, ArrayList<CardSetterGetter> arrayList, ArrayList<String> favouriteItemList, int totalCount) {
    this.context = context;
    this.arrayList = arrayList; //Incompatible types.  Required: ArrayList<java.lang.object>;    found: ArrayList<com.comp.app.modal.CardSetterGetter>
    this.favouriteItemList = favouriteItemList;
    this.totalCount = totalCount;

}

asked Sep 28 '17 at 22:32

Ishan hrx

If your list is read-only, you can use `ArrayList>`. – shmosel Sep 28 '17 at 22:36
no it's not read-only, i am trying to parse a json file, and also put ads in between. so there will be two kind of stuff into this. "Ads" and the "actual content". – Ishan hrx Sep 28 '17 at 22:41
Then you'll have to copy the list: `this.arrayList = new ArrayList<>(arrayList);` – shmosel Sep 28 '17 at 22:43
@shmosel can you please explain a little about this approach? Also, do i have to put this code in `RecyclerViewAdapter` body or before that only? – Ishan hrx Sep 28 '17 at 22:47
@shmosel this is throwing the same error BTW – Ishan hrx Sep 28 '17 at 22:48
See the duplicate question for details. It would be in place of the line with the error. – shmosel Sep 28 '17 at 22:49
Alternatively, you can do `this.arrayList.addAll(arrayList);`. – shmosel Sep 28 '17 at 22:49

0 Answers0