java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.parse.ParseObject

Question

I m currently working on a android apps which fetch data from parse server. I wanted to filter my recyclerView by using searchview. But it shows me nothing while search. It shows me error in this line mRooms = (ArrayList) filterResults.values; Please help me to edit my code regarding this issues.

RoomCardRecyclerViewAdapter

 private List<ParseObject> mRooms = new ArrayList<>();
 private ParseObject room;
 private String mSection;
 private Context context;

 public RoomCardRecyclerViewAdapter(){
    super(DIFF_CALLBACK);
 }
 public static final DiffUtil.ItemCallback<ParseObject>  DIFF_CALLBACK = new 
 DiffUtil.ItemCallback<ParseObject>() {
    @Override
    public boolean areItemsTheSame(@NonNull ParseObject oldItem, @NonNull ParseObject newItem) {
        return oldItem.getObjectId() == newItem.getObjectId();
    }

    @Override
    public boolean areContentsTheSame(@NonNull ParseObject oldItem, @NonNull ParseObject newItem) {
        return (oldItem.getUpdatedAt().equals(newItem.getUpdatedAt()) && 
 oldItem.getCreatedAt().equals(newItem.getCreatedAt()));
    }
};


public RoomCardRecyclerViewAdapter(String section) {
    this();

    this.mSection = section;
}
public RoomCardRecyclerViewAdapter(Context context, List<ParseObject>arrayList) {
    this();

    this.context = context;
    mRooms = arrayList;
     
}


@Override
public RoomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    //inflating the viewholder with the appropriate views
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.room_cardview, parent, 
false);

    return new RoomViewHolder(parent.getContext(), view);
}

@Override
public void onBindViewHolder(@NonNull RoomViewHolder holder, int position) {
    room = getItem(position);

     holder.mRoomLocation.setText(room.getString("roomSuburb"));
    holder.mRoomPrice.setText(Integer.toString(room.getInt("roomMonthlyRent")));
    holder.mInclusiveOrNot.setText(room.getString("roomRentInclusiveOfBills"));
    holder.mPropertyType.setText(room.getString("roomPropertyType"));
    holder.mNumOfBeds.setText(Integer.toString(room.getInt("roomBedrooms")));
    holder.mNumOfBaths.setText(Integer.toString(room.getInt("roomBathrooms")));


  }
  @Override
  public Filter getFilter(){
  return new Filter() {
      @Override
      protected FilterResults performFiltering(CharSequence charSequence) {

FilterResults filterResults = new FilterResults();

          String charString = charSequence.toString();
if (charString.isEmpty()){
     filterResults.values = mRooms;
    filterResults.count = mRooms.size();

}else {
List<ParseObject> filteredList = new ArrayList<>();
for (ParseObject parseObject : mRooms){
    if (parseObject.getString("roomSuburb").toLowerCase().contains(charString.toLowerCase())){
        filteredList.add(parseObject);
    }
}
     filterResults.values = filteredList;
filterResults.count= filteredList.size();
}

return filterResults;

      }

      @Override
      protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
          mRooms = (ArrayList<ParseObject>) filterResults.values;
          notifyDataSetChanged();
      }
  };

}

Answer 1

Define an additional variable mFilteredRooms in the constructor and set it to arrayList

private List<ParseObject> mFilteredRooms = new ArrayList<>();

    public RoomCardRecyclerViewAdapter(Context context, List<ParseObject> arrayList) {
        this();
    
        this.context = context;
        mRooms = arrayList;
        mFilteredRooms = arrayList;
         
    }

Now,

@Override
  public Filter getFilter(){
  return new Filter() {
      @Override
      protected FilterResults performFiltering(CharSequence charSequence) {

          FilterResults filterResults = new FilterResults();
          ArrayList<ParseObject> filteredList = new ArrayList<>();

          
          if (charSequence == null || charSequence.toString().trim().equals("")){
              filteredList.addAll(mFilteredRooms);

          }else {
              String charString = charSequence.toString();
              
              for (ParseObject parseObject : mFilteredRooms){
              if (parseObject.getString("roomSuburb").toLowerCase().contains(charString.toLowerCase())){
                  filteredList.add(parseObject);
               }
          }
          filterResults.values = filteredList;
          filterResults.count= filteredList.size();
      }

      return filterResults;

      }

      @Override
      protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
          mRooms = (List<ParseObject>) filterResults.values;
          notifyDataSetChanged();
      }
  };

Answer 2

You just need to call notifyDataSetChanged() as below -

Use this

 @Override
 protected void publishResults(CharSequence charSequence, FilterResults 
 filterResults) { 
     if (filterResults!= null && results.count > 0) {
         notifyDataSetChanged();
     } else {
         notifyDataSetInvalidated();
     }
 }