Delete duplicates items from my ArrayList of MyModel - arraylist

Question

I tried everything to remove the elements from my array without losing the json data of my SharedPreferences, if I don't add in my HashSet the data that I merged, I get an array without duplicate elements. This is what I want, add my model element without duplications in my array by loading the elements from the Json.
**Here my MyModel :**
public class MyModel {
Integer imageRes;
String textRes;
public MyModel(Integer imageRes, String textRes) {
this.imageRes = imageRes;
this.textRes = textRes;
}
public Integer getImageRes() {
return imageRes;
}
public void setImageRes(Integer imageRes) {
this.imageRes = imageRes;
}
public String getTextRes() {
return textRes;
}
public void setTextRes(String textRes) {
this.textRes = textRes;
}
}
And here my Holder
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.myViewHolder> {
public MyAdapter(ArrayList<MyModel> models) {
this.models = models;
}
private final ArrayList<MyModel> models;
#NonNull
#Override
public myViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.items, parent,false);
return new myViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull myViewHolder holder, int position) {
holder.setIsRecyclable(false);
holder.imageItem.setImageResource(models.get(position).getImageRes());
holder.textItem.setText(models.get(position).getTextRes());
}
public ArrayList<MyModel> getModels() {
return models;
}
#Override
public long getItemId(int position) {
return super.getItemId(position);
}
#Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
#Override
public int getItemCount() {
return (models == null) ? 0 : models.size();
}
#Override
public void setHasStableIds(boolean hasStableIds) {
super.setHasStableIds(hasStableIds);
}
static class myViewHolder extends RecyclerView.ViewHolder{
ImageView imageItem;
TextView textItem;
public myViewHolder(#NonNull View itemView){
super(itemView);
imageItem = itemView.findViewById(R.id.ItemMarker);
textItem = itemView.findViewById(R.id.itemTxt);
}
}
}
**And here my problem :**
if(models != null){
try {
try{
SharedPreferences ListDatas = getSharedPreferences("SavedList", MODE_PRIVATE);
Gson gson = new Gson();
String json = ListDatas.getString("ListKey", null);
Type type = new TypeToken<ArrayList<MyModel>>(){}.getType();
models = gson.fromJson(json, type);
list.setHasFixedSize(true);
if(adapter != null){
adapter.setHasStableIds(true);
}
list.setAdapter(adapter);
list.setBackgroundColor(R.color.items);
list.setDuplicateParentStateEnabled(false);
models.ensureCapacity(100);
adapter = new MyAdapter(models);
NewModel = models;
Set<MyModel> DelItems = new HashSet<>();
DelItems.add(new MyModel(R.drawable.marker, "Commande en cours..." + "\n" + "Date : " + dateFormat + "\n" + "Nettoyage enregistré à : " + heure + "H" + minutes));
Set<MyModel> DelItems2 = new HashSet<>(NewModel);
NewModel.clear();
Set<MyModel> DelItemsFinal = new HashSet<>(DelItems2);
DelItemsFinal.addAll(DelItems2);
DelItemsFinal.addAll(DelItems);
Set<MyModel> DelItemsFinal2 = new LinkedHashSet<>(DelItemsFinal);
NewModel.clear();
NewModel.addAll(DelItemsFinal2);
DelItems.clear();
DelItems2.clear();
adapter.notifyDataSetChanged();
lastPosition = NewModel.size() -1;
layoutManager.scrollToPosition(lastPosition);
InfosHisto.setText("Votre historique de commande");
} catch (JsonSyntaxException e) {
e.printStackTrace();
}