how to select all checkboxes true on button click

i have created one recycler view in which i have putted checkboxes on select all button all check should be true.The problem is that i have created select all in fragment and my checkboxes are in adapter. In my main fragment xml i have putted the select all button and recycler view and in adapter i have putted the checkboxes. my code is

public class SearchFragment extends BaseFragment {
 Object arr;
 ArrayList<String> arrayList = new ArrayList<>();
 public TextView tv2;

 public RecyclerView rvList;
 Context context;
 public static SearchFragment newInstance () {
    return new SearchFragment();
 }

 @Override
  public View onCreateView (LayoutInflater inflater, ViewGroup container,
                          Bundle savedInstanceState) {
  View view = inflater.inflate(R.layout.fragment_search, container, false);
   tv2=(TextView) view.findViewById(R.id.tv2);
    rvList=(RecyclerView)view.findViewById(R.id.rvList);
    arrayList = new ArrayList<>();
    for (int i = 0; i < 10; i++){
        arrayList.add("Produk " + i);
    }
    LinearLayoutManager layoutManager = new 
    LinearLayoutManager(getContext());

    rvList.setLayoutManager(layoutManager);

    MyAdapter mAdapter = new MyAdapter(getContext(),arrayList);

    // 4. set adapter
    rvList.setAdapter(mAdapter);
    // 5. set item animator to DefaultAnimator
    rvList.setItemAnimator(new DefaultItemAnimator());


     return view;
     }

    @Override
    public void onViewCreated (View view, @Nullable Bundle 
    savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    ButterKnife.bind(this, view);

     }
    @OnClick({R.id.txtFilter})
    public void onClick (View view) {
    switch (view.getId()) {
    case R.id.txtFilter:
     startIntent(FilterActivity.class);
     getActivity().overridePendingTransition(R.anim.left_in, R.anim.plain);
            break;
    }
     }
    public class  MyAdapter extends 
    RecyclerView.Adapter<MyAdapter.MyViewHolder> { private HashMap<Integer, 
    Boolean> isChecked = new HashMap<>();
    private Context mContext;
    private LayoutInflater inflater;
    ArrayList<String> arrayList = new ArrayList<>();

public MyAdapter(Context context, List<String> arrayList){
        this.mContext = context;
        this.arrayList = (ArrayList<String>) arrayList;
        inflater = LayoutInflater.from(context);
    }

public MyAdapter(ArrayList<String> arrayList) {
 }

    @Override
    public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int 
     viewType) {
        View rootView = inflater.inflate(R.layout.list_item_produt, parent, 
     false);

        MyViewHolder holder = new MyViewHolder(rootView);
        return holder;
    }


    @Override
    public void onBindViewHolder(MyAdapter.MyViewHolder holder, int 
    position) {
        holder.cbProduk.setText(arrayList.get(position));
        if (isChecked.containsKey(position)){
            holder.cbProduk.setChecked(isChecked.get(position));
        } else {
            holder.cbProduk.setChecked(false);
        }
    }

    @Override
    public int getItemCount() {
        return arrayList.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {

        CheckBox cbProduk;

        public MyViewHolder(View itemView) {
            super(itemView);

            cbProduk = (CheckBox) itemView.findViewById(R.id.cbProduk);

            cbProduk.setOnCheckedChangeListener(new 
      CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, 
      boolean isChecked) {
                    if (isChecked){
                        // KONDISI PADA SAAT CEKLIS
                        Toast.makeText(mContext, "checklist", 
      Toast.LENGTH_SHORT).show();
                    } else {
                        // KONDISI PADA SAAT CEKLIS DIHILANGKAN
                        Toast.makeText(mContext, "unchecklist", 
      Toast.LENGTH_SHORT).show();
                    }
                }
            });
        }
    }
}

}