RecyclerView duplicate issue in Android

Question

Why does my Android RecyclerView duplicate items by scrolling them?

Here is my Code:

import android.os.Bundle;
    import android.support.v4.app.Fragment;
    import android.support.v7.app.ActionBar;
    import android.support.v7.app.ActionBarActivity;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.support.v7.widget.Toolbar;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ImageView;
    import android.widget.TextView;
    import android.widget.Toast;

    import java.util.ArrayList;
    import java.util.Arrays;





    public class Fragment1 extends Fragment {
    RecyclerView rv1;
        TextView rvtvheadline;
        TextView rvtvdescription;
        ImageView rvivicon;
        String[] headlinervtext = {"Eintrag 1", "Eintrag 2", "Eintrag 3"};
        String[] descriptionrv = {"Beschreibung 1","Beschreibung 2","Beschreibung 3"};
        int[] iconsrv = {R.drawable.ic_attach_file_grey600_24dp, R.drawable.ic_format_color_reset_grey600_24dp, R.drawable.ic_format_paint_grey600_24dp};
        ArrayList<String> headlinerv = new ArrayList<>();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment

        return inflater.inflate(R.layout.fragment_fragment1, container, false);

    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {


        //    recyclerviewsetup();



        super.onActivityCreated(savedInstanceState);


    }

    @Override
    public void onHiddenChanged(boolean hidden) {

       if(hidden == true){
          //  rv1= null;
       }

        super.onHiddenChanged(hidden);
    }

    public void recyclerviewsetup(){
        headlinerv.addAll(Arrays.asList(headlinervtext));

        rv1 = (RecyclerView) getView().findViewById(R.id.rv1);
        rv1.setLayoutManager(new LinearLayoutManager(getActivity()));
        rv1.setOverScrollMode(View.OVER_SCROLL_ALWAYS);
        rv1.setAdapter(new RecyclerView.Adapter() {
            @Override
            public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
                final View itemview1 = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.rv_item_layout1, viewGroup, false);

                rvtvheadline = (TextView) itemview1.findViewById(R.id.textViewrv1);
                rvtvdescription = (TextView) itemview1.findViewById(R.id.textViewrv2);
                rvivicon = (ImageView) itemview1.findViewById(R.id.imageViewrv1);

                itemview1.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        switch (rv1.getChildAdapterPosition(itemview1)) {
                            case 0: {
                                Toast.makeText(getActivity(), "Item 1", Toast.LENGTH_SHORT).show();

                                break;
                            }
                            case 1: {
                                Toast.makeText(getActivity(), "Item 2", Toast.LENGTH_SHORT).show();
                                break;
                            }
                            case 2: {
                                Toast.makeText(getActivity(), "Item 3", Toast.LENGTH_SHORT).show();
                                break;
                            }
                        }
                    }
                });




                return new RecyclerView.ViewHolder(itemview1) {
                };

            }

            @Override
            public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int i) {

                rvtvheadline.setText(headlinerv.get(i));
                rvtvdescription.setText(descriptionrv[i]);
                rvivicon.setImageResource(iconsrv[i]);


            }

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


        });

    }


}

If I have many Items they just duplicate by scrolling. Do you have an idea why?

I have tried out this: public long getItemId(int position){ return position}

But this don't resolve my Problem.