Getting data in recyclerView

Question

i am getting messages from the database into a recycler view but i want to refresh the recycler view every second for to adding different for to getting new messages in recycler view

But i haver an error of getting data please see it https://www.filemail.com/d/izhittgyibvcjxx

my code is

boolean refresh;

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_message_user);


        refresh = true;
        content();
    }

public void content()
    {
        getdata();
        if (refresh)
        {
            refresh(100);
        }
    }

    private void refresh(int milliseconds)
    {
        final Handler handler = new Handler();
        final Runnable runnable = new Runnable() {
            @Override
            public void run() {
                content();
            }
        };

        handler.postDelayed(runnable,milliseconds);
    }


private void getdata()
    {
        String Choice = "Get Messages";
        Call<List<responsemodel>> call = SplashScreen.apiInterface.getfullprofiledata(Choice,Message_To,Message_From);
        call.enqueue(new Callback<List<responsemodel>>() {
            @Override
            public void onResponse(Call<List<responsemodel>> call, Response<List<responsemodel>> response) {
                List<responsemodel> data = response.body();
                Message_user_Adapter adapter = new Message_user_Adapter(data,Message_To);
                messages_Message_user_RecyclerView.setAdapter(adapter);

                messages_Message_user_RecyclerView.smoothScrollToPosition(messages_Message_user_RecyclerView.getAdapter().getItemCount());
            }

            @Override
            public void onFailure(Call<List<responsemodel>> call, Throwable t) {

            }
        });
    }