버튼을 두번씩 눌러야 실행이 되고 값을 입력 안하면 첫번째 if문에 걸려서 toast를 출력해줘야하는데 되지가 않습니다..... 왜그런건가요...? 코드상 문제는 없어보여서 부탁드립니다!!

public class kakao extends AppCompatActivity implements MapView.POIItemEventListener {

private Button btn_find;
private EditText input; 
private MapView mapView ;
private int i,tag;
private ArrayList<MapPOIItem> markerlist;
private ArrayList<MarkerInfo> markerinfo;
private int count;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_kakao);

    btn_find = findViewById(R.id.btn_place2);
    input = findViewById(R.id.input_place2);

    mapView= new MapView(this);
    ViewGroup mapViewContainer = (ViewGroup) findViewById(R.id.map_view2);
    mapViewContainer.addView(mapView);

    markerlist = new ArrayList<MapPOIItem>();
    markerinfo = new ArrayList<MarkerInfo>();
    markerlist.clear();
    markerinfo.clear();

    btn_find.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(input.getText()==null){
                Toast.makeText(kakao.this, "장소를 입력하세요!", Toast.LENGTH_SHORT).show();
            }
            else{
                int tagindex=0;
                if(false==markerlist.isEmpty()){

                    for(i=0;i<markerlist.size();i++){
                        mapView.removePOIItem(markerlist.get(i));
                    }
                    markerlist.clear();
                    markerinfo.clear();
                }
                MarkerInfoCall();


                for(i=0;i<markerinfo.size();i++) {
                    MapPoint centpoint =  MapPoint.mapPointWithGeoCoord(markerinfo.get(0).lat,markerinfo.get(0).lng);
                    mapView.setMapCenterPoint(centpoint, true);
                    MapPoint mapPoint = MapPoint.mapPointWithGeoCoord(markerinfo.get(i).lat, markerinfo.get(i).lng);
                    MapPOIItem marker = new MapPOIItem();
                    marker.setItemName(markerinfo.get(i).name);
                    marker.setMapPoint(mapPoint);
                    marker.setTag(tagindex);
                    marker.setShowCalloutBalloonOnTouch(false);
                    marker.setShowAnimationType(MapPOIItem.ShowAnimationType.SpringFromGround);
                    marker.setMarkerType(MapPOIItem.MarkerType.YellowPin); // 기본으로 제공하는 BluePin 마커 모양.
                    marker.setSelectedMarkerType(MapPOIItem.MarkerType.BluePin); // 마커를 클릭했을때, 기본으로 제공하는 RedPin 마커 모양.
                    mapView.addPOIItem(marker);

                    markerlist.add(marker);
                    tagindex++;
                }


            }

        }
    });




    MapPoint mapPoint = MapPoint.mapPointWithGeoCoord(37.53737528, 127.00557633);
    mapView.setMapCenterPoint(mapPoint, true);
    mapView.setPOIItemEventListener(this);


}
public void onPOIItemSelected(MapView mapView, MapPOIItem mapPOIItem) {
        String place_name = mapPOIItem.getItemName();
        tag = mapPOIItem.getTag();
        showAlertDialog(place_name);

}

@Override
public void onCalloutBalloonOfPOIItemTouched(MapView mapView, MapPOIItem mapPOIItem) {

}

@Override
public void onCalloutBalloonOfPOIItemTouched(MapView mapView, MapPOIItem mapPOIItem, MapPOIItem.CalloutBalloonButtonType calloutBalloonButtonType) {

}

@Override
public void onDraggablePOIItemMoved(MapView mapView, MapPOIItem mapPOIItem, MapPoint mapPoint) {

}

private void showAlertDialog(String place_name){

    AlertDialog.Builder builder = new AlertDialog.Builder(kakao.this);
    LayoutInflater inflater = getLayoutInflater();
    View view =  inflater.inflate(R.layout.map_info,null);
    builder.setView(view);

    TextView title = view.findViewById(R.id.map_title);
    TextView addr = view.findViewById(R.id.map_addr);
    Button btn_road = view.findViewById(R.id.btn_road);
    Button btn_info = view.findViewById(R.id.btn_info);
    Button btn_call = view.findViewById(R.id.btn_call);
    final AlertDialog dialog = builder.create();
    title.setText(place_name);
    addr.setText(markerinfo.get(tag).address);

    btn_call.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(Intent.ACTION_DIAL, Uri.parse("tel:"+markerinfo.get(tag).phone)));
        }
    });

    btn_road.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(kakao.this, "kkkk", Toast.LENGTH_SHORT).show();
        }
    });

    btn_info.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(kakao.this, Web_Place_Info.class);
            intent.putExtra("url",markerinfo.get(tag).link);
            startActivity(intent);
        }
    });


    dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
    dialog.getWindow().requestFeature(Window.FEATURE_NO_TITLE);
    dialog.getWindow().setGravity(Gravity.BOTTOM);
    dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
    dialog.show();
}

private void MarkerInfoCall(){

    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl("https://dapi.kakao.com")
            .addConverterFactory(GsonConverterFactory.create())
            .build();

    String KaKaoAK = "KakaoAK ㅌㅌㅌㅌㅌㅌ";
    String query = String.valueOf(input.getText());

    KaKaoInterface service = retrofit.create(KaKaoInterface.class);
    Call<KaKaoRepo> call =service.kakaorepo(KaKaoAK,query);
    call.enqueue(new Callback<KaKaoRepo>() {
        @Override
        public void onResponse(Call<KaKaoRepo> call, Response<KaKaoRepo> response) {
            Log.d("sssssss", String.valueOf(response.code()));
            if(response.isSuccessful()){
                Log.d("dddddd", String.valueOf(response.code()));
                KaKaoRepo result = response.body();

                if(result.documents.length != 0){
                    int count = result.meta.getTotal_count();
                    if(count>15){
                        count=15;
                    }
                    for(i=0;i<count;i++){

                        MarkerInfo mki = new MarkerInfo();

                        mki.setAddress(result.documents[i].getRoad_address_name());
                        mki.setCategory(result.documents[i].getCategory_name());
                        mki.setName(result.documents[i].getPlace_name());
                        mki.setPhone(result.documents[i].getPhone());
                        mki.setLink(result.documents[i].getPlace_url());
                        mki.setLng(result.documents[i].getX());
                        mki.setLat(result.documents[i].getY());

                        markerinfo.add(mki);


                    }

                    Log.d("사이즈", String.valueOf(markerinfo.size()));

                }
                else{
                    Toast.makeText(kakao.this, "No Data", Toast.LENGTH_SHORT).show();
                }

            }
            else{
                  Toast.makeText(kakao.this, "API Error", Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void onFailure(Call<KaKaoRepo> call, Throwable t) {
            Log.e("에러", String.valueOf(t));
        }
    });

}

}