Recyclerview: can't get the item count value - android-recyclerview

Question

im newbie here... I have a problem in getting the item count on my recyclerview? I've try this code but it's not working.
int count = 0;
if (recyclerViewInstance.getAdapter() != null) {
count = recyclerViewInstance.getAdapter().getItemCount();
}
also this one but it's not working too..
int count = 0;
if (mAdapter != null) {
count = mAdapter.getItemCount();
}
this is my code:
mainActivity:
private List<NavDrawerFleetGetterSetter> navList= new ArrayList<>();
private RecyclerView recyclerView;
private NavDrawerFleetAdapter mAdapter;
Button add;
TextView successCount;
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nav_drawer_fleet);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
add = findViewById(R.id.fab);
successCount=findViewById(R.id.count);
recyclerView =findViewById(R.id.nav_sent);
mAdapter = new NavDrawerFleetAdapter(navList);
RecyclerView.LayoutManager mLayoutManager = new
LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setAdapter(mAdapter);
if (recyclerView.getAdapter() != null) {
successCount.getText(recyclerViewInstance.getAdapter().getItemCount());
}
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
NavDrawerFleetGetterSetter navD= new
NavDrawerFleetGetterSetter(lati,longi,dateTime);
navList.add(navD);
mAdapter.notifyDataSetChanged();
}
myGetterSetter:
public class NotSentModuleGetterSetter {
String lat,lon,dateTime;
public NotSentModuleGetterSetter(String lat, String lon, String dateTime) {
this.lat = lat;
this.lon = lon;
this.dateTime = dateTime;
}
public String getLat() {
return lat;
}
public void setLat(String lat) {
this.lat = lat;
}
public String getLon() {
return lon;
}
public void setLon(String lon) {
this.lon = lon;
}
public String getDateTime() {
return dateTime;
}
public void setDateTime(String dateTime) {
this.dateTime = dateTime;
}
}
myOutput:
as you see, the success count was turned into zero.
btw, my data was getting on my database and i was pickup the code need since i have a bunch of codes as for now for my project.
an also, using debug, the data of my mAdapter=null.

Answer 1

In this case, i was getting the count data on my adapter but it should be get the "Size" of adapter than getting the "count". It is now working on me. :)