Data not inserting into the Database room Android - database

Question

I'm new to android and this is the first time I'm using room in my application. Either insert operation is not performed or the database is not created or any other error.
I don't know what I'm doing wrong so I need your help.
This program is running but No result is displayed. Nothing is showing on the screen.
Here is my code-
please let me know what is wrong in this code and what I should do to correct it.
Car_details.java
#PrimaryKey
#NonNull
#SerializedName("id")
#Expose
private String id;
#SerializedName("name")
#Expose
private String name;
#SerializedName("desc")
#Expose
private String desc;
#SerializedName("image")
#Expose
private String image;
CarDao.java-
#Insert(onConflict = OnConflictStrategy.REPLACE)
void insert(Car_Details car_details);
#Query("Select * from car_table")
LiveData<List<Car_Details>> selectAll();
CarListDatabase.java
private static CarListDatabase instance;
public abstract CarDao carDao();
public static synchronized CarListDatabase getInstance(Context context){
if(instance==null)
{
instance= Room.databaseBuilder(context.getApplicationContext(),
CarListDatabase.class,"Car_database").fallbackToDestructiveMigration()
.build();
}
return instance;
}
CarRepository.java
public void getCarList(){
CarlistInterface carlistInterface= retrofit.create(CarlistInterface.class);
Call<List<Car_Details>> carList= carlistInterface.carList();
carList.enqueue(new Callback<List<Car_Details>>() {
#Override
public void onResponse(Call<List<Car_Details>> call, final Response<List<Car_Details>> response) {
if(response.body() != null){
List<Car_Details> car_details = response.body();
for (int i = 0; i < car_details.size(); i++) {
String id=car_details.get(i).getId();
String names = car_details.get(i).getName();
String desc=car_details.get(i).getDesc();
String image= car_details.get(i).getImage();
Car_Details car = new Car_Details();
car .setId(id);
car .setName(names);
car .setDesc(desc);
car .setImage(image);
new InsertNoteAsyncTask(carDao).execute(car);
}
}
}
});
}
public LiveData<List<Car_Details>> getCarLists(){
return allCarList;
}
private static class InsertNoteAsyncTask extends AsyncTask<Car_Details,Void,Void> {
private CarDao carDao;
private InsertNoteAsyncTask(CarDao carDao){
this.carDao= carDao;
}
#Override
protected Void doInBackground(Car_Details... car_details) {
carDao.insert(car_details[0]);
return null;
}
CarViewModel.java
public CarViewModel(#NonNull Application application) {
super(application);
repository= new CarRepository(application);
carList= repository.getCarLists();
}
public LiveData<List<Car_Details>> getListLiveData() {
return carList;
MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
repository = new CarRepository(this);
carViewModel = ViewModelProviders.of(this).get(CarViewModel.class);
recyclerView= findViewById(R.id.cars_recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
List = new ArrayList<>();
recyclerAdapter = new RecyclerAdapter(List);
recyclerView.setAdapter(recyclerAdapter);
recyclerAdapter = new RecyclerAdapter(List);
recyclerView.setAdapter(recyclerAdapter);
carViewModel.getListLiveData().observe(this, new
Observer<java.util.List<Car_Details>>() {
#Override
public void onChanged(java.util.List<Car_Details> car_details) {
recyclerAdapter.setUserList(List);
}
});
repository.getCarList();
}
RecyclerAdapter.java
public class RecyclerAdapter extends RecyclerView.Adapter {
List<Car_Details> carList= new ArrayList<>();
public RecyclerAdapter(List<Car_Details> carList) {
this.carList = carList;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater= LayoutInflater.from(parent.getContext());
View view= layoutInflater.inflate(R.layout.row_item,parent,false);
return new RecyclerAdapter.ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
holder.car_name.setText(carList.get(position).getName());
holder.car_desc.setText(carList.get(position).getDesc());
}
public void setUserList(List<Car_Details> userList) {
this.carList = userList;
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return carList.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
private TextView car_name,car_desc;
public ViewHolder(#NonNull View itemView) {
super(itemView);
car_name= itemView.findViewById(R.id.car_name);
car_desc= itemView.findViewById(R.id.car_desc);
}
}
}
#Override
public int getItemCount() {
return carList.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
private TextView car_name,car_desc;
public ViewHolder(#NonNull View itemView) {
super(itemView);
car_name= itemView.findViewById(R.id.car_name);
car_desc= itemView.findViewById(R.id.car_desc);
}
}
}

Answer 1

There is nothing wrong with your insert operation with room.
The way you have used live date in your application seems wrong that's why your program is running but no result is coming.
You have to check the part where you are using live data.
Hope this help you out.