Я получаю сообщение об ошибке:
12378-12378 / info.androidhive.firebase W / ClassMapper: не найдено установщика / поля для artistName в классе info.androidhive.firebase.Artist2
Данные записываются в базу данных Firebase, но не отображаются в ListView.
Пожалуйста, смотрите мой код ниже:
import android.widget.TextView;
import java.util.List;
public class ArtistList2 extends ArrayAdapter<Artist2> {
private Activity context; //context activity
private List<Artist2> artistList2; //list will store all the artists
//constructor parsing context and artist list
public ArtistList2(Activity context, List<Artist2> artistList2) {
super(context, R.layout.list_layout2, artistList2); //passing context, layout file and the artist list
this.context = context; //initialising variables
this.artistList2 = artistList2;
}
@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) { //over ride get view method
LayoutInflater inflater = context.getLayoutInflater(); //layout inflator object
View listViewItem = inflater.inflate(R.layout.list_layout2,null,true); //creating list view object to inflate the xml list layout
TextView textViewName2 = (TextView) listViewItem.findViewById(R.id.textViewName2); //create text view for the name
TextView textViewGenre2 = (TextView) listViewItem.findViewById(R.id.textViewGenre2); //create text view for the genres
Artist2 artist2 = artistList2.get(position);
//Artist artist2 = artistList2.get(position); //gets the artists particular position
textViewName2.setText(artist2.getArtistName2()); //set name value to the corresponding text view
textViewGenre2.setText(artist2.getArtistGenre2()); //set genre value to the corresponding text view
return listViewItem;
}
}
пакет info.androidhive.firebase;
открытый класс Artist2 {
String artistId2;
String artistName2;
String artistGenre2;
public Artist2(){}
public Artist2(String artistId2, String artistName2, String artistGenre2) {
this.artistId2 = artistId2;
this.artistName2 = artistName2;
this.artistGenre2 = artistGenre2;
}
public String getArtistId2() {
return artistId2;
}
public String getArtistName2() {
return artistName2;
}
public String getArtistGenre2() {
return artistGenre2;
}
}
открытый класс WishListActivity расширяет AppCompatActivity {
//Declarations of variables
EditText editTextName2;
Button buttonAdd2;
Spinner spinnerGenres2;
//Database reference object
DatabaseReference databaseArtists2;
//Declaration of list view for the adapter
ListView listViewArtists2; //retrieves this from the xml
List<Artist2> artistList2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_wish_list2);
//gets the database reference object and passes artists - the parameter
databaseArtists2 = FirebaseDatabase.getInstance().getReference("artists2");
//Declarations of textviews, buttons and spinners
editTextName2 = (EditText) findViewById(R.id.editTextName2);
buttonAdd2 = (Button) findViewById(R.id.buttonAddArtist2);
spinnerGenres2 = (Spinner) findViewById(R.id.spinnerGenres2);
listViewArtists2 = (ListView) findViewById(R.id.listViewArtists2);
artistList2 = new ArrayList<>();
//onclick listener to the button - calls the method add artist
buttonAdd2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view){
addArtist2();
}});
}
@Override
protected void onStart() { //overriding on start method
super.onStart();
databaseArtists2.addValueEventListener(new ValueEventListener() { //database reference object attached to the value event listener, passing a new value event listener
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) { //when anything changed in the db
artistList2.clear(); //clears artist list
for(DataSnapshot artistSnapshot : dataSnapshot.getChildren()) { //everything that is contained within db reference object will be displayed in the snapshot
// Artist artist2 = artistSnapshot.getValue(Artist2.class); //gets all values of the artist class for the snapshot
Artist2 artist2 = artistSnapshot.getValue(Artist2.class);
//artistList2.add(artist2);
artistList2.add(artist2);
}
// ArtistList2 adapter2 = new ArtistList(WishListActivity.this, artistList2);
ArtistList2 adapter2 = new ArtistList2(WishListActivity.this, artistList2);
listViewArtists2.setAdapter(adapter2); //this method is executed when new information is added to the database
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) { //when anything removed in the db
}
});
}
//Add artist method
private void addArtist2() {
String name = editTextName2.getText().toString().trim();
String genre = spinnerGenres2.getSelectedItem().toString();
//checks to see if the name field is left empty
if(!TextUtils.isEmpty(name)) { //if name field isnt empty, the information will be stored in firebase
//using the post method to store values within
String id = databaseArtists2.push().getKey();
//Create new artist
Artist artist2 = new Artist(id,name,genre);
//Use set value method to store the artist within the unique generated id value
databaseArtists2.child(id).setValue(artist2);
//Prompts the user that the information has been added
Toast.makeText(this, "Book added to Wishlist", Toast.LENGTH_LONG).show();
}else{ //if the name field is empty, the user will be prompted to enter in a name
Toast.makeText(this, "Enter Book Info",Toast.LENGTH_LONG).show();
}
}}