如何在“主要活动”中调用myCustomAdapter的公开身份？

Question

I have MainActivity and Adapter. When new instance of the adapter is created I create new realm. How can I close the realm in onDestroy methood? Heres what i tryed:
MainActivity's onCreate:

public class MainActivity extends AppCompatActivity {
private ExpandableListView myELV;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    final android.support.v7.app.ActionBar actionBar = this.getSupportActionBar();
    myELV = findViewById(R.id.expandable_list_view);
    myAdapter adapter = new myAdapter(getApplicationContext());
    myELV.setAdapter(adapter);

The adapter:

public class myAdapter extends BaseExpandableListAdapter{
private Context context;
private Realm realm;


public myAdapter(Context context){
    this.context = context;
}
public void closeRealm(){
    realm.deleteAll();
    realm.close();
}

MainActivity's onDestroy:

    @Override
protected void onDestroy() {
    super.onDestroy();
    ExpandableListAdapter adapter = myELV.getExpandableListAdapter();
    adapter.closeRealm();
}    

But closeRealm() is unaccessable even tho it is public. And I want to know why?

Answer 1

Echoing, @EpicPandaForce's answer, ExpandableListAdapter is the interface type. Your closeRealm() method isn't one of the methods in that interface. One thing you could do to fix this is create aa new interface that extends ExpandableListAdapter, and lists the signatures for the new public methods you want there. Then any class that implements your new interface can be swapped for any other class that implements your new interface.

Answer 2

Yes, using @EpicPandaForce's answer, I will post the change in the code if somebody is wondering in future:

    @Override
protected void onDestroy() {
    super.onDestroy();
    myAdapter adapter =  (myAdapter) myELV.getExpandableListAdapter();
    adapter.closeRealm();
}