How to Convert List to List<Object>

Answer 1

model.class

public class Model {

private List stringList = new ArrayList<>();

public List getStringList() {
    return stringList;
}

public void setStringList(List stringList) {
    this.stringList = stringList;
}

}

MainActivity

public class MainActivity extends AppCompatActivity {

Model model = new Model();
Spinner spinner;

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

    spinner=findViewById(R.id.spinner);

    List itemList = new ArrayList();
    itemList.add("item1");
    itemList.add("item2");
    itemList.add("item3");


   model.setStringList(itemList);


    ArrayAdapter dataAdapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, model.getStringList());
    dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner.setAdapter(dataAdapter);

}

}