JAVA - 返回接口列表

Question

我有这个问题,我想只在if块之后返回一个接口和实现类的列表.

public interface Lotto { }

public class LottoImplSecond implements Lotto { }
public class LottoImplFirst implements Lotto { }

public class MyClass {
   public List<Lotto> getLotto(Integer number){
       if(number==1) List<Lotto> listaLotto=new ArrayList<LottoImplFirst>();
       else if(number==2) List<Lotto> listaLotto=new ArrayList<LottoImplSecond>();
   return listaLotto;
}

Answer 1

public interface Lotto { }

public class LottoImplSecond implements Lotto { }
public class LottoImplFirst implements Lotto { }

public class MyClass {
   public List<? extends Lotto> getLotto(Integer number){
       List<? extends Lotto> listaLotto;
       if(number==1) listaLotto=new ArrayList<LottoImplFirst>();
       else if(numeber==1) listaLotto=new ArrayList<LottoImplSecond>();
       return listaLotto;
    }
}