public class Book{
private Integer id;
private String name;
private Double price;
//getter setter
}
public interface IBookManager{
public void add(Book book);
public void delete(Integer id);
public Book query(Integer id);
public void update(Book book)
}
public class BookManagerImpl implements IBookManager{
}
小伙子还是要自己学，这叫什么破问题啊