使用注解的方式，实现对虚拟数据表 news(id(int),title(varcha(100)),author(varchar(50)),content(text),pubdate(date)) 进行操作的三层结构，写出测试程序

注解方式的三层结构包括：实体类、数据访问层（DAO）、业务逻辑层（Service）。以下是对应的代码示例：

实体类 News：

public class News {
    private int id;
    private String title;
    private String author;
    private String content;
    private Date pubdate;

    public News() {}

    public News(int id, String title, String author, String content, Date pubdate) {
        this.id = id;
        this.title = title;
        this.author = author;
        this.content = content;
        this.pubdate = pubdate;
    }

    // getter and setter methods
}

数据访问层 NewsDAO：

public interface NewsDAO {
    @Select("SELECT * FROM news WHERE id=#{id}")
    News findById(int id);

    @Select("SELECT * FROM news ORDER BY pubdate DESC")
    List<News> findAll();

    @Insert("INSERT INTO news (title, author, content, pubdate) VALUES (#{title}, #{author}, #{content}, #{pubdate})")
    int addNews(News news);

    @Update("UPDATE news SET title=#{title}, author=#{author}, content=#{content}, pubdate=#{pubdate} WHERE id=#{id}")
    int updateNews(News news);

    @Delete("DELETE FROM news WHERE id=#{id}")
    int deleteNews(int id);
}

业务逻辑层 NewsService：

@Service
public class NewsService {
    @Autowired
    private NewsDAO newsDAO;

    public News getNewsById(int id) {
        return newsDAO.findById(id);
    }

    public List<News> getAllNews() {
        return newsDAO.findAll();
    }

    public void addNews(News news) {
        newsDAO.addNews(news);
    }

    public void updateNews(News news) {
        newsDAO.updateNews(news);
    }

    public void deleteNews(int id) {
        newsDAO.deleteNews(id);
    }
}

测试程序 NewsTest：

@RunWith(SpringRunner.class)
@SpringBootTest
public class NewsTest {
    @Autowired
    private NewsService newsService;

    @Test
    public void testCRUD() {
        // 添加新闻
        News news = new News(1, "Java 从入门到精通", "张三", "Java 是一门很好的语言", new Date());
        newsService.addNews(news);
        assertThat(news.getId()).isGreaterThan(0);

        // 查询新闻
        News savedNews = newsService.getNewsById(news.getId());
        assertThat(savedNews.getTitle()).isEqualTo("Java 从入门到精通");

        // 更新新闻
        savedNews.setTitle("Java 从入门到放弃");
        newsService.updateNews(savedNews);
        News updatedNews = newsService.getNewsById(savedNews.getId());
        assertThat(updatedNews.getTitle()).isEqualTo("Java 从入门到放弃");

        // 删除新闻
        newsService.deleteNews(updatedNews.getId());
        News deletedNews = newsService.getNewsById(updatedNews.getId());
        assertThat(deletedNews).isNull();
    }
}

以上代码示例使用了 Spring Boot 和 MyBatis 框架，可根据实际情况进行调整。