如何利用Java开发CMS系统的文章发布功能

@Entity
@Table(name = "article")
public class Article {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String title;
    
    @Lob
    private String content;
    
    private String author;
    
    @Column(name = "publish_date")
    private Date publishDate;
    
    @ManyToOne
    @JoinColumn(name = "category_id")
    private Category category;

    // getters and setters
}

@Entity
@Table(name = "category")
public class Category {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String name;

    // getters and setters
}

@Repository
public class ArticleDAO {
    @Autowired
    private EntityManager entityManager;
    
    public void save(Article article) {
        entityManager.persist(article);
    }
    
    public void update(Article article) {
        entityManager.merge(article);
    }
    
    public void delete(Article article) {
        entityManager.remove(article);
    }
    
    public Article findById(Long id) {
        return entityManager.find(Article.class, id);
    }
    
    // 其他数据库操作方法
}

@Service
@Transactional
public class ArticleService {
    @Autowired
    private ArticleDAO articleDAO;
    
    public void saveArticle(Article article) {
        articleDAO.save(article);
    }
    
    public void updateArticle(Article article) {
        articleDAO.update(article);
    }
    
    public void deleteArticle(Article article) {
        articleDAO.delete(article);
    }
    
    public Article findArticleById(Long id) {
        return articleDAO.findById(id);
    }
    
    // 其他服务方法
}