<dependency>
    <groupId>com.jfinal</groupId>
    <artifactId>jfinal</artifactId>
    <version>4.9.15</version>
</dependency>

@Before(BlogInterceptor.class)
public class BlogController extends Controller {

    @Inject
    BlogService service;

    public void index() {
        set("blogPage", service.paginate(getParaToInt(0, 1), 10));
        render("blog.html");
    }

    public void add() {
    }

    @Before(BlogValidator.class)
    public void save() {
        getModel(Blog.class).save();
        redirect("/blog");
    }

    public void edit() {
        set("blog", service.findById(getParaToInt()));
    }

    @Before(BlogValidator.class)
    public void update() {
        getModel(Blog.class).update();
        redirect("/blog");
    }

    public void delete() {
        service.deleteById(getParaToInt());
        redirect("/blog");
    }
}

public class BlogService {

    private Blog dao = new Blog().dao();
    
    public Page<Blog> paginate(int pageNumber, int pageSize) {
        return dao.paginate(pageNumber, pageSize, "select *", "from blog order by id asc");
    }
    
    public Blog findById(int id) {
        return dao.findById(id);
    }
    
    public void deleteById(int id) {
        dao.deleteById(id);
    }
}

public class Blog extends Model<Blog> {
    
}

public class BlogValidator extends Validator {
    protected void validate(Controller controller) {
        validateRequiredString("blog.title", "titleMsg", "请输入Blog标题!");
        validateRequiredString("blog.content", "contentMsg", "请输入Blog内容!");
    }

    protected void handleError(Controller controller) {
        controller.keepModel(Blog.class);
    }
}

public class BlogInterceptor implements Interceptor {
    public void intercept(Invocation inv) {
        System.out.println("Before invoking " + inv.getActionKey());
        inv.invoke();
        System.out.println("After invoking " + inv.getActionKey());
    }
}