Springboot个人博客系统 7 博客管理

    @Data
    @NoArgsConstructor
    public class BlogQuery {
    private String title;
    private Long typeId;
    private boolean recommend;
    }

    @Service
    public class BlogServiceImpl implements BlogService {
    @Autowired
    private BlogRepository blogRepository;
    
    @Override
    public Blog getBlog(Long id) {
        return blogRepository.findOne(id);
    }
    
    @Override
    public Page<Blog> listBlog(Pageable pageable, BlogQuery blog) {
        return blogRepository.findAll(new Specification<Blog>() {
            @Override
            public Predicate toPredicate(Root<Blog> root, CriteriaQuery<?> cq, CriteriaBuilder cb) {
                List<Predicate> predicates = new ArrayList<>();
                if(!"".equals(blog.getTitle()) && blog.getTitle() != null){
                    predicates.add(cb.like(root.<String>get("title"),"%"+blog.getTitle()+"%"));
                }
                if(blog.getTypeId() != null){
                    predicates.add(cb.equal(root.<Type>get("type").get("id"),blog.getTypeId()));
                }
                if(blog.isRecommend()){
                    predicates.add(cb.equal(root.<Boolean>get("recommend"), blog.isRecommend())) ;
                }
                cq.where(predicates.toArray(new Predicate[predicates.size()]));
                return null;
            }
        },pageable);
    }
    @Transactional
    @Override
    public Blog saveBlog(Blog blog) {
        if(blog.getId() == null){
            blog.setCreateTime(new Date());
            blog.setUpdateTime(new Date());
            blog.setViews(0);
        }else {
            blog.setUpdateTime(new Date());
        }
    
        return blogRepository.save(blog);
    }
    
    @Override
    public Blog updateBlog(Long id, Blog blog) {
        Blog b = blogRepository.findOne(id);
        if (b == null){
            throw new NotFoundException("该博客不存在");
        }
        BeanUtils.copyProperties(b,blog);
        return blogRepository.save(b);
    }
    
    @Override
    public void deleteBlog(Long id) {
        blogRepository.delete(id);
    }
    }

    public interface BlogService {
    
    Blog getBlog(Long id);
    
    Page<Blog> listBlog(Pageable pageable, BlogQuery blog);
    
    Blog saveBlog(Blog blog);
    
    Blog updateBlog(Long id, Blog blog);
    
    void deleteBlog(Long id);
    
    }

    public interface BlogRepository extends JpaRepository<Blog, Long>, JpaSpecificationExecutor<Blog> {
    }

    public class BlogController {
    private static final String INPUT = "admin/blogs-input";
    private static final String LIST = "admin/blogs";
    private static final String REDIRECT_LIST = "redirect:/admin/blogs";
    @Autowired
    private BlogService blogService;
    @Autowired
    private TypeService typeService;
    @Autowired
    private TagService tagService;
    
    /** * 博客列表
     * 分页查询，一页为十条数据
     * 采取DESC排序（倒序）
     * @param pageable
     * @param model
     * @param blog
     * @return
     */
    @GetMapping("/blogs")
    public String list(@PageableDefault(size = 10, sort = {"updateTime"}, direction = Sort.Direction.DESC) Pageable pageable, Model model, BlogQuery blog){
        model.addAttribute("types", typeService.listType());
        model.addAttribute("page", blogService.listBlog(pageable,blog));
        return LIST;
    }
    
    /** * 博客查询
     * 使用了AJAX技术，只更新一部分页面
     * @param pageable
     * @param model
     * @param blog
     * @return
     */
    @PostMapping("/blogs/search")
    public String search(@PageableDefault(size = 10, sort = {"updateTime"}, direction = Sort.Direction.DESC) Pageable pageable, Model model, BlogQuery blog){
        model.addAttribute("page", blogService.listBlog(pageable,blog));
        return "admin/blogs :: blogList";
    }
    
    /** * 博客编辑
     * 从前端页面得到一个id
     * 通过id得到这个博客并将对象传到前端
     * @param id
     * @param model
     * @return
     */
    @GetMapping("/blogs/{id}/input")
    public String editinput(@PathVariable Long id, Model model){
        setTypeAndTag(model);
        Blog b = blogService.getBlog(id);
        b.init();
        model.addAttribute("blog", b);
        return INPUT;
    }
    
    /** * 查询所有博客标签和分类
     * @param model
     */
    private void setTypeAndTag(Model model){
        model.addAttribute("types", typeService.listType());
        model.addAttribute("tags", tagService.listTag());
    }
    
    /** * 博客新增
     * new一个空对象传到前端，并将所有标签，分类信息传到前端进行显示
     * 空对象是因为新增与编辑共用页面，为了防止报错传过去一个空对象
     * @param model
     * @return
     */
    @GetMapping("/blogs/input")
    public String input(Model model){
        setTypeAndTag(model);
        model.addAttribute("blog", new Blog());
        return INPUT;
    }
    
    /** * 处理post表单
     * 首先得到session中的用户信息，设置为作者
     * 校验传过来的标签分类是否和数据库一直，设置标签分类
     * 若前端传过来的id为空，则说明是新增，使用saveBlog
     * 若id不为空，则说明是更新，使用updateBlog
     * @param blog
     * @param session
     * @param attributes
     * @return
     */
    @PostMapping("/blogs")
    public String post(Blog blog, HttpSession session, RedirectAttributes attributes){
        String flag = blog.getFlag();
        System.out.println(flag);
        blog.setUser((User)session.getAttribute("user"));
        blog.setType(typeService.getType(blog.getType().getId()));
        blog.setTags(tagService.listTag(blog.getTagIds()));
        Blog b;
        if(blog.getId() == null){
            b = blogService.saveBlog(blog);
        }else {
            b = blogService.updateBlog(blog.getId(), blog);
        }
    
        if(b == null){
            attributes.addFlashAttribute("message","操作失败");
        }else {
            attributes.addFlashAttribute("message","操作成功");
        }
        return  REDIRECT_LIST;
    }
    
    /** * 根据前端传过来的id进行删除操作
     * @param id
     * @param attributes
     * @return
     */
    @GetMapping("/blogs/{id}/delete")
    public String delete(@PathVariable Long id, RedirectAttributes attributes){
        blogService.deleteBlog(id);
        attributes.addFlashAttribute("message","删除成功");
        return  REDIRECT_LIST;
    }
    
    
    }