Springboot个人博客系统 6 分类管理

分类管理

1.Service层

首先编写Service类
具体需求:
插入数据：saveType()
根据id获取分类：getType()
获取全部分类信息：listType()
编辑分类信息：updateType()
删除分类：deleteType()
根据分类名获取分类：getTypeByName()

TypeService接口:

public interface TypeService {
    Type saveType(Type type);

    Type getType(Long id);

    Page<Type> listType(Pageable pageable);

    Type updateType(Long id, Type type);

    void deleteType(Long id);

    Type getTypeByName(String name);
}

TypeService实现类:

@Service
public class TypeServiceImpl implements TypeService {
    @Autowired
    private TypeRepository typeRepository;
    @Transactional
    @Override
    public Type saveType(Type type) {
        return typeRepository.save(type);
    }
    @Transactional
    @Override
    public Type getType(Long id) {
        return typeRepository.findOne(id);
    }
    @Transactional
    @Override
    public Page<Type> listType(Pageable pageable) {
        return typeRepository.findAll(pageable);
    }
    @Transactional
    @Override
    public Type updateType(Long id, Type type) {
        Type t = typeRepository.findOne(id);
        if(t == null){
            throw new NotFoundException("不存在该类型");
        }
        BeanUtils.copyProperties(type, t);
        return typeRepository.save(t);
    }
    @Transactional
    @Override
    public void deleteType(Long id) {
        typeRepository.delete(id);
    }

    @Override
    public Type getTypeByName(String name) {
        return typeRepository.findByName(name);
    }
}

2.Dao层

继承JpaRepository<>类
代码如下:

public interface TypeRepository extends JpaRepository<Type,Long> {
    Type findByName(String name);
}

3.Web层

页面:

所以需要有编辑页面，新增页面，删除页面，并且能够实现分页
在这里分页使用@PageableDefault注解，设置排序依据为{id},按倒序排列
代码如下:

@Controller
@RequestMapping("/admin")
public class TypeController {
    @Autowired
    private TypeService typeService;
    @GetMapping("/types")
    public String types(@PageableDefault(size = 3,sort = {"id"},direction = Sort.Direction.DESC)
                                    Pageable pageable, Model model){
        model.addAttribute("page",typeService.listType(pageable));
        return "admin/types";
    }
    @GetMapping("/types/input")
    public String input(Model model){
        model.addAttribute("type", new Type());
        return "admin/types-input";
    }
    @GetMapping("types/{id}/input")
    public String editInput(@PathVariable Long id, Model model){
        model.addAttribute("type", typeService.getType(id));
        return "admin/types-input";

    }
    @PostMapping("/types")
    public String post(@Valid Type type, BindingResult bindingResult, RedirectAttributes attributes){
        Type type1 = typeService.getTypeByName(type.getName());
        if(type1 != null){
            bindingResult.rejectValue("name", "nameError", "不能添加重复分类");
        }
        if(bindingResult.hasErrors())return "admin/types-input";
        Type t = typeService.saveType(type);
        if(t == null){
            attributes.addFlashAttribute("message", "新增失败");
        }else {
            attributes.addFlashAttribute("message", "新增成功");
        }
        return "redirect:/admin/types";
    }
    @PostMapping("/types/{id}")
    public String editPost(@Valid Type type, BindingResult bindingResult,@PathVariable Long id, RedirectAttributes attributes){
        Type type1 = typeService.getTypeByName(type.getName());
        if(type1 != null){
            bindingResult.rejectValue("name", "nameError", "不能添加重复分类");
        }
        if(bindingResult.hasErrors())return "admin/types-input";
        Type t = typeService.updateType(id,type);
        if(t == null){
            attributes.addFlashAttribute("message", "更新失败");
        }else {
            attributes.addFlashAttribute("message", "更新成功");
        }
        return "redirect:/admin/types";
    }
    @GetMapping("/types/{id}/delete")
    public String delete(@PathVariable Long id, RedirectAttributes attributes){
        typeService.deleteType(id);
        attributes.addFlashAttribute("message","删除成功");
        return "redirect:/admin/types";
    }
}