递归查询本节点的id及孩子节点的id

1、Controller:

    @RequestMapping("get_deep_category.do")
    @ResponseBody
    public ServerResponse getCategoryAndDeepChildrenCategory(HttpSession session,@RequestParam(value = "categoryId" ,defaultValue = "0") Integer categoryId){
        User user = (User)session.getAttribute(Const.CURRENT_USER);
        if(user == null){
            return ServerResponse.createByErrorCodeMessage(ResponseCode.NEED_LOGIN.getCode(),"用户未登录,请登录");
        }
        if(iUserService.checkAdminRole(user).isSuccess()){
            //查询当前节点的id和递归子节点的id
//            0->10000->100000
            return iCategoryService.selectCategoryAndChildrenById(categoryId);

        }else{
            return ServerResponse.createByErrorMessage("无权限操作,需要管理员权限");
        }
    }

2、Service:

           ServerResponse<List<Integer>> selectCategoryAndChildrenById(Integer categoryId);

3、ServiceImpl:

/**
 * 递归查询本节点的id及孩子节点的id
 * @param categoryId
 * @return
 */
public ServerResponse<List<Integer>> selectCategoryAndChildrenById(Integer categoryId){
    Set<Category> categorySet = Sets.newHashSet();
    findChildCategory(categorySet,categoryId);


    List<Integer> categoryIdList = Lists.newArrayList();
    if(categoryId != null){
        for(Category categoryItem : categorySet){
            categoryIdList.add(categoryItem.getId());
        }
    }
    return ServerResponse.createBySuccess(categoryIdList);
}


//递归算法,算出子节点
private Set<Category> findChildCategory(Set<Category> categorySet ,Integer categoryId){
    Category category = categoryMapper.selectByPrimaryKey(categoryId);
    if(category != null){
        categorySet.add(category);
    }
    //查找子节点,递归算法一定要有一个退出的条件
    List<Category> categoryList = categoryMapper.selectCategoryChildrenByParentId(categoryId);
    for(Category categoryItem : categoryList){
        findChildCategory(categorySet,categoryItem.getId());
    }
    return categorySet;
}

4、Mapper:

 ①：Category selectByPrimaryKey(Integer id);

 ②：List<Category> selectCategoryChildrenByParentId(Integer parentId);

 5、Mapper.xml:

①：

<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
  select 
  <include refid="Base_Column_List" />
  from mmall_category
  where id = #{id,jdbcType=INTEGER}
</select>

 ②：

 <select id="selectCategoryChildrenByParentId" resultMap="BaseResultMap" parameterType="int">
   select
   <include refid="Base_Column_List"/>
   from mmall_category
   where parent_id = #{parentId}
</select>

标签：category,return,递归,id,categorySet,节点,categoryId
来源： https://www.cnblogs.com/sensenh/p/16329262.html