springboot-以树形结构获取所有商品分类

    @ApiOperation("以树形结构获取所有商品分类")
    @RequestMapping(value = "/categoryTreeList", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult> categoryTreeList() {
        List list = portalProductService.categoryTreeList();
        return CommonResult.success(list);
    }

    
    List categoryTreeList();
    
    @Override
    public List categoryTreeList() {
        PmsProductCategoryExample example = new PmsProductCategoryExample();
        List allList = productCategoryMapper.selectByExample(example);
        List result = allList.stream()
                .filter(item -> item.getParentId().equals(0L))
                .map(item -> covert(item, allList)).collect(Collectors.toList());
        return result;
    }

    
    private PmsProductCategoryNode covert(PmsProductCategory item, List allList) {
        PmsProductCategoryNode node = new PmsProductCategoryNode();
        BeanUtils.copyProperties(item, node);
        List children = allList.stream()
                .filter(subItem -> subItem.getParentId().equals(item.getId()))
                .map(subItem -> covert(subItem, allList)).collect(Collectors.toList());
        node.setChildren(children);
        return node;
    }

    List selectByExample(PmsProductCategoryExample example);