将查出来的数据拼树状结构

    public List<SysMenu> getSysMenuByRoleId(Integer roleId) throws Exception {
        try {
            ArrayList<SysMenu> tempList = new ArrayList<>();
            List<SysMenu> smList = sysMenuMapper.getSysMenuByRoleId(roleId);
            for (SysMenu sysMenu : smList) {
                //判断找出父节点
                if (sysMenu.getParentId() == null) {
                    //把所有父节点保存到一起
                    tempList.add(sysMenu);
                } else {
                    //遍历所有的父节点
                    for (SysMenu menu : tempList) {
                        if (menu.getId().equals(sysMenu.getParentId())) {
                            //找出子节点对应的父节点，然后填充
                            List<SysMenu> children = menu.getChildren();
                            if (children == null)
                                children = new ArrayList<>();
                            children.add(sysMenu);
                            menu.setChildren(children);
                        }
                    }
                }
            }
            smList.sort(Comparator.comparing(SysMenu::getId));
            return smList;
        } catch (Exception e) {
            log.error("【根据RoleId获取SysMenu数据异常】异常信息为：" + e.getMessage());
            throw new Exception(e.getMessage());
        }
    }