递归删除树节点

public int delete(Long id) {
        //删除权限的集合ids
        List<Long> ids = new ArrayList<>();
        ids.add(id);
        //递归的将一级分类下的id也加入到集合中
        this.getIds(ids,id);
        SmsPermissionExample example = new SmsPermissionExample();
        example.createCriteria().andIdIn(ids);
        return smsPermissionMapper.deleteByExample(example);
    }
    //递归获取所有的节点
    private void getIds(List<Long> ids, Long id) {
        SmsPermissionExample example = new SmsPermissionExample();
        example.createCriteria().andPidEqualTo(id);
        List<SmsPermission> smsPermissions = smsPermissionMapper.selectByExample(example);
        //遍历二级分类的对象，把二级分类的id加入到要删除的集合中
        if(smsPermissions.size()>0){
            for (SmsPermission permission : smsPermissions) {
                Long permissionId = permission.getId();
                ids.add(permissionId);
                //把二级分类的每一个ID，查询它下面的子节点
                this.getIds(ids,permissionId);
            }
        }
    }