Java删除树形数据

/**
 * 删除某个项目
 * 同时删除下面的子项目
 *
 * @param pId
 */
@Override
@Transactional(rollbackFor = Exception.class)
public void deleteProject(String pId) {
    ArrayList<String> pIdList = new ArrayList<>();
    pIdList.add(pId);
    this.getIds(pIdList, pId);
    projectMapper.deleteBatchIds(pIdList);
}

/**
 * 递归获取
 * @param ids
 * @param oneId
 */
private void getIds(ArrayList<String> ids, String oneId) {
    QueryWrapper<Project> wrapper = new QueryWrapper<>();
    wrapper.eq("P_PARENT_ID", oneId);
    List<Project> projectList = projectMapper.selectList(wrapper);

    //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
    for (Project project : projectList) {
        String id = project.getpId();
        ids.add(id);
        this.getIds(ids, id);
    }

}