Java刪除樹形數據

/**
 * 刪除某個項目
 * 同時刪除下面的子項目
 *
 * @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);
}

/**
 * 遞歸獲取
 * @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);

    //遍歷二級分類的對象，把二級分類的id加入到要刪除的集合中
    for (Project project : projectList) {
        String id = project.getpId();
        ids.add(id);
        this.getIds(ids, id);
    }

}