递归用例

private void createReplyTree(List<CommentReplyVo> commentReplyVoList, List<CommentReply> replyList) {
      if (org.apache.commons.collections.CollectionUtils.isNotEmpty(replyList)) 
      {
               List<CommentReply> leftReplyList = new LinkedList<CommentReply>();
               leftReplyList.addAll(replyList);

           for (CommentReply reply : replyList)
           {
                CommentReplyVo replyVo = transform(reply);
               if (reply.getParentReplyId() == null)
               {//parentReplyId为NULL，则表示是对评论的回复
                  commentReplyVoList.add(replyVo);
                   leftReplyList.remove(reply);
               }
            }

            addReplyTreeNode(commentReplyVoList, leftReplyList);
      }
}

private void sortReplyTree(List<CommentReplyVo> commentReplyVoList, List<CommentReply> replyList) {
         if (org.apache.commons.collections.CollectionUtils.isNotEmpty(replyList)) 
          {
                List<CommentReply> leftReplyList = new LinkedList<CommentReply>();
                leftReplyList.addAll(replyList);

                for (CommentReply reply : replyList) 
                {
                      CommentReplyVo replyVo = transform(reply);
                      if (reply.getParentReplyId() == null) 
                      {//parentReplyId为NULL，则表示是对评论的回复
                             commentReplyVoList.add(replyVo);
                             leftReplyList.remove(reply);
                      }
                 }

                  addReplyTreeNode(commentReplyVoList, leftReplyList);
          }
}

private void addReplyTreeNode(List<CommentReplyVo> replyVoList, List<CommentReply> replyList) {
        if (org.apache.commons.collections.CollectionUtils.isNotEmpty(replyVoList) && org.apache.commons.collections.CollectionUtils.isNotEmpty(replyList))
        {

                List<CommentReply> leftReplyNodeList = new LinkedList<CommentReply>();
                leftReplyNodeList.addAll(replyList);

                for (CommentReplyVo replyVo : replyVoList) 
                {
                       for (CommentReply reply : replyList) 
                       {
                             if (reply.getParentReplyId() != null && reply.getParentReplyId().equals(replyVo.getId())) 
                             {
                                      replyVo.getCommentReplyVos().add(transform(reply));
                                      leftReplyNodeList.remove(reply);
                             }
                       }
                 }

                 for (CommentReplyVo replyVo : replyVoList) 
                {
                        addReplyTreeNode(replyVo.getCommentReplyVos(), leftReplyNodeList);//递归调用
                }
        }
}