一段内存分页代码

public static Page<SysTreeNode> findChildrenByNodeIdPage(Integer page, Integer limit , int parentId){        if(page == null){            page = 1;//页数        }        if(limit == null){            limit = 4;//一页包含多少条内容        }        try{            //拿出所有放在listli?           List<SysTreeNode> list = ServiceManager.sysTreeNodeService.getChildrenDesc(parentId) ;            //新建返回的list            List<SysTreeNode> returnList = new ArrayList<SysTreeNode>();            //拿出总大小            int totalCount = list.size();            //内存分页            for(int i = (page - 1) * limit ;i< totalCount && i<page * limit;i++){                returnList.add(list.get(i));            }            return new Page(page, limit, list.size(), returnList);        }catch (Exception ex){            log.error("",ex);            return null;        }    }

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