public List<Link> listAllLink() {
		SQLCommand cmd=new SQLCommand();
		RowSet rs=cmd.queryRowSet("select * from link");
		List<Link> list=new ArrayList<Link>();
		Link link;
		try {
			while(rs.next()){
			link=new Link();	
			link.setLId(rs.getLong("l_id"));
			link.setLAddtime(rs.getDate("l_addtime"));
			link.setLImg(rs.getString("l_img"));
			link.setLInfo(rs.getString("l_info"));
			link.setLIsLock(rs.getBoolean("l_islock"));
			link.setLName(rs.getString("l_name"));
			link.setLUrl(rs.getString("l_url"));
		
			list.add(link);
			} 
			
			 return list;
			
		} catch (SQLException e) {
			 
			e.printStackTrace();
			return null;
		} 
		
	}