public class VoteLimitFilter implements Filter {

    private FilterConfig fc = null;

    private VoterDao voterDao;

    public void doFilter(ServletRequest srequest, ServletResponse sresponse,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) srequest;
        HttpServletResponse response = (HttpServletResponse) sresponse;
        HttpSession session = request.getSession();

        String dispatch = request.getParameter("dispatch");
        String titleId =request.getParameter("titleId");
        //白名单
        List<String> whitelist = new ArrayList<String>();
        whitelist.add("insertOrUpdateTitle");
        whitelist.add("checkVoteById");
        whitelist.add("showTitleList");
        whitelist.add("prepareNew");
        whitelist.add("showVoteResult");
        whitelist.add("prepareInsertItem");
        whitelist.add("getTitleById");
        whitelist.add("getOptionById");
        whitelist.add("updateItem");
        whitelist.add("insertItem");
        whitelist.add("deleteVote");
        whitelist.add("getVoterList");
        
        
        if(!whitelist.contains(dispatch)){
            String ip = request.getRemoteAddr(); // 获取客户端IP
            int optionid = 1;
            // //获取选择的选项ID
            try {
                Date now = new Date(); // 获取当前时间
                Date last = voterDao.getLastVoteTime(ip,Integer.parseInt(titleId)); // 获取该IP的上次对该标题的投票时间
                if (last == null) { // 数据库中没有记录该IP，则该IP地址没有投过票
                    addCookie(request, response,titleId); // 在客户端的cookie中添加该用户投票记录
                    Voter voter = new Voter();
                    voter.setVote_title(Integer.parseInt(titleId));
                    voter.setVoter_Ip(ip);
                    voter.setVoter_option(optionid);
                    voter.setVote_time(StringUtil.timeTostr(now));
                    voterDao.saveVoteTime(voter); // 在数据库中记录该IP、选择的选项ID和投票时间
                    chain.doFilter(request, response);
                } else { // 该IP地址投过票，则接着判断客户端cookie中是否记录了用户投票情况（用来解决局域网中某个ip投票后，其他ip不能再进行投票的问题）
                    boolean voteincookie = seeCookie(request); // 判断当前使用该IP的用户的客户端的cookie中是否记录了投票标记
                    if (voteincookie) { // 如果记录了该用户已经投过票
                        request.setAttribute("message",
                                "● 您已经投过票了，1小时内不允许重复投票！");
                        RequestDispatcher rd = request
                                .getRequestDispatcher("fail.jsp");
                        rd.forward(request, response);
                    } else {