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标题: 添加到cookie中数据有没有排序规则 [打印本页]

作者: 记忆 时间: 2013-1-11 10:38
标题: 添加到cookie中数据有没有排序规则
在向cookie插入数据，那么cookie中的数据读取出来的顺序怎么和插入的数据顺序不一样啊，你看我之前插入的数据顺序

见附件)；那cookie中数据的排序是不是有一种规则啊

作者: 站长苏飞 时间: 2013-1-11 10:47
这个应该不影响你开发吧

作者: 记忆 时间: 2013-1-11 10:53

admin 发表于 2013-1-11 10:47
这个应该不影响你开发吧

如果我用cookie来存储浏览过的商品，读取cookie中的数据是不是应该和浏览的顺序一样啊，应为我可能只读出cookie中前5条数据

作者: 站长苏飞 时间: 2013-1-11 11:29
这个你可以选择自己读取后排序，或者存储Json数据
你说的这个有例子如下：
[code=csharp]

//商品历史浏览记录

public class HistoryCookieUtil {

private final static String HISTORY_PRE  = "history_"; //Cookie中，历史浏览
private final static String HISTORY_PATH = "/";  //Cookie中，历史浏览的Cookie的路径

//清除所有历史浏览记录
public static void removeAllHistoryCookie(HttpServletRequest request,HttpServletResponse response) {
      Cookie[] cookies = request.getCookies();
      if (null == cookies || cookies.length == 0) {
         return;
      }
      for (Cookie thisCookie : cookies) {
         if (thisCookie.getName().startsWith(HISTORY_PRE)) {
            thisCookie.setMaxAge(0); // 删除这个cookie
            thisCookie.setPath(HISTORY_PATH);
            response.addCookie(thisCookie);
         }
      }
}

//清除单个商品的浏览记录
public static void removeHistoryCookie(HttpServletRequest request,HttpServletResponse response, Long goodsId) {
      if (goodsId == null) {
         return;
      }
      Cookie[] cookies = request.getCookies();
      if (null == cookies || cookies.length == 0) {
         return;
      }
      for (Cookie thisCookie : cookies) {
         if (thisCookie.getName().equals(HISTORY_PRE + goodsId)) {
            thisCookie.setMaxAge(0); // 删除这个cookie
            thisCookie.setPath(HISTORY_PATH);
            response.addCookie(thisCookie);
         }
      }
}

//加入单个商品浏览记录到cookie(有效期30天)
public static void setHistoryCookie(HttpServletRequest request,HttpServletResponse response, Long goodsId) {
      if (goodsId == null) {
         return;
      }
      String nameString = HISTORY_PRE + goodsId.toString();
      Cookie cookie = new Cookie(nameString, goodsId.toString());
      cookie.setPath(HISTORY_PATH);
      cookie.setMaxAge(3600 * 24 * 30); // 30 days
      response.addCookie(cookie);
}


public static void addHistoryCookie(HttpServletRequest request,HttpServletResponse response,ServletContext servletContext, Long goodsId) {
      if (goodsId == null ) {
         return;
      }
      Integer viewNum = 10;//页面商品显示的个数（默认显示10）
      String thetype = EnumBoardName.toMap().get("browse_history");//汉字表示
      BoardDao boardDao = (BoardDao) getBean(servletContext, "boardDao");
      Board board = boardDao.getBoardByName(thetype);
      if(null != board && null != board.getAmount()){
      viewNum = board.getAmount();
      }
      String nameString = HISTORY_PRE + goodsId.toString();
      Cookie[] cookies = request.getCookies();
      int historyCookieNum = 0;//历史浏览的当前 cookie 数目
      if (null != cookies && cookies.length > 0) {
         for (Cookie thisCookie : cookies) {
            if (thisCookie.getName().startsWith(HISTORY_PRE)) {
               historyCookieNum++;
            }
         }
      }
      if(historyCookieNum<viewNum){//小于显示数目时候
      String flagexist ="no";//标记cookie中是否存在相同的历史浏览商品
         for (Cookie thisCookie : cookies) {
            if (thisCookie.getName().equalsIgnoreCase(nameString)) {//如果有相同的记录先移去再加上
               removeHistoryCookie(request, response, goodsId);
               setHistoryCookie(request, response, goodsId);
               flagexist ="yes";
                  break;
            }
         }
         if(flagexist.equals("no")){//cookie中不存在则直接加入cookie
         setHistoryCookie(request, response, goodsId);
         }
      }
      if(historyCookieNum == viewNum){//等于显示数目的时候移去最旧一个记录加入新的记录
      List<String> list = new ArrayList<String>();//存放当前的历史cookie
         for (Cookie thisCookie : cookies) {
            if (thisCookie.getName().startsWith(HISTORY_PRE)) {//
               String oldGoodsId = thisCookie.getValue();//
               list.add(oldGoodsId);
            }
         }
         if(list.contains(goodsId.toString())){//判断（防止详情页面不断刷新调用addcookie方法）
         removeHistoryCookie(request, response, goodsId);
         setHistoryCookie(request, response, goodsId);
         }else{
            for (Cookie thisCookie : cookies) {
                  if (thisCookie.getName().startsWith(HISTORY_PRE)) {//去掉第一条旧的历史记录
                  String oldGoodsId = thisCookie.getValue();//旧的商品ID
                  removeHistoryCookie(request, response, Long.valueOf(oldGoodsId));
                  setHistoryCookie(request, response, goodsId);
                     break;
                  }
            }
         }
      }
      if(historyCookieNum > viewNum){//考虑后台重新设置历史显示数目变小后的情况，历史cookie中存在的数目大于设置显示的数目后要重新获取前viewNum条历史记录
      removeAllHistoryCookie(request, response);//先移除所有历史浏览记录
      int addNewNum = 0 ;
         for (int i=cookies.length-1;i>0;i-- ) {
            if(viewNum == addNewNum){//获取到设置数目的记录后跳出
               break;
            }
            if (cookies.getName().startsWith(HISTORY_PRE)) {
               String getnewgoodsId = cookies.getValue();
               if(null != getnewgoodsId && getnewgoodsId.length()>0){
               setHistoryCookie(request, response, Long.valueOf(getnewgoodsId));
               addNewNum++ ;
               }
            }
         }
      }

}

public static List<RankGoods> getHistoryRankList(HttpServletRequest request,ServletContext servletContext) {
      List<RankGoods> list = new ArrayList<RankGoods>();
      Cookie[] cookies = request.getCookies();
      if (null == cookies || cookies.length < 1) {
         return null;
      }
      String thetype = EnumBoardName.toMap().get("browse_history");//汉字表示
      String rankTitle = "历史浏览";//榜行标题
      Integer viewlistNum = 10;//页面商品显示的个数（默认显示10）
      BoardDao boardDao = (BoardDao) getBean(servletContext, "boardDao");
      Board board = boardDao.getBoardByName(thetype);
      if(null != board && null != board.getAmount()){
         viewlistNum = board.getAmount();
      rankTitle = board.getTitle();
      }
      GoodsDao goodsDao = (GoodsDao) getBean(servletContext, "goodsDao");
      int viewHistoryNum = 0 ;
      for (int i=cookies.length-1;i>0;i-- ) {//倒序排列
      if(viewlistNum == viewHistoryNum){//等于后台设置显示数目时不在显示
      break;
      }
         if (cookies.getName().startsWith(HISTORY_PRE)) {
            String goodsId = cookies.getValue();
            if (goodsId == null || goodsId.trim().length()<1) {
                  continue;
            }
            Long goodsId2 = Long.valueOf(goodsId);
            Goods goods = new Goods();
   try {
      goods = goodsDao.getGoods(goodsId2);
   } catch (Exception e) {
      e.printStackTrace();
   }
            RankGoods hgs = new RankGoods();
            hgs.setGoodsId(String.valueOf(goods.getId()));//商品Id
            ............;
            list.add(hgs);
            viewHistoryNum ++ ;
         }
      }
      return list;
}

}
[/code]

作者: 记忆 时间: 2013-1-11 14:58

admin 发表于 2013-1-11 11:29
这个你可以选择自己读取后排序，或者存储Json数据
你说的这个有例子如下：

谢谢

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