cookie 实现历史浏览商品并排序
//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[i].getName().startsWith(HISTORY_PRE)) { String getnewgoodsId = cookies[i].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[i].getName().startsWith(HISTORY_PRE)) { String goodsId = cookies[i].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; }}