"Dark Horse Travel Network" Comprehensive Case Day04
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Tourist route collection function
14.1 Analysis
14.1.1 Determine whether the currently logged-in user has bookmarked the lineWhen the page is loaded, send an ajax request to get the mark of whether the user is favorite
According to the mark, display different button styles
14.2 Writing code
14.2.1 Background code
RouteServletpublic void isFavorite(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1. 获取线路id String rid = request.getParameter("rid"); //2. 获取当前登录的用户 user User user = (User) request.getSession().getAttribute("user"); int uid;//用户id if(user == null){ //用户尚未登录 uid = 0; }else{ //用户已经登录 uid = user.getUid(); } //3. 调用FavoriteService查询是否收藏 boolean flag = favoriteService.isFavorite(rid, uid); //4. 写回客户端 writeValue(flag,response); }FavoriteService@Override public boolean isFavorite(String rid, int uid) { Favorite favorite = favoriteDao.findByRidAndUid(Integer.parseInt(rid), uid); return favorite != null;//如果对象有值，则为true，反之，则为false }FavoriteDao@Override public Favorite findByRidAndUid(int rid, int uid) { Favorite favorite = null; try { String sql = " select * from tab_favorite where rid = ? and uid = ?"; favorite = template.queryForObject(sql, new BeanPropertyRowMapper<Favorite>(Favorite.class), rid, uid); } catch (DataAccessException e) { e.printStackTrace(); } return favorite; }14.2.2 Front Desk Code
route_detail.html$(function () { //发送请求，判断用户是否收藏过该线路 var rid = getParameter("rid"); $.get("route/isFavorite",{ rid:rid},function (flag) { if(flag){ //用户已经收藏过 //<a class="btn already" disabled="disabled"> //设置收藏按钮的样式 $("#favorite").addClass("already"); $("#favorite").prop("disabled",disabled); }else{ //用户没有收藏 } }); });14.3 Dynamic display of favorites
Front desk:
//设置收藏次数 $("#favoriteCount").html("已收藏"+route.count+"次");Backstage:
RouteService@Override public Route findOne(String rid) { //1.根据id去route表中查询route对象 Route route = routeDao.findOne(Integer.parseInt(rid)); //2.根据route的id查询图片集合信息 List<RouteImg> routeImgList = routeImgDao.findByRid(route.getRid()); //2.2将集合设置到route对象 route.setRouteImgList(routeImgList); //3.根据route的sid(商家id)查询商家对象 Seller seller = sellerDao.findById(route.getSid()); route.setSeller(seller); //4.查询收藏次数 int count = favoriteDao.findCountByRid(route.getRid()); route.setCount(count); return route; }FavoriteDao@Override public int findCountByRid(int rid) { String sql = "SELECT COUNT(*) FROM tab_favorite WHERE rid = ?"; return template.queryForObject(sql,Integer.class,rid); }14.4 Click the button to bookmark the line
14.4.1 Analysis:
14.4.2 Encoding
Front desk code
$(function () { // 发送请求，判断用户是否收藏过该线路 var rid = getParameter("rid"); $.get("route/isFavorite",{ rid:rid},function (flag) { if(flag){ // 用户已经收藏过 //<a class="btn already" disabled="disabled"> //设置收藏按钮的样式 $("#favorite").addClass("already"); $("#favorite").attr("disabled","disabled"); //删除按钮的点击事件 $("#favorite").removeAttr("onclick"); }else{ // 用户没有收藏 } }); }); //点击收藏按钮触发的方法 function addFavorite(){ var rid = getParameter("rid"); //1. 判断用户是否登录 $.get("user/findOne",{ },function (user) { if(user){ //用户登录了 //添加功能 $.get("route/addFavorite",{ rid:rid},function () { //代码刷新页面 location.reload(); }); }else{ //用户没有登录 alert("您尚未登录，请登录"); location.href="http://localhost/travel/login.html"; } }) }Code behind
RouteServlet/** * 添加收藏 * @param request * @param response * @throws IOException */ public void addFavorite(HttpServletRequest request, HttpServletResponse response) throws IOException { //1.获取线路rid String rid = request.getParameter("rid"); //2.获取当前登录用户 User user = (User) request.getSession().getAttribute("user"); int uid;//用户id if(user == null){ //用户尚未登录 return ; }else{ //用户已经登录 uid = user.getUid(); } //3.调用service添加 favoriteService.add(rid, uid); }FavoriteService@Override public void add(String rid, int uid) { favoriteDao.add(Integer.parseInt(rid),uid); }FavoriteDao@Override public void add(int rid, int uid) { String sql = "insert into tab_favorite values(?,?,?)"; template.update(sql,rid,new Date(),uid); }