《黑马旅游网》综合案例十旅游线路收藏

1.旅游线路收藏功能
　　　分析
　　判断当前登录用户是否收藏过该线路

当页面加载完成后，发送ajax请求，获取用户是否收藏的标记

根据标记，展示不同的按钮样式

public 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);
}

@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
}

@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;
}

$(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
        }
    });

//设置收藏次数
$("#favoriteCount").html("已收藏"+route.count+"次");

//4. 查询收藏次数
int count = favoriteDao.findCountByRid(route.getRid());
route.setCount(count);

@Override
public int findCountByRid(int rid) {
    String sql = "SELECT COUNT(*) FROM tab_favorite WHERE rid = ?";

    return template.queryForObject(sql,Integer.class,rid);
}

1.点击按钮收藏线路

编码
前台代码
    $(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";
       }
    })
}

后台代码
RouteServlet
public void addFavorite(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //1. 获取线路rid
    String rid = request.getParameter("rid");
    //2. 获取当前登录的用户
    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);
}