综合案例-黑马旅游网_分类数据展示功能

分析

效果

后端代码实现

CategoryDao接口

package com.bai.dao;

import com.bai.domain.Category;

import java.util.Calendar;
import java.util.List;

public interface CategoryDao {
    /**
     * 查询所有
     * @return
     */
    public List<Category> findAll();
}

CategoryDaoImpl实现类

package com.bai.dao.impl;

import com.bai.dao.CategoryDao;
import com.bai.domain.Category;
import com.bai.util.JDBCUtils;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.List;

public class CategoryDaoImpl implements CategoryDao {

    private JdbcTemplate template=new JdbcTemplate(JDBCUtils.getDataSource());

    @Override
    public List<Category> findAll() {
        String sql="select * from tab_category";
        return template.query(sql,new BeanPropertyRowMapper<Category>(Category.class));
    }
}

categoryService接口

package com.bai.service;

import com.bai.domain.Category;

import java.util.List;

public interface categoryService {
    public List<Category> findAll();
}

categoryServiceImpl实现类

package com.bai.service.impl;

import com.bai.dao.CategoryDao;
import com.bai.dao.impl.CategoryDaoImpl;
import com.bai.domain.Category;
import com.bai.service.categoryService;

import java.util.List;

public class categoryServiceImpl implements categoryService {
    private CategoryDao categoryDao = new CategoryDaoImpl();

    @Override
    public List<Category> findAll() {
        return categoryDao.findAll();
    }
}

BaseServlet类 此类添加了两个方法

    /**
     * 直接将传入的对象序列化为json 并且写回客户端
     * @param obj
     * @param response
     * @throws IOException
     */
    public void writeValue(Object obj,HttpServletResponse response) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        response.setContentType("application/json;charset=utf-8");
        mapper.writeValue(response.getOutputStream(),obj);
    }

    /**
     * 将传入等待对象序列化为json 返回
     * @param obj
     * @return
     */
    public String writeValueAsString(Object obj) throws JsonProcessingException {
        ObjectMapper mapper = new ObjectMapper();
        return mapper.writeValueAsString(obj);
    }

CategoryServlet类

package com.bai.web.servlet;

import com.bai.domain.Category;
import com.bai.service.categoryService;
import com.bai.service.impl.categoryServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@WebServlet("/category/*")
public class CategoryServlet extends BaseServlet {
    private final categoryService service = new categoryServiceImpl();

    /**
     * 查询所有
     *
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    public void findAll(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        List<Category> sc = service.findAll();
        writeValue(sc,resp);
    }


}

 前端代码实现

hader.html加载后 发送ajax请求 请求category/findAll

<!-- 头部 start -->
<script>
    $(function () {
        //查询用户的数据
       $.get("findUserServlet",{},function (data) {
           var msg = "欢迎回来，"+data.name;
           $("#span_username").html(msg);
       });
       //查询分类信息
        $.get("findAllServlet",{},function (data) {
            var lis='<li class="nav-active"><a href="index.html">首页</a></li>';
            //变量数组 拼接字符串
            for (var i = 0;i< data.length;i++){
                var li='<li><a href="route_list.html">'+data[i].cname+'</a></li>';

                lis+=li;
            }
            lis+='<li><a href="favoriterank.html">收藏排行榜</a></li>';
            //将list字符串 设置到ul的html内容中
            $("#category").html(lis);

        })
    });

</script>

<header id="header">
        <div class="top_banner">
            <img src="images/top_banner.jpg" alt="">
        </div>
        <div class="shortcut">
            <!-- 未登录状态  -->
            <div class="login_out">
                <a href="login.html">登录</a>
                <a href="register.html">注册</a>
            </div>
            <!-- 登录状态  -->
            <div class="login">
                
                <span id="span_username"></span>
                <a href="myfavorite.html" class="collection">我的收藏</a>
                <a href="javascript:location.href='/exitServlet';">退出</a>
            </div>
        </div>
        <div class="header_wrap">
            <div class="topbar">
                <div class="logo">
                    <a href="/"><img src="images/logo.jpg" alt=""></a>
                </div>
                <div class="search">
                    <input name="" type="text" placeholder="请输入路线名称" class="search_input" autocomplete="off">
                    <a href="javascript:;" class="search-button">搜索</a>
                </div>
                <div class="hottel">
                    <div class="hot_pic">
                        <img src="images/hot_tel.jpg" alt="">
                    </div>
                    <div class="hot_tel">
                        <p class="hot_time">客服热线(9:00-6:00)</p>
                        <p class="hot_num">400-618-9090</p>
                    </div>
                </div>
            </div>
        </div>
    </header>
    <!-- 头部 end -->
     <!-- 首页导航 -->
    <div class="navitem">
        <ul id="category" class="nav">
            <!--<li class="nav-active"><a href="index.html">首页</a></li>
            <li><a href="route_list.html">门票</a></li>
            <li><a href="route_list.html">酒店</a></li>
            <li><a href="route_list.html">香港车票</a></li>
            <li><a href="route_list.html">出境游</a></li>
            <li><a href="route_list.html">国内游</a></li>
            <li><a href="route_list.html">港澳游</a></li>
            <li><a href="route_list.html">抱团定制</a></li>
            <li><a href="route_list.html">全球自由行</a></li>
            <li><a href="favoriterank.html">收藏排行榜</a></li>-->
        </ul>
    </div>