Java Web之网上购物系统（注册、登录、浏览商品、添加购物车）

时间：2023-04-04 18:14:44

眼看就要期末了，我的专业课也迎来了第二次的期末作业---------《网上购物系统》。虽然老师的意图是在锻炼我们后台的能力，但是想着还是不利用网上的模板，准备自己写，以来别人写的静态页看不懂，再着可以锻炼自己做网页的能力。所以趁有点小进展就想分享自己的作业进展状态。下面是我页面运行的截图。

Java Web之网上购物系统（注册、登录、浏览商品、添加购物车）Java Web之网上购物系统（注册、登录、浏览商品、添加购物车）

Java Web之网上购物系统（注册、登录、浏览商品、添加购物车）Java Web之网上购物系统（注册、登录、浏览商品、添加购物车）

可能粘贴的图片没有任何的效果可言，下面.jsp字体可以运行你想要的页面效果。

index.jsp

register.jsp

login.jsp

product.jsp

后台代码：

User.java
package cn.edu.aynu.rjxy.bean;

/**

 * 商城用户属性

 * @author Administrator

 *

 */

public class User {

    private String id;

    private String username;

    private String password;

    private String name;

    private String telephone;

    public String getId() {

        return id;

    }

    public void setId(String id) {

        this.id = id;

    }

    public String getUsername() {

        return username;

    }

    public void setUsername(String username) {

        this.username = username;

    }

    public String getPassword() {

        return password;

    }

    public void setPassword(String password) {

        this.password = password;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getTelephone() {

        return telephone;

    }

    public void setTelephone(String telephone) {

        this.telephone = telephone;

    }

}
Product.java
package cn.edu.aynu.rjxy.bean;

/**

 * 商品属性

 * @author Administrator

 *

 */

public class Product {

    private String id;

    private String name;

    private Double price;

    private String category;

    private int pnum;

    private String imgurl;

    private String description;

    public String getId() {

        return id;

    }

    public void setId(String id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public Double getPrice() {

        return price;

    }

    public void setPrice(Double price) {

        this.price = price;

    }

    public String getCategory() {

        return category;

    }

    public void setCategory(String category) {

        this.category = category;

    }

    public int getPnum() {

        return pnum;

    }

    public void setPnum(int pnum) {

        this.pnum = pnum;

    }

    public String getImgurl() {

        return imgurl;

    }

    public void setImgurl(String imgurl) {

        this.imgurl = imgurl;

    }

    public String getDescription() {

        return description;

    }

    public void setDescription(String description) {

        this.description = description;

    }

}
UserDao.java
package cn.edu.aynu.rjxy.dao;

import java.sql.SQLException;

import org.apache.commons.dbutils.QueryRunner;

import org.apache.commons.dbutils.handlers.BeanHandler;

import cn.edu.aynu.rjxy.bean.User;

import cn.edu.aynu.rjxy.utils.JDBCUtils;

/**

 * 对User表的操作

 * @author Administrator

 *

 */

public class UserDao {

    QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());

    /**

     * 添加用户到user表

     * @throws SQLException

     */

    public void add(User user) throws SQLException{

        String sql = "insert into user(id,username,password) values(?,?,?)";

        qr.update(sql, user.getId(),user.getUsername(),user.getPassword());

    }

    /**

     * 通过用户名查找用户

     * @throws SQLException

     */

    public User findByUsername(String username) throws SQLException{

        String sql = "select * from user where username = ?";

        User user = qr.query(sql, new BeanHandler<User>(User.class),username);

        return user;

    }

}
ProductDao.java
package cn.edu.aynu.rjxy.dao;

import java.sql.SQLException;

import java.util.List;

import org.apache.commons.dbutils.QueryRunner;

import org.apache.commons.dbutils.handlers.BeanHandler;

import org.apache.commons.dbutils.handlers.BeanListHandler;

import cn.edu.aynu.rjxy.bean.Product;

import cn.edu.aynu.rjxy.utils.JDBCUtils;

/**

 * 对product表进行增删改查

 * @author Administrator

 *

 */

public class ProductDao {

    QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());

    //查询所有商品

    public List<Product> findAll() throws SQLException{

        String sql = "select * from product";

        List<Product> list = qr.query(sql, new BeanListHandler<Product>(Product.class));

        return list;

    }

    //根据id查找商品

    public Product findProductById(String id) throws SQLException{

        String sql = "select * from product where id=?";

        return qr.query(sql, new BeanHandler<Product>(Product.class),id);

    }

}
UserException
package cn.edu.aynu.rjxy.exception;

public class UserException extends Exception {

    public UserException() {

        super();

    }

    public UserException(String message, Throwable cause) {

        super(message, cause);

    }

    public UserException(String message) {

        super(message);

    }

    public UserException(Throwable cause) {

        super(cause);

    }

}
UserService 
package cn.edu.aynu.rjxy.service;

import java.sql.SQLException;

import cn.edu.aynu.rjxy.bean.User;

import cn.edu.aynu.rjxy.dao.UserDao;

import cn.edu.aynu.rjxy.exception.UserException;

/**

 * 调用dao层的方法

 * @author Administrator

 *

 */

public class UserService {

    private UserDao userDao = new UserDao();

    /**

     * 用户注册

     * 1、检测输入的用户名是否存在，如果存在抛出异常“用户已存在”

     * 2、把输入的用户添加到数据库中的user表

     * @throws UserException

     */

    public void register(User user) throws UserException{

        try {

            //检测用户是否存在

            User u = userDao.findByUsername(user.getUsername());

            //如果存在抛出异常否则添加用户到user表

            if (u != null) {

                throw new UserException("用户已经存在");

            }else{

                userDao.add(user);

            }

        } catch (SQLException e) {

            throw new RuntimeException(e);

        }

    }

    /**

     * 用户登录

     * @throws UserException

     */

    public User login(User user) throws UserException{

        try {

            //根据用户名查询user表得到user对象u

            User u = userDao.findByUsername(user.getUsername());

            /**

             * 如果u为null，说明用户不存在，抛出异常，显示用户不存在

             * 否则说明用户存在，检测u对象中的密码和用户输入的面貌是否一致

             * 如果一致，返回查询到的u否则抛出异常，显示密码错误

             */

                if(u == null){

                    throw new UserException("用户名不存在");

                }

                //查询到的用户密码和用户名输入的密码不一致

                if(!u.getPassword().equals(user.getPassword())){

                    throw new UserException("密码错误");

                }

                return u;

        } catch (SQLException e) {

            throw new RuntimeException(e);

        }

    }

}
ProductService 
package cn.edu.aynu.rjxy.service;

import java.sql.SQLException;

import java.util.List;

import cn.edu.aynu.rjxy.bean.Product;

import cn.edu.aynu.rjxy.dao.ProductDao;

/**

 * 调用ProductDao的方法

 * @author Administrator

 *

 */

public class ProductService {

    private ProductDao pDao = new ProductDao();

    //查询所有商品

    public List<Product> findAll(){

        try {

            return pDao.findAll();

        } catch (SQLException e) {

            throw new RuntimeException(e);

        }

    }

    //查看某一商品

    public Product findById(String id){

        try {

            return pDao.findProductById(id);

        } catch (SQLException e) {

            throw new RuntimeException(e);

        }

    }

}
UserServlet 
package cn.edu.aynu.rjxy.servlet;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import cn.edu.aynu.rjxy.bean.User;

import cn.edu.aynu.rjxy.exception.UserException;

import cn.edu.aynu.rjxy.service.UserService;

import cn.edu.aynu.rjxy.utils.CommonsUtils;

/**

 * 调用UserService里面的方法

 * @author Administrator

 *

 */

public class UserServlet extends HttpServlet {

    private UserService userService = new UserService();

    public void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        this.doPost(request, response);

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        //处理中文乱码

        request.setCharacterEncoding("UTF-8");

        response.setContentType("text/html;charset=UTF-8");

        //获取隐藏字段method的值，并把它转换为int型

        int method = Integer.parseInt(request.getParameter("method"));

        switch (method) {

        case 1:    this.register(request, response);

                break;

        case 2:    this.login(request, response);

                break;

        }

    }

    public void register(HttpServletRequest request, HttpServletResponse response)

        throws ServletException, IOException {

        /**

         * 1、将注册表单中的用户信息封装到user对象中

         * 2、将获取的ＵＵＩＤ值作为ｕｓｅｒ对象的ｉｄ

         * ３、注册，如果发生异常，就到register.jsp页面上显示：用户已存在

         *           如果成功，显示注册成功，3秒后就跳转到index.jsp页面。

         */

        User user = CommonsUtils.toBean(request.getParameterMap(), User.class);

        user.setId(CommonsUtils.uuid());

        try {

            userService.register(user);

            request.setAttribute("msg", "注册成功");

            request.getRequestDispatcher("/jsp/index.jsp").forward(request, response);

        } catch (UserException e) {

            request.setAttribute("msg", e.getMessage());

            //将用户在注册表单中输入的信息保存在request域中，请求转发的register.jsp，目的回显

            request.setAttribute("user", user);

            request.getRequestDispatcher("/jsp/register.jsp").forward(request, response);

        }

    }

    public void login(HttpServletRequest request, HttpServletResponse response)

        throws ServletException, IOException {

        /**

         * 1、将用户登录表单中的信息封装成User对象

         * 2、登录，如果发生异常，就转发到login.jsp页面，显示：异常信息

         *          如果成功，就将查询到的user对象u，存放到session域中

         *          然后转发到shopping.jsp页面，显示：欢迎用户登录

         */

        User user = CommonsUtils.toBean(request.getParameterMap(), User.class);

        System.out.println(user+"-------->");

         try {

            User u = userService.login(user);

            System.out.println(u+">>>>");

            //将u存放到session域中

            request.getSession().setAttribute("user", u);

            request.getRequestDispatcher("/jsp/index.jsp").forward(request, response);

        } catch (UserException e) {

            request.setAttribute("msg", e.getMessage());

            request.setAttribute("user", user); //回显

            request.getRequestDispatcher("/jsp/login.jsp").forward(request, response);

        }

    }

}
ProductServlet 
package cn.edu.aynu.rjxy.servlet;

import java.io.IOException;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import cn.edu.aynu.rjxy.bean.Product;

import cn.edu.aynu.rjxy.service.ProductService;

/**

 * 调用ProductService的方法

 * @author Administrator

 *

 */

public class ProductServlet extends HttpServlet {

    private ProductService ps = new ProductService();

    public void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        this.doPost(request, response);

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        //处理中文乱码

        request.setCharacterEncoding("UTF-8");

        response.setContentType("text/html;charset=UTF-8");

        //获取隐藏字段method的值，并把它转换为int型

        int method = Integer.parseInt(request.getParameter("method"));

        switch (method) {

        case 1:    this.findAll(request, response);

                break;

        case 2:    this.addCart(request, response);

                break;

        }

    }

    //处理查询所有商品的请求

    public void findAll(HttpServletRequest request, HttpServletResponse response)

        throws ServletException, IOException {

        List<Product> list = ps.findAll();

        request.setAttribute("listProduct", list);

        //通过请求转发将商品信息显示在product.jsp页面上

        request.getRequestDispatcher("/jsp/product.jsp").forward(request, response);

}

    //处理添加购物车的请求

    public void addCart(HttpServletRequest request, HttpServletResponse response)

        throws ServletException, IOException {

        //获取商品的id

        String id = request.getParameter("id");

        //得到商品

        Product p = ps.findById(id);

        //购物车是保存在session中

        HttpSession session = request.getSession();

        //从session中拿到购物车

        Map<Product,Integer> cart = (Map<Product, Integer>) session.getAttribute("cart");

        //如果cart不存在，就创建购物车

        if (cart == null) {

            cart = new HashMap<Product,Integer>();

        }

        /**

         * 遍历Map中的所有key也就是商品对象，如果发现有的商品的id和

         * 即将加入购物车的id相同，就在原来的数量上＋1

         */

        Iterator<Product> it = cart.keySet().iterator();

        boolean f = true;

        while (it.hasNext()) {

            Product pp = (Product)it.next();

            if (pp.getId().equals(p.getId())) {

                cart.put(pp, cart.get(pp)+1);

                f = false;

            }

        }

        //如果没有发现购物车原来相同的商品，就直接加入

        if (f) {

            cart.put(p, 1);

        }

        //将cart放入session

        session.setAttribute("cart", cart);

        //重定向

        response.sendRedirect("jsp/cart.jsp");

}

}
CommonsUtils
package cn.edu.aynu.rjxy.utils;

import java.util.Map;

import java.util.UUID;

import org.apache.commons.beanutils.BeanUtils;

import org.apache.commons.beanutils.ConvertUtils;

/**

 * 提供UUID，实现表单数据封装到bean中

 * @author Administrator

 *

 */

public class CommonsUtils {

    /**

     * 返回一个UUID

     * @return

     */

    public static String uuid(){

        return UUID.randomUUID().toString().replace("-", "").toUpperCase();

    }

    /**

     * 把表单数据封装到bean中

     */

    public static <T> T toBean(Map data, Class<T> clazz){

        try{

            T bean = clazz.newInstance();

            BeanUtils.populate(bean, data);

            return bean;

        }catch (Exception e) {

            throw new RuntimeException(e);

        }

    }

}

JDBCUtils

package cn.edu.aynu.rjxy.utils;

import java.sql.Connection;

import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

/**

 * 创建数据库连接池

 * @author Administrator

 *

 */

public class JDBCUtils {

    //读取的是C3P0-config默认配置创建数据库连接池对象

    private static DataSource ds = new ComboPooledDataSource();

    //获取数据库连接池对象

    public static DataSource getDataSource(){

        return ds;

    }

    //从池中获取连接

    public static Connection getConnection() throws SQLException{

        return ds.getConnection();

    }

}

c3p0-config.xml

<?xml version="1.0" encoding="UTF-8"?>

<c3p0-config>

    <!-- 默认配置，当使用ComboPooledDataSource无参构造器时，使用的就是这个配置 -->

    <default-config>

        <!-- 基本配置 -->

        <property name="jdbcUrl">jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8</property>

        <property name="driverClass">com.mysql.jdbc.Driver</property>

        <property name="user">root</property>

        <property name="password">123456</property>

        <!-- 每次增量，当需要创建Connection对象时，一次创建几个 -->

        <property name="acquireIncrement">3</property>

        <!-- 当创建池对象后，池中应该有几个Connection对象 -->

        <property name="initialPoolSize">10</property>

        <!-- 池中最少Connection个数，如果少于这个值，就会创建Connection -->

        <property name="minPoolSize">2</property>

        <!-- 池中最大连接个数 -->

        <property name="maxPoolSize">10</property>

    </default-config>

</c3p0-config>

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