JavaWeb实战之开发网上购物系统(超详细)_Java教程

一、项目描述

基于B/S三层架构设计的购物系统，可以更好地符合"高内聚，低耦合"的设计思想。表现层（UI）通过JSP在浏览器上实现界面展示，通过Servlet接受用户请求并生成验证码等实时信息；数据访问层（DAL）通过JDBC对DBMS进行访问；二者之间的业务逻辑层（BLL）通过Service进行连接。同时面向接口编程提高规范化。这只是我自己用两三天的时间做的小项目，距离真正的购物系统差距还是很大的，仅供初学者参考，很多逻辑缺陷不必太纠结，以后有时间会再写一篇博客对这个项目进行相关测试。

如果只需要代码可直接通过书签栏跳转至相关文件。

二、项目演示

这是购物系统首页，是仿照华为商城设计的，当然也可以说是仿照小米商城，这二者的页面设计并无本质区别，具体实现借助于Bootstrap，商品信息通过后台数据库读取，商品表见下

JavaWeb实战之开发网上购物系统(超详细)

点击任意商品进入详情界面

JavaWeb实战之开发网上购物系统(超详细)

如果此时点击加入购物车会调用Servlet中的doPost方法，进而通过登陆信息是否读取成功判断登陆状态，如果未登录则转至登录界面并提示相关信息，背景渐变色借助于webgradients选取，同时实现正则验证与验证码相关功能

JavaWeb实战之开发网上购物系统(超详细)

我们先注册再登录，这里注册洛的相关信息

JavaWeb实战之开发网上购物系统(超详细)

注册成功

JavaWeb实战之开发网上购物系统(超详细)

之后我们登录并将心仪的商品加入购物车，查看购物车，这里会一致显示当前登录用户信息

JavaWeb实战之开发网上购物系统(超详细)

提交订单后查看订单，这里借助jQuery做了一个下拉框，可以查看后台数据库关于此订单的全部信息，这里提交订单相当于付款，所以未设退货功能，因此数据删除只能借助于后台数据库。

JavaWeb实战之开发网上购物系统(超详细)

最后点击注销返回主页

JavaWeb实战之开发网上购物系统(超详细)

三、部分代码

JdbcUtils.java

用于加载驱动并获得与数据库的连接的工具类

package common;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JdbcUtil {
static Connection connection;
public static Connection getCon() {
//加载驱动
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String url = "jdbc:mysql://localhost:3306/shoppingsystem?characterEncoding=utf-8";
String username = "root";
String password = "123";
//获得连接
try {
connection = DriverManager.getConnection(url, username, password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return connection;
}
public static void closeAll(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (preparedStatement != null) {
try {
preparedStatement.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
、

People.java

与数据库中用户表相匹配的用户类

package entity;
public class People {
private String id;
private String password;
private String name;
private String email;
private String address;
public People() {
super();
// TODO Auto-generated constructor stub
}
public People(String id, String password, String name, String email, String address) {
super();
this.id = id;
this.password = password;
this.name = name;
this.email = email;
this.address = address;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
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 getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "People [id=" + id + ", password=" + password + ", name=" + name + ", email=" + email + ", address="
+ address + "]";
}
}

InterfacePeopleDao.java

对用户信息进行相关操作的接口

package dao;
import java.util.List;
import entity.People;
public interface InterfacePeopleDao {
public abstract int insertPeople(String id, String password, String name, String email, String address);
public abstract int deletePeople(String id);
public abstract int updatePeople(String id, String password, String name, String email, String address);
public abstract People checkPeople(String id, String password);
public abstract List<People> findAllPeople();
}

PeopleDao.java

对上述接口的实现

package dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import common.JdbcUtil;
import entity.People;
public class PeopleDao implements InterfacePeopleDao {
private Connection connection;
private PreparedStatement preparedStatement;
private ResultSet resultSet;
@Override
public int insertPeople(String id, String password, String name, String email, String address) {
String sql = "mistake";
if (id != "" && password != "" && name != "" && email != "" && address != "") {
sql = "insert into people (id, password, name, email, address)" + "values('" + id + "','" +
password + "','" + name + "','" + email + "','" + address + "');";
}
System.out.println("insertPeople()的sql语句:" + sql);
int result = 0;
connection = JdbcUtil.getCon();
try {
preparedStatement = connection.prepareStatement(sql);
} catch (SQLException e) {
e.printStackTrace();
}
try {
result = preparedStatement.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
JdbcUtil.closeAll(connection, preparedStatement, resultSet);
return result;
}
@Override
public int deletePeople(String id) {
// TODO Auto-generated method stub
return 0;
}
@Override
public int updatePeople(String id, String password, String name, String email, String address) {
// TODO Auto-generated method stub
return 0;
}
@Override
public People checkPeople(String id, String password) {
String sql = null;
if (id != null && password != null) {
sql = "select * from people where id = '" + id + "' and password = '" + password + "'";
}
System.out.println("checkPeople()的sql语句:" + sql);
People people = null;
connection = JdbcUtil.getCon();
try {
preparedStatement = connection.prepareStatement(sql);
resultSet = preparedStatement.executeQuery();
if (resultSet.next()) {
people = new People();
people.setId(resultSet.getString(1));
people.setPassword(resultSet.getString(2));
people.setName(resultSet.getString(3));
people.setEmail(resultSet.getString(4));
people.setAddress(resultSet.getString(5));
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtil.closeAll(connection, preparedStatement, resultSet);
}
return people;
}
@Override
public List<People> findAllPeople() {
// TODO Auto-generated method stub
return null;
}
}

InterfacPeopleService.java

在业务逻辑层中将表现层与数据访问层进行连接，由于项目本身并不复杂，所以只是简单实现了方法传递

package service;
import java.util.List;
import entity.People;
public interface InterfacePeopleService {
public abstract int insertPeople(String id, String password, String name, String email, String address);
public abstract int deletePeople(String id);
public abstract int updatePeople(String id, String password, String name, String email, String address);
public abstract People checkPeople(String id, String password);
public abstract List<People> findAllPeople();
}

PeopleService.java

对上述接口的实现

package service;
import java.util.List;
import dao.InterfacePeopleDao;
import dao.PeopleDao;
import entity.People;
public class PeopleService implements InterfacePeopleService {
private InterfacePeopleDao peopleDao;
public PeopleService() {
peopleDao = new PeopleDao();
}
@Override
public int insertPeople(String id, String password, String name, String email, String address) {
return peopleDao.insertPeople(id, password, name, email, address);
}
@Override
public int deletePeople(String id) {
// TODO Auto-generated method stub
return 0;
}
@Override
public int updatePeople(String id, String password, String name, String email, String address) {
// TODO Auto-generated method stub
return 0;
}
@Override
public People checkPeople(String id, String password) {
return peopleDao.checkPeople(id, password);
}
@Override
public List<People> findAllPeople() {
// TODO Auto-generated method stub
return null;
}
}

CheckCode.java

在内存中生成验证码图片并输出到客户端

package servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet("/CheckCode")
public class CheckCode extends HttpServlet {
private static final long serialVersionUID = 1L;
private static int width=70;
private static int height=25;
public CheckCode() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
/**
* request是客户端浏览器发出的请求被封装形成的一个HttpServletRequest公共接口类对象
* session对象存储特定用户会话所需的属性及配置信息, 这样当用户在应用程序的Web页之间跳转时, 存储在session对象中的变量将不会丢失, 而是在整个用户会话中一直存在下去
* getSession()与getSession(true)一样, 获取request对象关联的session对象, 如果没有session, 则返回一个新的session
*/
HttpSession session=request.getSession();
response.setContentType("image/jpeg");// 设置生成的文档类型为jpg
ServletOutputStream servletOutputStream = response.getOutputStream();
/*设置浏览器不要缓存此图片*/
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
/**
* 创建内存图片并获得其图形上下文
* Image是一个抽象类, BufferedImage是其实现类, 是一个带缓冲区图像类, 主要作用是将一幅图片加载到内存中
* BufferedImage生成的图片在内存里有一个图像缓冲区, 利用这个缓冲区我们可以很方便地操作这个图片
*/
BufferedImage image=new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics graphics=image.getGraphics();
char[] rands=generCode();// 产生随机的验证码
drawRands(graphics, rands);// 产生图像
graphics.dispose();// 结束图像的绘制过程，完成图像
/*将图像输出到客户端*/
ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
ImageIO.write(image, "jpeg", byteArrayOutputStream);
byte[] buf=byteArrayOutputStream.toByteArray();
response.setContentLength(buf.length);
servletOutputStream.write(buf);
byteArrayOutputStream.close();
servletOutputStream.close();
session.setAttribute("checkcode", new String(rands));// 将当前的验证码写入到session中
}
private char[] generCode() {
//定义验证码的字符表
String chars="0123456789";
char[] rands=new char[5];
for(int i=0;i<5;i++) {
int rand=(int)(Math.random()*10);
rands[i]=chars.charAt(rand);
}
return rands;
}
private void drawRands(Graphics g,char[] rands) {
g.setColor(Color.WHITE);
g.setFont(new Font(null, Font.ITALIC|Font.BOLD, 18));
/*在不同高度上输出验证码的每个字符*/
g.drawString("" + rands[0], 0, 18);
g.drawString("" + rands[1], 14, 18);
g.drawString("" + rands[2], 28, 18);
g.drawString("" + rands[3], 42, 18);
g.drawString("" + rands[4], 56, 18);
System.out.print("当前验证码:");
System.out.println(rands);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}