【Java】jsp+servlet实战编写购物商城

Z时代
2024-01-10
分类：技术分享

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项目介绍

开发环境：

jdk 8

intellij idea

tomcat 8

mysql 5.7

所用技术：

jsp+servlet

js+ajax

layui

jdbc+C3P0

运行效果

【Java】jsp+servlet实战编写购物商城

用户信息

【Java】jsp+servlet实战编写购物商城

首页

【Java】jsp+servlet实战编写购物商城

商品列表

【Java】jsp+servlet实战编写购物商城

订单确认

【Java】jsp+servlet实战编写购物商城

后端-销售榜单

【Java】jsp+servlet实战编写购物商城

重要代码:

1.登录，权限角色控制：

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1.获取登录页面输入的用户名与密码
String username = request.getParameter("username"); String password = request.getParameter("password"); // 2.调用service完成登录操作。
UserService service = new UserService(); try { User user = service.login(username, password); // 3.登录成功，将用户存储到session中.
request.getSession().setAttribute("user", user); // 获取用户的角色，其中用户的角色分普通用户和超级用户两种
String role = user.getRole(); // 如果是超级用户，就进入到后台管理系统；否则进入我的账户页面
if ("超级用户".equals(role)) {
response.sendRedirect(request.getContextPath() + "/admin/login/home.jsp"); return; } else { response.sendRedirect(request.getContextPath() + "/client/myAccount.jsp"); return; } } catch (LoginException e) { // 如果出现问题，将错误信息存储到request范围，并跳转回登录页面显示错误信息
e.printStackTrace(); request.setAttribute("register_message", e.getMessage()); request.getRequestDispatcher("/client/login.jsp").forward(request, response); return; }}
// 退出登录，销毁用户缓存信息
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 获取session对象.
HttpSession session = request.getSession();// 销毁session
session.invalidate(); // flag标识
String flag = request.getParameter("flag");// 重定向到首页if (flag == null || flag.trim().isEmpty()) { response.sendRedirect(request.getContextPath() + "/index.jsp"); }}

2.购物车逻辑

// 后端数据组装
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 1.获取美妆id
String id = request.getParameter("id"); // 2.根据id条件查询具体美妆参数信息
ProductService service = new ProductService(); try { Product p = service.findProductById(id); //3.将商品添加到购物车
//3.1获得session对象
HttpSession session = request.getSession(); //3.2从session中获取购物车对象
Map<Product, Integer> cart = (Map<Product, Integer>)session.getAttribute("cart"); //3.3如果购物车为null,说明没有商品存储在购物车中，创建出购物车
if (cart == null) { cart = new HashMap<Product, Integer>(); } //3.4向购物车中添加商品
Integer count = cart.put(p, 1); //3.5如果商品数量不为空，则商品数量+1，否则添加新的商品信息
if (count != null) { cart.put(p, count + 1); }        session.setAttribute("cart", cart);
response.sendRedirect(request.getContextPath() + "/client/cart.jsp"); return; } catch (FindProductByIdException e) { e.printStackTrace(); }}
//jsp 页面数据渲染
<c:forEach items="${cart}" var="entry" varStatus="vs">
<table width="100%" border="0" cellspacing="0"> <tr> <td width="10%">${vs.count}</td> <td width="30%">${entry.key.name }</td> <td width="10%">${entry.key.price }</td> <td width="20%"> <!-- 减少商品数量 --> <input type="button" value='-'                       onclick="changeProductNum('${entry.value-1}','${entry.key.pnum}','${entry.key.id}')">
<!-- 商品数量显示 --> <input name="text" type="text" value="${entry.value}"  /> <!-- 增加商品数量 --> <input type="button" value='+'                       onclick="changeProductNum('${entry.value+1}','${entry.key.pnum}','${entry.key.id}')"></td> <td width="10%">${entry.key.pnum}</td> <td width="10%">${entry.key.price*entry.value}</td> <td width="10%"> <!-- 删除商品 --> <a href="https://segmentfault.com/a/1190000038634015/${pageContext.request.contextPath}/changeCart?id=${entry.key.id}&count=0" onclick="javascript:return cart_del()">X</a> </td> </tr> </table> <c:set value="${total+entry.key.price*entry.value}" var="total" /></c:forEach>

3.文字验证码生成
【Java】jsp+servlet实战编写购物商城

public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 禁止缓存
// response.setHeader("Cache-Control", "no-cache"); // response.setHeader("Pragma", "no-cache"); // response.setDateHeader("Expires", -1); int width = 180; int height = 30; // 步骤一 绘制一张内存中图片
BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 步骤二 图片绘制背景颜色 ---通过绘图对象
Graphics graphics = bufferedImage.getGraphics();// 得到画图对象 --- 画笔
// 绘制任何图形之前 都必须指定一个颜色
graphics.setColor(getRandColor(200, 250)); graphics.fillRect(0, 0, width, height); // 步骤三 绘制边框
graphics.setColor(Color.WHITE); graphics.drawRect(0, 0, width - 1, height - 1); // 步骤四 四个随机数字
Graphics2D graphics2d = (Graphics2D) graphics; // 设置输出字体
graphics2d.setFont(new Font("宋体", Font.BOLD, 18));
Random random = new Random();// 生成随机数
int index = random.nextInt(words.size()); String word = words.get(index-1);// 获得成语
// 定义x坐标
int x = 10; for (int i = 0; i < word.length(); i++) { // 随机颜色
graphics2d.setColor(new Color(20 + random.nextInt(110), 20 + random .nextInt(110), 20 + random.nextInt(110))); // 旋转 -30 --- 30度
int jiaodu = random.nextInt(60) - 30; // 换算弧度
double theta = jiaodu * Math.PI / 180; // 获得字母数字
char c = word.charAt(i); // 将c 输出到图片
graphics2d.rotate(theta, x, 20); graphics2d.drawString(String.valueOf(c), x, 20); graphics2d.rotate(-theta, x, 20); x += 40; } // 将验证码内容保存session
request.getSession().setAttribute("checkcode_session", word); // 步骤五 绘制干扰线
graphics.setColor(getRandColor(160, 200)); int x1; int x2; int y1; int y2; for (int i = 0; i < 30; i++) { x1 = random.nextInt(width); x2 = random.nextInt(12); y1 = random.nextInt(height); y2 = random.nextInt(12); graphics.drawLine(x1, y1, x1 + x2, x2 + y2); } // 将上面图片输出到浏览器 ImageIO graphics.dispose();// 释放资源ImageIO.write(bufferedImage, "jpg", response.getOutputStream());}