HttpSession实现购物车功

应用简介：

• 任务：使用HttpSession实现购物车功能
• 应用程序：实现购物车功能 商品首页列出商品，可以查看商品详情，实现自动登录功能，添加购物车，查看购物车

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java代码部分

/*****************IndexServlet.java*********************************/package controller;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * Servlet implementation class IndexServlet */@WebServlet("/IndexServlet")public class IndexServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public IndexServlet() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        // response.getWriter().append("Served at:        // ").append(request.getContextPath());        Cookie[] cookies = request.getCookies();        String name = null;        String pwd = null;        if (cookies != null) {            for (Cookie cookie : cookies) {                if (cookie.getName().equals("name")) {                    name = cookie.getValue();                }                if (cookie.getName().equals("pwd")) {                    pwd = cookie.getValue();                }            }            if (name == "admin" && pwd == "123") {                request.getRequestDispatcher("index.html").forward(request, response);                return;            } else {                response.sendRedirect("error.html");            }        }        HttpSession session = request.getSession(); // 访问会话对象        String value = (String) session.getAttribute("value"); // 得到创建的value        if (value == "1") {            request.getRequestDispatcher("index.html").forward(request, response);        } else {            System.out.println("跳转到登陆页面--\n");            response.sendRedirect("login.html");        }    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        doGet(request, response);    }}

/****************AddCartServlet.java***************************/package controller;import java.io.IOException;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * Servlet implementation class AddCart */public class AddCartServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public AddCartServlet() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        // 判断Cookie信息是否存在，存在直接添加到购物车，否则显示登录页面        request.setAttribute("test", "Listerner Test");        HttpSession session = request.getSession(); // 访问会话对象        String value = (String) session.getAttribute("value");        Cookie[] cookies = request.getCookies(); // 获取Cookie        System.out.println("获取Cookie\n");        if (value != "1"  cookies == null) {            response.sendRedirect("login.html"); // 如果没有cookie，跳转到login页面            System.out.println("获取Cookie失败！");        } else {            for (Cookie cookie : cookies) {                if (cookie.getName().equals("name")) {                    System.out.println("name" + cookie.getValue());                }                if (cookie.getName().equals("pwd")) {                    System.out.println("pwd" + cookie.getValue());                }            }            System.out.println("存在Cookie");            String name = request.getParameter("name");            String price = request.getParameter("price");            name = new String(name.getBytes("iso-8859-1"), "utf-8");            // price = new String(price.getBytes("iso-8859-1"), "utf-8");            System.out.println("添加的商品为：" + name);            List<String> cart = (List<String>) session.getAttribute("cart");            // 添加价格属性有两种实现方法：            /*             * 1.获取href属性中的price，每添加一次购物车，都要添加价格。             * 2.将cart数据类型转变为Goods型，属性包括：name,price,num，没有获取price方法的麻烦，             * 但是在购物车中删除商品的时候实现困难，所以没有选用这种方式。             */            List<String> prices = (List<String>) session.getAttribute("price");            if (cart == null) {                cart = new ArrayList<String>();                prices = new ArrayList<String>();                cart.add(name);                prices.add(price);            } else {                cart.add(name);                prices.add(price);            }            session.setAttribute("cart", cart);// 将信息存入会话            session.setAttribute("price", prices);            response.sendRedirect("index.html"); // 跳转到商品页面        }    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        this.doGet(request, response);    }}

/*******************DeleteCartServlet.java***************************/package controller;import java.io.IOException;import java.util.List;import javax.servlet.ServletException;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;/** * Servlet implementation class DeleteCartServlet *///@WebServlet("/DeleteCartServlet")public class DeleteCartServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public DeleteCartServlet() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        // response.getWriter().append("Served at:        // ").append(request.getContextPath());        String name = request.getParameter("name");        name = new String(name.getBytes("iso-8859-1"), "utf-8");        HttpSession session = request.getSession(); // 访问会话对象        List<String> cart = (List<String>) session.getAttribute("cart");        System.out.println(name);        cart.remove(name);        session.setAttribute("cart", cart);// 将信息存入会话        response.sendRedirect("showCart");    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        doGet(request, response);    }}

/***************LoginServlet.java******************************/package controller;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class LoginServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public LoginServlet() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        String name = request.getParameter("userName");        String pwd = request.getParameter("userPwd");        // 此处应该访问数据库，查看用户是否存在,查看Cookie，        //默认密码为admin，123        if (name != null && name.equals("admin") && pwd != null && pwd.equals("123")) {            // 会话            HttpSession session = request.getSession(); // 访问会话对象            session.setAttribute("value", "1"); // 创建一个新的属性            String autoLogin = request.getParameter("autoLogin"); // 得到value值            if (autoLogin != null && autoLogin.equals("on")) {                // 响应的处理，保存用户名密码到Cookie中                Cookie c = new Cookie("name", name);                Cookie c2 = new Cookie("pwd", pwd);                c.setMaxAge(60 * 6);                c2.setMaxAge(6 * 60);                // 放到响应中，                response.addCookie(c);                response.addCookie(c2);                System.out.println("用户名密码保存到Cookie中！");            }            System.out.println("跳转到商品详情页面-----");            request.getRequestDispatcher("index.html").forward(request, response);            return;        }        // System.out.println();        response.sendRedirect("login.html");        System.out.println("用户名或密码错误");        // response.encodeRedirectURL("login.html");    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // TODO Auto-generated method stub        this.doGet(request, response);    }}

web.xml文件

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns="http://java.sun.com/xml/ns/javaee"    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"    id="WebApp_ID" version="3.0">    <display-name>shoppingcart</display-name>    <welcome-file-list>        <welcome-file>index.html</welcome-file>        <welcome-file>index.htm</welcome-file>        <welcome-file>index.jsp</welcome-file>        <welcome-file>default.html</welcome-file>        <welcome-file>default.htm</welcome-file>        <welcome-file>default.jsp</welcome-file>    </welcome-file-list>    <servlet>        <servlet-name>AddCartServlet</servlet-name>        <servlet-class>controller.AddCartServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>AddCartServlet</servlet-name>        <url-pattern>/addCart</url-pattern>    </servlet-mapping>    <servlet>        <servlet-name>ShowCartServlet</servlet-name>        <servlet-class>controller.ShowCartServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>ShowCartServlet</servlet-name>        <url-pattern>/showCart</url-pattern>    </servlet-mapping>    <servlet>        <servlet-name>IndexServlet</servlet-name>        <servlet-class>controller.IndexServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>IndexServlet</servlet-name>        <url-pattern>/index.do</url-pattern>    </servlet-mapping>    <servlet>        <servlet-name>LoginServlet</servlet-name>        <servlet-class>controller.LoginServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>LoginServlet</servlet-name>        <url-pattern>/login</url-pattern>    </servlet-mapping>    <servlet>        <servlet-name>DeleteCartServlet</servlet-name>        <servlet-class>controller.DeleteCartServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>DeleteCartServlet</servlet-name>        <url-pattern>/deleteCart</url-pattern>    </servlet-mapping></web-app>

<!--  detailA.html--><!DOCTYPE html><html><head><meta charset="UTF-8"><title>详细信息</title></head><body>    <table>        <tr>            <td>商品名</td> <td>商品A </td>         </tr>                <tr>            <td>商品描述</td> <td>男装</td>         </tr>    </table>    <a href="index.html">返回首页</a>    <a href="addCart?id=1&name=商品A&price=35">添加到购物车</a></body></html>

<!-- detailB.html --><!DOCTYPE html><html><head><meta charset="UTF-8"><title>详细信息</title></head><body>    <table>        <tr>            <td>商品名</td>            <td>商品B</td>        </tr>        <tr>            <td>商品描述</td>            <td>女装</td>        </tr>    </table>    <a href="index.html">返回首页</a>    <a href="addCart?id=2&name=商品B&price=40">添加到购物车</a></body></html>

<!-- detailC.html --><!DOCTYPE html><html><head><meta charset="UTF-8"><title>详细信息</title></head><body>    <table>        <tr>            <td>商品名</td>            <td>商品C</td>        </tr>        <tr>            <td>商品描述</td>            <td>童装</td>        </tr>    </table>    <a href="index.html">返回首页</a>    <a href="addCart?id=3&name=商品C&price=45">添加到购物车</a></body></html>

<!--index.html--><!DOCTYPE html><html><head><meta charset="UTF-8"><title>商品列表</title></head><body>    商品列表为：    <hr/>    <table>        <tr>            <td>商品名</td>            <td>价格</td>            <td colspan="2">操作</td>        </tr>        <tr>            <td>商品A</td>            <td>35</td>            <td><a href="detailA.html">查看详情</a></td>            <td><a href="addCart?id=1&name=商品A&price=35">添加到购物车</a></td>        </tr>        <tr>