书城项目

一、创建项目所需要的包

各个层所对应的包名：
web层：
com.bookmall.web/servlet/controller
service层：
com.bookmall.service   Service接口包
com.bookmall.service.impl   Service接口实现类
dao层：
com.bookmall.dao   Dao接口包
com.bookmall.dao.impl   Dao接口实现类
实体bean对象：
com.bookmall.pojo/entity/domain/bean   JavaBean类
测试包：
com.bookmall.test/junit
工具包：
com.bookmall.utils

二、创建需要的数据库和表

CREATE DATABASE bookmall;

USE bookmall;

CREATE TABLE userinfo(
	 `id` INT PRIMARY KEY auto_increment,
	 `username` VARCHAR(20) NOT NULL,
	 `password` VARCHAR(32) NOT NULL,
	`email` VARCHAR(40)
);

INSERT  INTO userinfo(`username`,`password`,`email`)

VALUES('admin','123456','admin@qq.com');

SELECT * FROM userinfo;

三、编写数据库表对应的 JavaBean 对象

在com.bookmall.bean包下创建User类

package com.bookmall.bean;

public class User {
    private Integer id;
    private String username;
    private String password;
    private String email;

    public User() {
    }

    public User(Integer id, String username, String password, String email) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.email = email;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer 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 getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
    
     @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
}

四、编写工具类JdbcUtils并测试

1.首先导入所需要的jar包：

2.在src目录下创建jdbc.properties 配置文件：

username=root
password=2824199842
url=jdbc:mysql://localhost:3306/bookmall?serverTimezone=Asia/Shanghai
driverClassName=com.mysql.cj.jdbc.Driver
initialSize=10
maxActive=10

3.在com.bookmall.utils下创建 JdbcUtils 类：

package com.bookmall.utils;

public class JdbcUtils {
    private static DruidDataSource dataSource;
    static{
        Properties properties = null;
        try {
            properties = new Properties();
            // 创建输入流 读取jdbc.properties属性配置文件
            InputStream inputStream = JdbcUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");
            // 从流中加载数据
            properties.load(inputStream);
            // 创建数据库连接池
            dataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取数据库连接池中的连接
     * @return 返回连接  否则返回null
     */
    public static Connection getConnection(){
        Connection conn = null;
        try {
            conn = dataSource.getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }

    /**
     * 关闭连接，放回数据库连接池
     * @param conn
     */
    public static void close(Connection conn){
        if(conn!=null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

4.在com.bookmall.test包下创建JdbcUtilsTest类，测试是否连接成功：

package com.bookmall.test;

public class JdbcUtilsTest {
    @Test
    public void testJdbcUtils() {
        Connection conn = JdbcUtils.getConnection();
        System.out.println(conn);
        JdbcUtils.close(conn);
    }
}

五、编写BaseDao

1.导入DBUtils 的jar包：

2.在com.bookmall.dao.impl包下创建BaseDao抽象类：

package com.bookmall.dao.impl;

public abstract class BaseDao {
    // 使用dbutils操作数据库
    private QueryRunner queryRunner = new QueryRunner();

    /**
     * 执行增删改方法
     * @param sql 要执行的sql语句
     * @param args 要填充的占位符
     * @return 执行成功，返回受影响的行数，否则执行失败，返回-1
     */
    public int update(String sql,Object ... args){
        Connection conn = JdbcUtils.getConnection();
        try {
            return queryRunner.update(conn,sql,args);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            JdbcUtils.close(conn);
        }
        return -1;
    }

    /**
     * 执行返回一条结果的查询语句
     * @param type 返回的对象类型
     * @param sql 要执行的sql语句
     * @param args 要填充的占位符
     * @param <T> 返回的类型的泛型
     * @return 执行成功，返回一个指定类型的对象，否则执行失败，返回null
     */
    public <T> T queryForOne(Class<T> type,String sql,Object ... args){
        Connection conn = JdbcUtils.getConnection();
        // BeanHandler是ResultSetHandler接口的一个实现类，用于封装表中的一条记录
        try {
            return queryRunner.query(conn,sql,new BeanHandler<T>(type),args);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            JdbcUtils.close(conn);
        }
        return null;
    }

    /**
     * 执行返回多条结果的查询语句
     * @param type 返回的对象类型
     * @param sql 要执行的sql语句
     * @param args 要填充的占位符
     * @param <T> 返回的类型的泛型
     * @return 执行成功，返回一个指定类型的对象的列表，否则执行失败，返回null
     */
    public <T> List<T> queryForList(Class<T> type, String sql, Object ... args){
        Connection conn = JdbcUtils.getConnection();
        try {
            return queryRunner.query(conn,sql,new BeanListHandler<T>(type),args);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            JdbcUtils.close(conn);
        }
        return null;
    }

    /**
     * 执行返回特殊值（一行一列）的查询
     * @param sql 要执行的sql语句
     * @param args 要填充的占位符
     * @return 执行成功，返回一个值，否则执行失败，返回null
     */
    public Object queryForSingleValue(String sql, Object ... args){
        Connection conn = JdbcUtils.getConnection();
        // ScalarHandler将单个值封装
        try {
            return queryRunner.query(conn,sql,new ScalarHandler(),args);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            JdbcUtils.close(conn);
        }
        return null;
    }
}

六、编写UserDao接口并测试

1.在com.bookmall.dao包下编写UserDao 接口

package com.bookmall.dao;

public interface UserDao {
    /**
     * 根据用户名查询用户信息
     * @param username 用户名
     * @return 执行成功，返回User对象，否则返回null
     */
    public User queryUserByUsername(String username);

    /**
     * 保存用户信息
     * @param user User对象
     * @return 执行成功，返回受影响的行数，否则返回-1
     */
    public int saveUser(User user);

    /**
     *根据用户名和密码查询用户信息
     * @param username
     * @param password
     * @return 执行成功返回User对象，否则返回null说明用户名或密码错误
     */
    public User queryUserByUsernameAndPassword(String username,String password);
}

2.在com.bookmall.dao包下编写UserDao接口实现类UserDaoImpl

package com.book.dao.impl;

public class UserDaoImpl extends BaseDao implements UserDao {
    @Override
    public User queryUserByUsername(String username) {
        String sql = "select `id`,`username`,`password`,`email` from userinfo where username = ?";
        return queryForOne(User.class, sql, username);
    }

    @Override
    public int saveUser(User user) {
        String sql = "insert into userinfo(`username`,`password`,`email`)value(?,?,?)";
        return update(sql, user.getUsername(), user.getPassword(), user.getEmail());
    }

    @Override
    public User queryUserByUsernameAndPassword(String username, String password) {
        String sql = "select `id`,`username`,`password`,`email` from userInfo where username = ? and password = ?";
        return queryForOne(User.class, sql, username, password);
    }
}

3.在com.bookmall.test包下创建UserDaoImplTest测试类(UserDaoImpl类下按ctrl+shift+t快速创建测试类)，测试UserDaoImpl类中的方法。

package com.bookmall.test;

public class UserDaoImplTest {
    UserDao userDao = new UserDaoImpl();
    @Test
    public void queryUserByUsername() {
        if(userDao.queryUserByUsername("admin")!=null){
            System.out.println("用户名可用");
        }else{
        System.out.println("用户名已存在");
        }
    }

    @Test
    public void saveUser() {
        System.out.println(userDao.saveUser(new User(null,"大司马","123456","dsm@qq.com")));
    }

    @Test
    public void queryUserByUsernameAndPassword() {
        if(userDao.queryUserByUsernameAndPassword("admin","123456") == null){
            System.out.println("用户名或密码错误，登录失败！");
        }else{
        System.out.println("登录成功！");
        }
    }
}

七、编写UserService并测试

1.在com.bookmall.service包下创建UserService接口

package com.bookmall.service;

public interface UserService {
    /**
     * 用户注册
     * @param user
     */
    public void registUser(User user);

    /**
     * 用户登录
     * @param user
     * @return
     */
    public User login(User user);

    /**
     * 检查用户名是否可用
     * @param username
     * @return 返回true，表示用户已存在，否则返回false
     */
    public boolean existUsername(String username);
}

2.在com.bookmall.service.impl创建UserService接口实现类UserServiceImpl

package com.bookmall.service.impl;

public class UserServiceImpl implements UserService {
    private UserDao userDao = new UserDaoImpl();
    @Override
    public void registUser(User user) {
        userDao.saveUser(user);
    }

    @Override
    public User login(User user) {
        return userDao.queryUserByUsernameAndPassword(user.getUsername(),user.getPassword());
    }


    @Override
    public boolean existUsername(String username) {
        if(userDao.queryUserByUsername(username)==null){
            // 为null表示不存在，表示可以使用
            return false;
        }
        return true;
    }
}

3.在com.bookmall.test包下创建测试类UserServiceImplTest，测试UserServiceImpl中的方法

package com.bookmall.test;

public class UserServiceImplTest {
    UserService userService = new UserServiceImpl();
    @Test
    public void registUser() {
        userService.registUser(new User(null,"张伟","123456","zw@126.com"));
    }

    @Test
    public void login() {
        System.out.println(userService.login(new User(null,"zyz","123456",null)));
    }

    @Test
    public void existUsername() {
        System.out.println(userService.existUsername("zyz"));// ture

    }
}

八、编写Web层

1.实现注册功能

在com.bookmall.web中创建RegistServlet类
在web.xml文件中配置文件路径

<servlet>
       <servlet-name>RegistServlet</servlet-name>
       <servlet-class>com.bookmall.web.RegistServlet</servlet-class>
   </servlet>
   <servlet-mapping>
       <servlet-name>RegistServlet</servlet-name>
       <url-pattern>/registServlet</url-pattern>
   </servlet-mapping>

package com.bookmall.web;

public class RegistServlet extends HttpServlet {
    private UserService userService = new UserServiceImpl();
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String email = req.getParameter("email");
        String code = req.getParameter("code");
        // 2.检查验证码是否正确====先写死为qwer
        if("qwer".equalsIgnoreCase(code)){
            // 验证码正确
            // 3.检查用户名是否可用
            if(userService.existUsername(username)){
                // true 用户名已存在
                System.out.println("用户名["+username+"]已存在！");
                // 跳转到首页
                req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);
            } else{
                // false 用户名不存在  可以注册
                userService.registUser(new User(null,username,password,email));
                // 跳转到注册成功页面
                req.getRequestDispatcher("/pages/user/regist_success.html").forward(req,resp);
            }
        }else{// 验证码错误
            System.out.println("验证码["+code+"]错误！");
            // 跳转到首页
            req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);
        }
    }
}

2.实现登录功能

在com.bookmall.web中创建LogintServlet类
在web.xml文件中配置文件路径

<servlet>
        <servlet-name>LoginServlet</servlet-name>
        <servlet-class>com.bookmall.web.LoginServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LoginServlet</servlet-name>
        <url-pattern>/loginServlet</url-pattern>
    </servlet-mapping>

package com.bookmall.web;

public class LoginServlet extends HttpServlet {
    private UserService userService = new UserServiceImpl();
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        User loginUser = userService.login(new User(null,username, password, null));
        if(loginUser==null){
                System.out.println("登录失败！");
                // 跳转到首页
                req.getRequestDispatcher("/pages/user/login.html").forward(req,resp);
        }else{
            System.out.println("登录成功！");
                // 跳转到登录成功页面
                req.getRequestDispatcher("/pages/user/login_success.html").forward(req,resp);
        }
    }
}

九、优化代码

1.将多个页面中重复的代码抽取出来：

写入单独的jsp文件中

footer.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<div id="bottom">
      <span>
         尚硅谷书城.Copyright &copy;2015
      </span>
</div>

header.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<% String basePath = request.getContextPath()+"/";%>
<!-- base标签永远固定相对路径跳转  -->
<base href="<%=basePath%>">
<link type="text/css" rel="stylesheet" href="static/css/style.css">
<script type="text/javascript" src="static/script/jquery-3.4.1.js"></script>

login_success_menu.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<div>
    <span>欢迎<span class="um_span">张总</span>光临尚硅谷书城</span>
    <a href="pages/order/order.jsp">我的订单</a>
    <a href="index.jsp">注销</a>&nbsp;&nbsp;
    <a href="index.jsp">返回</a>
</div>

manage_menu.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<div>
    <a href="book_manager">图书管理</a>
    <a href="order_manager">订单管理</a>
    <a href="index.jsp">返回商城</a>
</div>

采用静态包含的方式替换重复的代码：

 <%-- 静态包含 页脚内容--%>
<%@include file="/pages/common/footer.jsp"%>

<%-- 静态包含 base标签、css样式、jquery文件--%>
   <%@include file="/pages/common/head.jsp"%>

 <%-- 静态包含 成功之后的菜单--%>
<%@include file="/pages/common/login_sucess_menu.jsp"%

 <%-- 静态包含 管理菜单--%>
<%@include file="/pages/common/manage_menu.jsp"%>

2.登录、注册错误提示以及表单回显

LoginServlet.java

public class LoginServlet extends HttpServlet {
    private UserService userService = new UserServiceImpl();

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        User loginUser = userService.login(new User(null, username, password, null));
        if (loginUser == null) {
            // System.out.println("登录失败！");
            // 将要回显的错误信息保存到request域中
            req.setAttribute("msg","用户名或密码错误！");
            req.setAttribute("username",username);
            // 跳转到首页
            req.getRequestDispatcher("/pages/user/login.jsp").forward(req, resp);
        } else {
            System.out.println("登录成功！");
            // 跳转到登录成功页面
            req.getRequestDispatcher("/pages/user/login_success.jsp").forward(req, resp);
        }
    }
}

login.jsp

<div class="msg_cont">
   <b></b>
   <span class="errorMsg">
      <%=
         request.getAttribute("msg")==null?"请输入用户名和密码":request.getAttribute("msg")
      %>
   </span>
</div>

<input class="itxt" type="text" placeholder="请输入用户名"
      autocomplete="off" tabindex="1" name="username"
      value="<%=request.getAttribute("username")==null?"":request.getAttribute("username")%>"/>

RegistServlet.java

public class RegistServlet extends HttpServlet {
    private UserService userService = new UserServiceImpl();
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String email = req.getParameter("email");
        String code = req.getParameter("code");
        // 2.检查验证码是否正确====先写死为qwer
        if("qwer".equalsIgnoreCase(code)){
            // 验证码正确
            // 3.检查用户名是否可用
            if(userService.existUsername(username)){
                // true 用户名已存在
                // System.out.println("用户名["+username+"]已存在！");
                // 把回显信息保存到request域中
                req.setAttribute("msg","用户名已存在！");
                req.setAttribute("username",username);
                req.setAttribute("email",email);
                // 跳转到首页
                req.getRequestDispatcher("/pages/user/regist.jsp").forward(req,resp);
            } else{
                // false 用户名不存在  可以注册
                userService.registUser(new User(null,username,password,email));
                // 跳转到注册成功页面
                req.getRequestDispatcher("/pages/user/regist_success.jsp").forward(req,resp);
            }
        }else{// 验证码错误
            // System.out.println("验证码["+code+"]错误！");
            // 把错误信息和回显信息保存到request域中
            req.setAttribute("msg","验证码错误！");
            req.setAttribute("username",username);
            req.setAttribute("email",email);
            // 跳转到首页
            req.getRequestDispatcher("/pages/user/regist.jsp").forward(req,resp);
        }
    }
}

regist.jsp

<span class="errorMsg">
    <%=request.getAttribute("msg")==null?"":request.getAttribute("msg")%>
</span>

<input class="itxt" type="text" placeholder="请输入用户名"
       autocomplete="off" tabindex="1"
       name="username" id="username"
       value="<%=request.getAttribute("username")==null?"":request.getAttribute("username")%>"/>

<input class="itxt" type="text" placeholder="请输入邮箱地址" autocomplete="off" tabindex="1"
       name="email" id="email"
       value="<%=request.getAttribute("email")==null?"":request.getAttribute("email")%>"/>

3.将LoginServlet和RegistServlet合并为UserServlet

public class UserServlet extends HttpServlet {
    private UserService userService = new UserServiceImpl();

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取请求类型
        String action = req.getParameter("action");
        if ("login".equals(action)) {
            login(req, resp);
        } else if ("regist".equals(action)) {
            regist(req, resp);
        }
    }

    /**
     * 处理登录的功能
     *
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void login(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        User loginUser = userService.login(new User(null, username, password, null));
        if (loginUser == null) {
            // System.out.println("登录失败！");
            // 将要回显的错误信息保存到request域中
            req.setAttribute("msg", "用户名或密码错误！");
            req.setAttribute("username", username);
            // 跳转到首页
            req.getRequestDispatcher("/pages/user/login.jsp").forward(req, resp);
        } else {
            // System.out.println("登录成功！");
            // 跳转到登录成功页面
            req.getRequestDispatcher("/pages/user/login_success.jsp").forward(req, resp);
        }
    }

    /**
     * 处理注册的功能
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void regist(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String email = req.getParameter("email");
        String code = req.getParameter("code");
        // 2.检查验证码是否正确====先写死为qwer
        if ("qwer".equalsIgnoreCase(code)) {
            // 验证码正确
            // 3.检查用户名是否可用
            if (userService.existUsername(username)) {
                // true 用户名已存在
                // System.out.println("用户名["+username+"]已存在！");
                // 把回显信息保存到request域中
                req.setAttribute("msg", "用户名已存在！");
                req.setAttribute("username", username);
                req.setAttribute("email", email);
                // 跳转到首页
                req.getRequestDispatcher("/pages/user/regist.jsp").forward(req, resp);
            } else {
                // false 用户名不存在  可以注册
                userService.registUser(new User(null, username, password, email));
                // 跳转到注册成功页面
                req.getRequestDispatcher("/pages/user/regist_success.jsp").forward(req, resp);
            }
        } else {// 验证码错误
            // System.out.println("验证码["+code+"]错误！");
            // 把错误信息和回显信息保存到request域中
            req.setAttribute("msg", "验证码错误！");
            req.setAttribute("username", username);
            req.setAttribute("email", email);
            // 跳转到首页
            req.getRequestDispatcher("/pages/user/regist.jsp").forward(req, resp);
        }
    }
}

login.jsp

regist.jsp

4.使用反射优化大量else if 代码

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    // 通过反射根据action属性值调用相应的方法
    String action = req.getParameter("action");
    try {
        Method method = UserServlet.class.getDeclaredMethod(action, HttpServletRequest.class, HttpServletResponse.class);
        method.invoke(this,req, resp);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

5.抽取BaseServlet

package com.bookmall.web;

public abstract class BaseServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        // 获取请求类型
        String action = req.getParameter("action");
        // System.out.println(action);
        try {// 通过反射根据action属性值调用相应的方法
            Method method = this.getClass().getDeclaredMethod(action, HttpServletRequest.class, HttpServletResponse.class);
            method.invoke(this, req, resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

package com.bookmall.web;

public class UserServlet extends BaseServlet {
    private UserService userService = new UserServiceImpl();
    protected void login(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // ......
    }

    protected void regist(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    	// ......
    }
}

6.数据的封装和抽取 BeanUtils的使用

BeanUtils工具类，可以一次性的把所有请求的参数注入导JavaBean中
1、导入需要的jar 包：
commons-beanutils-1.8.0.jar
commons-logging-1.1.1jar
2、使用BeanUtils类方法实现注入

package com.bookmall.utils;

public class WebUtils {
    public static <T> T copyParamToBean(Map map, T bean){
        // 将所有请求的参数封装到bean中
        try {
            BeanUtils.populate(bean,map);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bean;
    }
}

UserServlet.java

// 将请求参数一次性封装到user对象中
User user = WebUtils.copyParamToBean(req.getParameterMap(),new User());

7.使用EL表达式修改表单回显

login.jsp

<%--
    <%= request.getAttribute("msg")==null?"请输入用户名和密码":request.getAttribute("msg")%>
--%>
${empty requestScope.msg ? "请输入用户名和密码":requestScope.msg}

<%--
    value="<%=request.getAttribute("username")==null?"":request.getAttribute("username")%>"
--%>
value="${requestScope.username}"

regist.jsp

<%--
    <%=request.getAttribute("msg")==null?"":request.getAttribute("msg")%>
--%>
${requestScope.msg}

<%--
    value="<%=request.getAttribute("username")==null?"":request.getAttribute("username")%>"
--%>
${requestScope.username}

<%--
    value="<%=request.getAttribute("email")==null?"":request.getAttribute("email")%>"
--%>
${requestScope.email}

十、图书模块

1.创建图书模块的数据库表

USE bookmall;
CREATE TABLE book(
	`id` INT PRIMARY KEY auto_increment,
	`name` VARCHAR(50) NOT NULL,
	`price` DECIMAL(8,2) NOT NULL,
	`author` VARCHAR(50) NOT NULL,
	`sales` INT NOT NULL,
	`stock` INT NOT NULL,
	`img_path` VARCHAR(100) NOT NULL
);
# drop table book;

## 插入初始化测试数据
insert into book(`id` , `name` , `author` , `price` , `sales` , `stock` , `img_path`) 
values(null , 'java从入门到放弃' , '国哥' , 80 , 9999 , 9 , 'static/img/default.jpg');

insert into book(`id` , `name` , `author` , `price` , `sales` , `stock` , `img_path`) 
values(null , '数据结构与算法' , '严敏君' , 78.5 , 6 , 13 , 'static/img/default.jpg');

insert into book(`id` , `name` , `author` , `price` , `sales` , `stock` , `img_path`) 
values(null , '编程珠玑' , 'Tom' , 68, 99999 , 52 , 'static/img/default.jpg');

insert into book(`id` , `name` , `author` , `price` , `sales` , `stock` , `img_path`) 
values(null , '从你的全世界路过' , '张嘉加' , 16, 1000 , 50 , 'static/img/cover.jpg');

insert into book(`id` , `name` , `author` , `price` , `sales` , `stock` , `img_path`) 
values(null , 'C语言程序设计' , '谭浩强' , 28 , 52 , 74 , 'static/img/default.jpg');

2.编写图书模块的JavaBean对象

package com.bookmall.bean;

public class Book {
    private Integer id;
    private String name;
    private String author;
    private BigDecimal price;
    private Integer sales;
    private Integer stock;
    private String imgPath;

    public Book() {
    }

    public Book(Integer id, String name, String author, BigDecimal price, Integer sales, Integer stock, String imgPath) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.price = price;
        this.sales = sales;
        this.stock = stock;
        if (imgPath != null && "".equals(imgPath)) {
            this.imgPath = imgPath;
        }
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public Integer getSales() {
        return sales;
    }

    public void setSales(Integer sales) {
        this.sales = sales;
    }

    public Integer getStock() {
        return stock;
    }

    public void setStock(Integer stock) {
        this.stock = stock;
    }

    public String getImgPath() {
        return imgPath;
    }

    public void setImgPath(String imgPath) {
        if (imgPath != null && "".equals(imgPath)) {
            this.imgPath = imgPath;
        }
    }

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", sales=" + sales +
                ", stock=" + stock +
                ", imgPath='" + imgPath + '\'' +
                '}';
    }
}

3.编写图书模块的DAO并测试

package com.bookmall.dao.impl;

public class BookDaoImpl extends BaseDao implements BookDao {
    @Override
    public int addBook(Book book) {
        String sql = "insert into book(`name`,`author`,`price`,`sales`,`stock`,`img_path`) values(?,?,?,?,?,?)";
        return update(sql, book.getName(),book.getAuthor(),book.getPrice(),book.getSales(),book.getStock(),book.getImgPath());
    }

    @Override
    public int deleteBook(Integer id) {
        String sql = "delete from book where id = ?";
        return update(sql,id);
    }

    @Override
    public int updateBook(Book book) {
        String sql = "update book set `name`=?,`author`=?,`price`=?,`sales`=?,`stock`=?,`img_path`= ? where id = ?";
        return update(sql,book.getName(),book.getAuthor(),book.getPrice(),book.getSales(),book.getStock(),book.getImgPath(),book.getId());
    }

    @Override
    public Book queryBookById(Integer id) {
        String sql = "select `id`,`name`,`author`,`price`,`sales`,`stock`,`img_path` imgPath from book where id = ?";
        return queryForOne(Book.class,sql,id);
    }

    @Override
    public List<Book> queryBooks() {
        String sql = "select `id`,`name`,`author`,`price`,`sales`,`stock`,`img_path` imgPath from book";
        return queryForList(Book.class,sql);
    }
}

package com.bookmall.test;

public class BookDaoImplTest {
    private BookDao bookDao = new BookDaoImpl();

    @Test
    public void addBook() {
        bookDao.addBook(new Book(null,"算法与数据结构(java版)","张三三",new BigDecimal(58.80),20,100,"static/img/default.jpg"));
    }

    @Test
    public void deleteBook() {
        bookDao.deleteBook(1);
    }

    @Test
    public void updateBook() {
        bookDao.updateBook(new Book(21,"算法与数据结构(C++版)","张三三",new BigDecimal(58.80),20,100,"static/img/default.jpg"));
    }

    @Test
    public void queryBookById() {
        System.out.println(bookDao.queryBookById(21));
    }

    @Test
    public void queryBooks() {
        for(Book book:bookDao.queryBooks()){
            System.out.println(book);
        }
    }
}

4.编写图书模块的Service并测试

package com.bookmall.service.impl;

public class BookServiceImpl implements BookService {
    private BookDao bookDao = new BookDaoImpl();

    @Override
    public void addBook(Book book) {
        bookDao.addBook(book);
    }

    @Override
    public void deleteBook(Integer id) {
        bookDao.deleteBook(id);
    }

    @Override
    public void updateBook(Book book) {
        bookDao.updateBook(book);
    }

    @Override
    public Book queryBookById(Integer id) {
        return bookDao.queryBookById(id);
    }

    @Override
    public List<Book> queryBooks() {
        return bookDao.queryBooks();
    }
}

package com.bookmall.test;

public class BookServiceImplTest {
    private BookService bookService = new BookServiceImpl();
    @Test
    public void addBook() {
        bookService.addBook(new Book(null,"肉蛋葱鸡","马老师",new BigDecimal(66.66),666,66,"static/img/cover.jpg"));
    }

    @Test
    public void deleteBook() {
        bookService.deleteBook(10);
    }

    @Test
    public void updateBook() {
        bookService.updateBook(new Book(7,"红皮烤鸭","马老师",new BigDecimal(99.8),100,2,"static/img/cover.jpg"));
    }

    @Test
    public void queryBookById() {
        System.out.println(bookService.queryBookById(7));
    }

    @Test
    public void queryBooks() {
        for(Book book :bookService.queryBooks()){
            System.out.println(book);
        }
    }
}

5.编写图书模块的Web层，和页面联调测试

1、实现展示全部图书

在BookServlet.java中添加list()方法用于展示全部图书信息：

private BookService bookService = new BookServiceImpl();
protected void list(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    // 1.通过BookService查询全部图书
    List<Book> books = bookService.queryBooks();
    // 2.将全部的图书信息保存到request域中
    req.setAttribute("books",books);
    // 3.请求转发
    req.getRequestDispatcher("/pages/manager/book_manager.jsp").forward(req,resp);
}

修改图书管理页面的跳转地址：

利用JSTL标签库遍历图书信息在jsp页面中输出：
1、导入JSTL标签库的jar包
taglibs-standard-impl-1.2.1.jar
taglibs-standard-spec-1.2.1.jar
2、在book_manager.jsp中编写遍历图书信息的代码

<c:forEach items="${requestScope.books}" var="book">
	<tr>
		<td>${book.name}</td>
		<td>${book.price}</td>
		<td>${book.author}</td>
		<td>${book.sales}</td>
		<td>${book.stock}</td>
		<td><a href="book_edit">修改</a></td>
		<td><a href="#">删除</a></td>
    </tr>
</c:forEach>

2、实现添加图书

在BookServlet中添加add()方法用于添加图书：

protected void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //  1、获取请求的参数==封装成为Book对象
        Book book = WebUtils.copyParamToBean(req.getParameterMap(), new Book());
        //  2、调用BookService.addBook()保存图书
        bookService.addBook(book);
        // 3、跳到图书列表页面 /manager/bookServlet?action=list
        // 请求转发会造成表单的多次提交
        // req.getRequestDispatcher("/manager/bookServlet?action=list").forward(req, resp);

        // 请求重定向
        resp.sendRedirect(req.getContextPath()+ "/manager/bookServlet?action=list");
    }

修改book_edit.jsp：

3、实现删除图书

在BookServlet中添加delete()方法：

protected void delete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       // 1、获取图书id
       int id = WebUtils.parseInt(req.getParameter("id"),0);
       // 2、调用BookService.deleteById() 删除图书
       bookService.deleteBook(id);
       // 3、重定向 /manager/bookServlet?action=list
       resp.sendRedirect(req.getScheme()+"://"+ req.getServerName()+":"+
               req.getServerPort()+req.getContextPath()+ "/manager/bookServlet?action=list");
   }

修改book_manager.jsp：

添加确认删除提示：
给a标签添加class属性用于对标签选择
给a标签绑定单击事件：

 <%-- 给删除按钮绑定单击事件 用于删除操作的确认	--%>
<script type="text/javascript">
    // 在事件的function函数中，有一个this对象，表示当前正在响应事件的dom对象
	$(function () {
		$("a.deleteClass").click(function(){
			// 确认返回true  取消返回false
			return confirm("你确定删除《" + $(this).parent().parent().find("td:first").text() +"》吗？");
			// return false; 阻止元素的默认行为  不提交
		});
	});
</script>

4、实现修改图书

在bookServlet中添加getBook()用于获取要修改图书的信息：

protected void getBook(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       // 1.获取id
       int id = WebUtils.parseInt(req.getParameter("id"),0);
       // 2.调用BookService.queryBookById() 获取图书信息
       Book book = bookService.queryBookById(id);
       // 3.将图书信息保存至request域中
       req.setAttribute("book",book);
       // 4.请求转发到 /pages/manager/book_edit.jsp
       req.getRequestDispatcher("/pages/manager/book_edit.jsp").forward(req,resp);
   }

修改book_edit.jsp让数据回显：

在BookServlet中添加update()方法：

protected void update(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    // 1.获取从book_edit.jsp提交的表单数据  将数据封装到book对象中
    Book book = WebUtils.copyParamToBean(req.getParameterMap(),new Book());
    // 2.调用BookService.update()更新图书
    bookService.updateBook(book);
    // 3.重定向 manager/bookServlet?action=list 刷新图书列表
    resp.sendRedirect(req.getContextPath()+ "/manager/bookServlet?action=list");
}

在book_edit.jsp中添加隐藏域用于回传修改图书所需要的id值：

图书信息并没有发生修改的原因：
book_edit.jsp页面中既要进行添加add操作，又要进行修改update操作，最终进行何种操作是根据一个隐藏域决定的，因此需要动态修改隐藏域：在请求发起时附带上要执行操作的值，并注入隐藏域中。
传入update参数：
传入add参数：
注入隐藏域：

5、实现图书的分页

创建Page对象：

package com.bookmall.bean;

import java.util.List;
/**
 * Page为分页的模型
 * @param <T> 是具体的模块的 JavaBean 对象
 */
public class Page<T> {
    public static final Integer PAGE_SIZE = 4;
    // 当前页码
    private Integer pageNo;
    // 总页码
    private Integer pageTotal;
    // 总记录数
    private Integer pageTotalCount;
    // 每页显示的数量
    private Integer pageSize = PAGE_SIZE;
    // 当前页的数据
    private List<T> items;

    public Page() {
    }

    public Page(Integer pageNo, Integer pageTotal, Integer pageTotalCount, Integer pageSize, List<T> items) {
        this.pageNo = pageNo;
        this.pageTotal = pageTotal;
        this.pageTotalCount = pageTotalCount;
        this.pageSize = pageSize;
        this.items = items;
    }

    public static Integer getPageSize() {
        return PAGE_SIZE;
    }

    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }

    public List<T> getItems() {
        return items;
    }

    public void setItems(List<T> items) {
        this.items = items;
    }

    public Integer getPageNo() {
        return pageNo;
    }

    public void setPageNo(Integer pageNo) {
        // 对页码进行检查
        if(pageNo<1){
            pageNo = 1;
        }
        if (pageNo>pageTotal){
            pageNo = pageTotal;
        }
        this.pageNo = pageNo;
    }

    public Integer getPageTotal() {
        return pageTotal;
    }

    public void setPageTotal(Integer pageTotal) {
        this.pageTotal = pageTotal;
    }

    public Integer getPageTotalCount() {
        return pageTotalCount;
    }

    public void setPageTotalCount(Integer pageTotalCount) {
        this.pageTotalCount = pageTotalCount;
    }

    @Override
    public String toString() {
        return "Page{" +
                "pageNo=" + pageNo +
                ", pageTotal=" + pageTotal +
                ", pageTotalCount=" + pageTotalCount +
                ", pageSize=" + pageSize +
                ", items=" + items +
                '}';
    }
}

在BookServlet中添page()用于处理分页：

protected void page(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取js页面传来的请求参数 pageNo 和 pageSize
        int pageNo = WebUtils.parseInt(req.getParameter("pageNo"),1);
        int pageSize = WebUtils.parseInt(req.getParameter("pageSize"), Page.PAGE_SIZE);
        // 2.调用BookService.page(pageNo,pageSize) 得到Page对象
        Page<Book> page = bookService.page(pageNo, pageSize);
        // 3.将Page对象保存到Request域中
        req.setAttribute("page",page);
        // 4.请求转发到 /pages/manager/book_manager.jsp
        req.getRequestDispatcher("/pages/manager/book_manager.jsp").forward(req,resp);
    }

在BookService中添加page(pageNo,pageSize) 获取page对象：

/**
     * 查询分页
     * @param pageNo
     * @param pageSize
     * @return 返回一个Page对象
     */
    public Page<Book> page(int pageNo, int pageSize);

在BookServiceImpl中实现page(pageNo,pageSize)：

@Override
   public Page<Book> page(int pageNo, int pageSize) {
       Page<Book> bookPage = new Page<>();
       //设置每页显示的数量
       bookPage.setPageSize(pageSize);
       // 设置总记录数
       Integer pageTotalCount = bookDao.queryForPageTotalCount();
       bookPage.setPageTotalCount(pageTotalCount);
       // 设置总页码
       Integer pageTotal = pageTotalCount/pageSize;
       if (pageTotalCount % pageSize>0){
           pageTotal++;
       }
       bookPage.setPageTotal(pageTotal);
       // 设置当前页码
       bookPage.setPageNo(pageNo);
       // 设置当页数据
       int begin = (bookPage.getPageNo()-1)*pageSize;
       bookPage.setItems(bookDao.queryForItems(begin,pageSize));
       return bookPage;
   }

在BookDao中添加queryForPageTotal()和queryForItems()方法：

/**
 * 查询图书的总记录数
 * @return
 */
public Integer queryForPageTotalCount();

/**
 * 查询当前页面的图书记录
 * @param begin
 * @param pageSize
 * @return
 */
List<Book> queryForItems(int begin, int pageSize);

在BookDaoImpl中实现queryForPageTotal()和queryForItems()方法：

@Override
public Integer queryForPageTotalCount() {
    String sql = "select count(*) from book";
    Number count = (Number) queryForSingleValue(sql);
    return  count.intValue();
}

@Override
public List<Book> queryForItems(int begin, int pageSize) {
    String sql = " select `id`, `name`,`author`,`price`,`sales`,`stock`,`img_path` imgPath from book limit ?,?";
    return queryForList(Book.class,sql,begin,pageSize);
}

修改manage_menu.jsp页面显示分页后的内容：

修改book_manage.jsp页面，让下方显示页面跳转的功能按键：

<script type="text/javascript">
       // 在事件的function函数中，有一个this对象，表示当前正在响应事件的dom对象
       $(function () {
           <%-- 给删除按钮绑定单击事件 用于删除操作的确认	--%>
           $("a.deleteClass").click(function () {
               // 确认返回true  取消返回false
               return confirm("你确定删除《" + $(this).parent().parent().find("td:first").text() + "》吗？");
               // return false; 阻止元素的默认行为  不提交
           });

           $("#searchPageBtn").click(function () {
               var pageNo = $("#pn_input").val();
               location.href = "${pageScope.basePath}manager/bookServlet?action=page&pageNo=" + pageNo;
           });
       });
   </script>

修改hesd.jsp 将basePath保存至pageContext域中：供指定页面跳转时使用

<div id="page_nav">
    <%-- 大于首页才显示--%>
    <c:if test="${requestScope.page.pageNo>1}">
        <a href="manager/bookServlet?action=page&pageNo=1">首页</a>
        <a href="manager/bookServlet?action=page&pageNo=${requestScope.page.pageNo-1}">上一页</a>
    </c:if>

    <%--  页码输出的开始--%>
    <c:choose>
        <%-- 情况1：如果总页码<=5,页码的范围是1~总页码 --%>
        <c:when test="${requestScope.page.pageTotal<=5}">
            <c:forEach begin="1" end="${requestScope.page.pageTotal}" var="i">
                <c:if test="${requestScope.page.pageNo==i}">
                    【${i}】
                </c:if>
                <c:if test="${requestScope.page.pageNo!=i}">
                    <a href="manager/bookServlet?action=page&pageNo=${i}">${i}</a>
                </c:if>
            </c:forEach>
        </c:when>
        <%--情况2：总页码>5 --%>
        <c:when test="${requestScope.page.pageTotal>5}">
            <c:choose>
                <%-- 当前页码为前面3个：页码范围是：1~5--%>
                <c:when test="${requestScope.page.pageNo<=3}">
                    <c:forEach begin="1" end="5" var="i">
                        <c:if test="${requestScope.page.pageNo==i}">
                            【${i}】
                        </c:if>
                        <c:if test="${requestScope.page.pageNo!=i}">
                            <a href="manager/bookServlet?action=page&pageNo=${i}">${i}</a>
                        </c:if>
                    </c:forEach>
                </c:when>
                <%-- 当前页码为后面3个：页码范围是：当前页码-2~末页--%>
                <c:when test="${requestScope.page.pageNo>=requestScope.page.pageTotal-2}">
                    <c:forEach begin="${requestScope.page.pageNo-4}" end="${requestScope.page.pageTotal}" var="i">
                        <c:if test="${requestScope.page.pageNo==i}">
                            【${i}】
                        </c:if>
                        <c:if test="${requestScope.page.pageNo!=i}">
                            <a href="manager/bookServlet?action=page&pageNo=${i}">${i}</a>
                        </c:if>
                    </c:forEach>
                </c:when>
                <%-- 当前页码为中间3个：页码范围是：当前页码-2~当前页码+2--%>
                <c:otherwise>
                    <c:forEach begin="${requestScope.page.pageNo-2}" end="${requestScope.page.pageNo+2}" var="i">
                        <c:if test="${requestScope.page.pageNo==i}">
                            【${i}】
                        </c:if>
                        <c:if test="${requestScope.page.pageNo!=i}">
                            <a href="manager/bookServlet?action=page&pageNo=${i}">${i}</a>
                        </c:if>
                    </c:forEach>
                </c:otherwise>
            </c:choose>
        </c:when>
    </c:choose>
    <%--  页码输出的结束--%>

    <%--  小于末页才显示--%>
    <c:if test="${requestScope.page.pageNo<requestScope.page.pageTotal}">
        <a href="manager/bookServlet?action=page&pageNo=${requestScope.page.pageNo+1}">下一页</a>
        <a href="manager/bookServlet?action=page&pageNo=${requestScope.page.pageTotal}">末页</a>
    </c:if>
    共${requestScope.page.pageTotal}页，${requestScope.page.pageTotalCount}条记录
    到第<input value="${param.pageNo}" name="pn" id="pn_input"/>页
    <input id="searchPageBtn" type="button" value="确定">
</div>

修改增删改操作的重定向地址并传入pageNo参数：

在book_manager.jsp传入页码pageNo：

在book_edit.jsp中添加隐藏域用于传递pageNo给BookServlet：

前台图书的分页展示：|

web目录下的index.jsp只负责转发：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%--只负责请求转发--%>
<jsp:forward page="/client/clientBookServlet?action=page"></jsp:forward>

创建ClientBookServlet用于处理前台的分页请求：

package com.bookmall.web;

public class ClientBookServlet extends BaseServlet {

    private BookService bookService = new BookServiceImpl();
    /**
     * 处理图书分页
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void page(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("经过了前台的ClientBookServlet");
        // 1.获取js页面传来的请求参数 pageNo 和 pageSize
        int pageNo = WebUtils.parseInt(req.getParameter("pageNo"),1);
        int pageSize = WebUtils.parseInt(req.getParameter("pageSize"), Page.PAGE_SIZE);
        // 2.调用BookService.page(pageNo,pageSize) 得到Page对象
        Page<Book> page = bookService.page(pageNo, pageSize);
        // 3.将Page对象保存到Request域中
        req.setAttribute("page",page);
        // 4.请求转发到 /pages/client/index.jsp
        req.getRequestDispatcher("/pages/client/index.jsp").forward(req,resp);
    }
}

在web目录的/page/client/路径下创建index.jsp用于显示前台图书信息：

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>书城首页</title>
    <%-- 静态包含 base标签、css样式、jquery文件   --%>
    <%@include file="/pages/common/head.jsp" %>
    <script type="text/javascript">
        $(function(){
            $("#searchPageBtn").click(function(){
                var pageNo = $("#pn_input").val();
                location.href = "${pageScope.basePath}client/clientBookServlet?action=page&pageNo="+pageNo;
            });
        })
    </script>
</head>
<body>

<div id="header">

    <span class="wel_word">网上书城</span>
    <div>
        <a href="pages/user/login.jsp">登录</a> |
        <a href="pages/user/regist.jsp">注册</a> &nbsp;&nbsp;
        <a href="pages/cart/cart.jsp">购物车</a>
        <a href="pages/manager/manager.jsp">后台管理</a>
    </div>
</div>
<div id="main">
    <div id="book">
        <div class="book_cond">
            <form action="" method="get">
                价格：<input id="min" type="text" name="min" value=""> 元 -
                <input id="max" type="text" name="max" value=""> 元
                <input type="submit" value="查询"/>
            </form>
        </div>
        <div style="text-align: center">
            <span>您的购物车中有3件商品</span>
            <div>
                您刚刚将<span style="color: red">时间简史</span>加入到了购物车中
            </div>
        </div>
        <c:forEach items="${requestScope.page.items}" var="book">
            <div class="b_list">
                <div class="img_div">
                    <img class="book_img" alt="" src="${book.imgPath}"/>
                </div>
                <div class="book_info">
                    <div class="book_name">
                        <span class="sp1">书名:</span>
                        <span class="sp2">${book.name}</span>
                    </div>
                    <div class="book_author">
                        <span class="sp1">作者:</span>
                        <span class="sp2">${book.author}</span>
                    </div>
                    <div class="book_price">
                        <span class="sp1">价格:￥</span>
                        <span class="sp2">${book.price}</span>
                    </div>
                    <div class="book_sales">
                        <span class="sp1">销量:</span>
                        <span class="sp2">${book.sales}</span>
                    </div>
                    <div class="book_amount">
                        <span class="sp1">库存:</span>
                        <span class="sp2">${book.stock}</span>
                    </div>
                    <div class="book_add">
                        <button>加入购物车</button>
                    </div>
                </div>
            </div>
        </c:forEach>
    </div>

    <div id="page_nav">
        <%-- 大于首页才显示--%>
        <c:if test="${requestScope.page.pageNo>1}">
            <a href="client/clientBookServlet?action=page&pageNo=1">首页</a>
            <a href="client/clientBookServlet?action=page&pageNo=${requestScope.page.pageNo-1}">上一页</a>
        </c:if>

        <%--  页码输出的开始--%>
        <c:choose>
            <%-- 情况1：如果总页码<=5,页码的范围是1~总页码 --%>
            <c:when test="${requestScope.page.pageTotal<=5}">
                <c:forEach begin="1" end="${requestScope.page.pageTotal}" var="i">
                    <c:if test="${requestScope.page.pageNo==i}">
                        【${i}】
                    </c:if>
                    <c:if test="${requestScope.page.pageNo!=i}">
                        <a href="client/clientBookServlet?action=page&pageNo=${i}">${i}</a>
                    </c:if>
                </c:forEach>
            </c:when>
            <%--情况2：总页码>5 --%>
            <c:when test="${requestScope.page.pageTotal>5}">
                <c:choose>
                    <%-- 当前页码为前面3个：页码范围是：1~5--%>
                    <c:when test="${requestScope.page.pageNo<=3}">
                        <c:forEach begin="1" end="5" var="i">
                            <c:if test="${requestScope.page.pageNo==i}">
                                【${i}】
                            </c:if>
                            <c:if test="${requestScope.page.pageNo!=i}">
                                <a href="client/clientBookServlet?action=page&pageNo=${i}">${i}</a>
                            </c:if>
                        </c:forEach>
                    </c:when>
                    <%-- 当前页码为后面3个：页码范围是：当前页码-2~末页--%>
                    <c:when test="${requestScope.page.pageNo>=requestScope.page.pageTotal-2}">
                        <c:forEach begin="${requestScope.page.pageNo-4}" end="${requestScope.page.pageTotal}" var="i">
                            <c:if test="${requestScope.page.pageNo==i}">
                                【${i}】
                            </c:if>
                            <c:if test="${requestScope.page.pageNo!=i}">
                                <a href="client/clientBookServlet?action=page&pageNo=${i}">${i}</a>
                            </c:if>
                        </c:forEach>
                    </c:when>
                    <%-- 当前页码为中间3个：页码范围是：当前页码-2~当前页码+2--%>
                    <c:otherwise>
                        <c:forEach begin="${requestScope.page.pageNo-2}" end="${requestScope.page.pageNo+2}" var="i">
                            <c:if test="${requestScope.page.pageNo==i}">
                                【${i}】
                            </c:if>
                            <c:if test="${requestScope.page.pageNo!=i}">
                                <a href="client/clientBookServlet?action=page&pageNo=${i}">${i}</a>
                            </c:if>
                        </c:forEach>
                    </c:otherwise>
                </c:choose>
            </c:when>
        </c:choose>
        <%--  页码输出的结束--%>

        <%--  小于末页才显示--%>
        <c:if test="${requestScope.page.pageNo<requestScope.page.pageTotal}">
            <a href="client/clientBookServlet?action=page&pageNo=${requestScope.page.pageNo+1}">下一页</a>
            <a href="client/clientBookServlet?action=page&pageNo=${requestScope.page.pageTotal}">末页</a>
        </c:if>
        共${requestScope.page.pageTotal}页，${requestScope.page.pageTotalCount}条记录
        到第<input value="${param.pageNo}" name="pn" id="pn_input"/>页
        <input id="searchPageBtn"  type="button" value="确定">
    </div>
</div>

<%@include file="/pages/common/footer.jsp" %>
</body>
</html>

抽取分页：
在Page对象中添加url属性以及相应的get 和set方法：

分别在BookServlet和ClientBookServlet中设置url属性值：

分别将index.jsp和book_manager.jsp中出现的相应的地址值替换为${requestScope.page.url}

在/pages/common/下创建page_nav.jsp用于提取分页代码：

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<div id="page_nav">
    <%-- 大于首页才显示--%>
    <c:if test="${requestScope.page.pageNo>1}">
        <a href="${requestScope.page.url}&pageNo=1">首页</a>
        <a href="${requestScope.page.url}&pageNo=${requestScope.page.pageNo-1}">上一页</a>
    </c:if>

    <%--  页码输出的开始--%>
    <c:choose>
        <%-- 情况1：如果总页码<=5,页码的范围是1~总页码 --%>
        <c:when test="${requestScope.page.pageTotal<=5}">
            <c:forEach begin="1" end="${requestScope.page.pageTotal}" var="i">
                <c:if test="${requestScope.page.pageNo==i}">
                    【${i}】
                </c:if>
                <c:if test="${requestScope.page.pageNo!=i}">
                    <a href="${requestScope.page.url}&pageNo=${i}">${i}</a>
                </c:if>
            </c:forEach>
        </c:when>
        <%--情况2：总页码>5 --%>
        <c:when test="${requestScope.page.pageTotal>5}">
            <c:choose>
                <%-- 当前页码为前面3个：页码范围是：1~5--%>
                <c:when test="${requestScope.page.pageNo<=3}">
                    <c:forEach begin="1" end="5" var="i">
                        <c:if test="${requestScope.page.pageNo==i}">
                            【${i}】
                        </c:if>
                        <c:if test="${requestScope.page.pageNo!=i}">
                            <a href="${requestScope.page.url}&pageNo=${i}">${i}</a>
                        </c:if>
                    </c:forEach>
                </c:when>
                <%-- 当前页码为后面3个：页码范围是：当前页码-2~末页--%>
                <c:when test="${requestScope.page.pageNo>=requestScope.page.pageTotal-2}">
                    <c:forEach begin="${requestScope.page.pageNo-4}" end="${requestScope.page.pageTotal}" var="i">
                        <c:if test="${requestScope.page.pageNo==i}">
                            【${i}】
                        </c:if>
                        <c:if test="${requestScope.page.pageNo!=i}">
                            <a href="${requestScope.page.url}&pageNo=${i}">${i}</a>
                        </c:if>
                    </c:forEach>
                </c:when>
                <%-- 当前页码为中间3个：页码范围是：当前页码-2~当前页码+2--%>
                <c:otherwise>
                    <c:forEach begin="${requestScope.page.pageNo-2}" end="${requestScope.page.pageNo+2}" var="i">
                        <c:if test="${requestScope.page.pageNo==i}">
                            【${i}】
                        </c:if>
                        <c:if test="${requestScope.page.pageNo!=i}">
                            <a href="${requestScope.page.url}&pageNo=${i}">${i}</a>
                        </c:if>
                    </c:forEach>
                </c:otherwise>
            </c:choose>
        </c:when>
    </c:choose>
    <%--  页码输出的结束--%>

    <%--  小于末页才显示--%>
    <c:if test="${requestScope.page.pageNo<requestScope.page.pageTotal}">
        <a href="${requestScope.page.url}&pageNo=${requestScope.page.pageNo+1}">下一页</a>
        <a href="${requestScope.page.url}&pageNo=${requestScope.page.pageTotal}">末页</a>
    </c:if>
    共${requestScope.page.pageTotal}页，${requestScope.page.pageTotalCount}条记录
    到第<input value="${param.pageNo}" name="pn" id="pn_input"/>页
    <input id="searchPageBtn" type="button" value="确定">
</div>

在index.jsp和book_mansger.jsp中的分页代码替换成静态包含代码：

<%@include file="/pages/common/page_nav.jsp"%>

6、实现价格区间的搜索功能：

在ClientBookClient中添加pageByPrice()方法用于处理搜索请求：

protected void pageByPrice(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    // 1.获取请求参数 pageNo,pageSize,min,max
    int pageNo = WebUtils.parseInt(req.getParameter("pageNo"),1);
    int pageSize = WebUtils.parseInt(req.getParameter("pageSize"),Page.PAGE_SIZE);
    int min = WebUtils.parseInt(req.getParameter("min"),0);
    int max = WebUtils.parseInt(req.getParameter("max"),Integer.MAX_VALUE);
    // 2.调用bookService.pageByPrice(pageNo,pageSize,min,max) 返回page对象
    Page<Book> page = bookService.pageByPrice(pageNo,pageSize,min,max);
    //设置请求地址 分页时需要传递价格区间
    StringBuilder stringBuilder = new StringBuilder("client/clientBookServlet?action=pageByPrice");
    // 对价格区间进行检查
    if(req.getParameter("min")!=null){
        stringBuilder.append("&min=").append(req.getParameter("min"));
    }
    if(req.getParameter("max")!=null){
        stringBuilder.append("&max=").append(req.getParameter("max"));
    }
    page.setUrl(stringBuilder.toString());

    // 3.将Page对象保存到Request域中
    req.setAttribute("page",page);
    // 4.请求转发到
    req.getRequestDispatcher("/pages/client/index.jsp").forward(req,resp);
}

在BookService中添加pageByPrice(pageNo,pageSize,min,max)方法：

/**
 * 根据价格区间获取page对象
 * @param pageNo
 * @param pageSize
 * @param min
 * @param max
 * @return
 */
Page<Book> pageByPrice(int pageNo, int pageSize, int min, int max);

在BookServiceImpl中实现pageByPrice(pageNo,pageSize,min,max)方法：

@Override
public Page<Book> pageByPrice(int pageNo, int pageSize, int min, int max) {
    Page<Book> bookPage = new Page<>();

    //设置每页显示的数量
    bookPage.setPageSize(pageSize);
    // 设置总记录数
    Integer pageTotalCount = bookDao.queryForPageTotalCountByPrice(min,max);
    bookPage.setPageTotalCount(pageTotalCount);
    // 设置总页码
    Integer pageTotal = pageTotalCount/pageSize;
    if (pageTotalCount % pageSize>0){
        pageTotal++;
    }
    bookPage.setPageTotal(pageTotal);
    // 设置当前页码
    bookPage.setPageNo(pageNo);
    // 设置当页数据
    int begin = (bookPage.getPageNo()-1)*pageSize;
    bookPage.setItems(bookDao.queryForItemsByPrice(begin,pageSize,min,max));
    return bookPage;
}

在BookDao中添加queryForPageTotalCountByPrice(int min, int max)和queryForItemsByPrice(int begin, int pageSize, int min, int max)方法：

 /**
     * 根据价格区间查询总记录数
     * @param min
     * @param max
     * @return
     */
    Integer queryForPageTotalCountByPrice(int min, int max);

    /**
     * 根据价格区间查询所有记录
     * @param begin
     * @param pageSize
     * @param min
     * @param max
     * @return
     */
    List<Book> queryForItemsByPrice(int begin, int pageSize, int min, int max);
}

在BookDaoImpl中实现这两种方法：

@Override
public Integer queryForPageTotalCountByPrice(int min, int max) {
    String sql = "select count(*) from book where price between ? and ?";
    Number count = (Number) queryForSingleValue(sql,min,max);
    return  count.intValue();
}

@Override
public List<Book> queryForItemsByPrice(int begin, int pageSize, int min, int max) {
    String sql = " select `id`, `name`,`author`,`price`,`sales`,`stock`,`img_path` imgPath from book" +
            " where price between ? and ? order by price limit ?,?";
    return queryForList(Book.class,sql,min,max,begin,pageSize);
}

修改index.jsp向服务器提交搜索请求：

<div class="book_cond">
        <form action="client/clientBookServlet" method="get">
            <input type="hidden" name="action" value="pageByPrice"/>
            价格：<input id="min" type="text" name="min" value="${param.min}"> 元 -
            <input id="max" type="text" name="max" value="${param.max}"> 元
            <input type="submit" value="查询"/>
        </form>
</div>

十一、保存用户登录之后的信息

在UserServlet添加保存用户登录信息到Session域中的代码：

在login_success_menu.jsp中 显示用户姓名：

修改index.jsp的菜单显示：

<div>
     <%--  如果用户还没有登录，显示登录和注册菜单 --%>
     <c:if test="${empty sessionScope.user}">
      	<a href="pages/user/login.jsp">登录</a>/
         <a href="pages/user/regist.jsp">注册</a>
     </c:if>

     <%--  如果用户已经登录，则显示登录成功之后用户的信息 --%>
     <c:if test="${not empty sessionScope.user}">
         <span>欢迎<span class="um_span">${sessionScope.user.username}</span>光临书城</span>
         <a href="pages/order/order.jsp">我的订单</a>
         <a href="pages/cart/cart.jsp">购物车</a>
         <a href="pages/manager/manager.jsp">后台管理</a>
         <a href="index.jsp">注销</a>&nbsp;
     </c:if>
</div>

注意：
固定相对路径跳转使用的地址必须是相对路径，否则在进行跳转时Tomcat会创建一个新的Session，造成Session会话信息丢失！

十二、注销登录

在userServlet中添加logout()方法用于处理注销请求：

protected void logout(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    // 1.销毁 Session
    req.getSession().invalidate();
    // 2.重定向到首页
    resp.sendRedirect(req.getContextPath());
}

修改jsp页面的跳转地址：

十三、使用验证码解决表单的重复提交

表单重复提交有三种常见的情况：
一：提交完表单。服务器使用请求转来进行页面跳转。这个时候，用户按下功能键F5，就会发起最后一次的请求。造成表单重复提交问题。解决方法：使用重定向来进行跳转。
二：用户正常提交服务器，但是由于网络延迟等原因，迟迟未收到服务器的响应，这个时候，用户以为提交失败，
就会着急，然后多点了几次提交操作，也会造成表单重复提交。
三：用户正常提交服务器。服务器也没有延迟，但是提交完成后，用户回退浏览器。重新提交。也会造成表单重复
提交。

1.导入谷歌验证码的jar包：kaptcha-2.3.2.jar
2.在web.xml中配置用于访问生成验证码的Servlet程序的地址

<servlet>
        <servlet-name>KaptchaServlet</servlet-name>
        <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
</servlet>
<servlet-mapping>
        <servlet-name>KaptchaServlet</servlet-name>
        <url-pattern>/kaptcha.jpg</url-pattern>
</servlet-mapping>

3.在表单中使用img标签显示验证码图片

<label>验证码：</label>
<input class="itxt" type="text" style="width: 150px;" name="code" id="code"/>
<img id="code_img" alt="" src="kaptcha.jpg" style="float: right; height: 40px; width:120px">
<br/>
<span style="float: right;font-size: 80%">看不清？点击图片刷新</span>
<br/>

4.在服务端中获取生成的验证码并于与客户端发送过来的验证码比较

5.给验证码图片绑定单击事件用于刷新验证码：

// 给验证码图片绑定单击事件
$("#code_img").click(function () {
	// 添加一个随机数避免请求地址相同，因为浏览器缓存造成不刷新
	this.src = "${basePath}kaptcha.jpg?n="+ Math.random();
});

十四、购物车模块

1、创建购物车对象

public class Cart {
    // private Integer totalCount;// 商品总数
    // private BigDecimal totalPrice;// 总商品金额
    private Map<Integer, CartItem> items = new LinkedHashMap<Integer, CartItem>();

    public Integer getTotalCount() {
        Integer totalCount = 0;
        for (Map.Entry<Integer, CartItem> entry : items.entrySet()) {
            totalCount += entry.getValue().getCount();
        }
        return totalCount;
    }

    public BigDecimal getTotalPrice() {
        BigDecimal totalPrice = new BigDecimal(0);
        for (Map.Entry<Integer, CartItem> entry : items.entrySet()) {
            totalPrice = totalPrice.add(entry.getValue().getTotalPrice());
        }
        return totalPrice;
    }

    public Map<Integer, CartItem> getItems() {
        return items;
    }

    public void setItems(Map<Integer, CartItem> items) {
        this.items = items;
    }

    @Override
    public String toString() {
        return "Cart{" +
                "totalCount=" + getTotalCount() +
                ", totalPrice=" + getTotalPrice() +
                ", items=" + items +
                '}';
    }

    // 添加商品项
    public void addItem(CartItem cartItem) {
        // 判断商品是否已经添加
        CartItem item = items.get(cartItem.getId());
        if (item == null) {
            items.put(cartItem.getId(), cartItem);
        } else {
            item.setCount(item.getCount() + 1);
            item.setTotalPrice(item.getPrice().multiply(new BigDecimal(item.getCount())));
        }
    }

    // 删除商品项
    public void deleteItem(Integer id) {
        items.remove(id);
    }

    // 清空购物车
    public void clean() {
        items.clear();
    }

    // 修改商品数量
    public void updateCount(Integer id, Integer count) {
        CartItem item = items.get(id);
        if (item != null) {
            item.setCount(count);
            item.setTotalPrice(item.getPrice().multiply(new BigDecimal(item.getCount())));
        }
    }
}

2、创建购物车商品项

public class CartItem {
    private Integer id;
    private String name;
    private Integer count; // 数量
    private BigDecimal price; // 单价
    private BigDecimal totalPrice;// 商品总价

    public CartItem() {
    }

    public CartItem(Integer id, String name, Integer count, BigDecimal price, BigDecimal totalPrice) {
        this.id = id;
        this.name = name;
        this.count = count;
        this.price = price;
        this.totalPrice = totalPrice;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public BigDecimal getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(BigDecimal totalPrice) {
        this.totalPrice = totalPrice;
    }

    @Override
    public String toString() {
        return "CartItem{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", count=" + count +
                ", price=" + price +
                ", totalPrice=" + totalPrice +
                '}';
    }
}

3、CartServlet用于处理商品的添加、删除、清空和修改数量

public class CartServlet extends BaseServlet {
    private BookService bookService = new BookServiceImpl();
    
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // System.out.println("加入购物车");
        // 获取请求参数  商品编号
        int id = WebUtils.parseInt(req.getParameter("id"),0);
        // 调用bookService.queryBookById(id) 得到图书信息
        Book book = bookService.queryBookById(id);
        // 将图书信息转换位CartItem商品项
        CartItem cartItem = new CartItem(book.getId(),book.getName(),1,book.getPrice(),book.getPrice());
        // 调用cart.add(CartItem)添加至购物车
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        if(cart == null){
            cart = new Cart();
            req.getSession().setAttribute("cart",cart);
        }
        cart.addItem(cartItem);
        // System.out.println(cart);
        // 重定向到原来商品所在的页面
        resp.sendRedirect(req.getHeader("Referer"));
    }

    protected void deleteItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取请求参数 id
        int id = WebUtils.parseInt(req.getParameter("id"),0);
        // 调用cart.deleteItem(id)
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        if(cart != null){
            cart.deleteItem(id);
        }
       resp.sendRedirect(req.getHeader("Referer"));
    }
    
    protected void clear(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取购物车对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        // 调用cart.clear()
        if(cart!=null){
            cart.clear();
        }
        resp.sendRedirect(req.getHeader("Referer"));
    }

    protected void updateCount(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取请求的参数  商品编号  商品数量
        int id = WebUtils.parseInt(req.getParameter("id"),0);
        int count = WebUtils.parseInt(req.getParameter("count"), 1);
        // 获取Cart对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        if(cart!=null){
            // 调用updateCount方法
            cart.updateCount(id,count);
        }
        resp.sendRedirect(req.getHeader("Referer"));
    }
}

4、购物车页面的展示

<script type="text/javascript">
    $(function () {
        // 给删除商品绑定单击事件
        $("a.deleteItem").click(function () {
            return confirm("确定从购物车中删除《"+$(this).parent().parent().find("td:first").text()+"》吗？")
        });
        // 给清空购物车绑定单击事件
        $("#clearCart").click(function(){
           return  confirm("确定清空购物车？");
        });
        // 给修改商品数量绑定失去焦点事件  --- onchange事件判断内容是否改变
        $(".updateCount").change(function(){
            var id = $(this).attr("bookId");
            var count = this.value;
            if(confirm("确定修改商品的数量为 "+count+" 吗？")&&count>0){
                location.href="${PageScope.basePath}cartServlet?action=updateCount&count="+count+"&id="+id;
            }else{
                this.value = this.defaultValue;// 恢复到原来的数据
            }
        });
    })
</script>
<body>
<div id="header">
    <span class="wel_word">购物车</span>
        <%--   静态包含，登录成功之后的菜单    --%>
        <%@include file="/pages/common/login_sucess_menu.jsp" %>
</div>
<div id="main">
    <table>
        <tr>
            <td>商品名称</td>
            <td>数量</td>
            <td>单价</td>
            <td>金额</td>
            <td>操作</td>
        </tr>
        <c:if test="${empty sessionScope.cart.items}">
            <tr>
                <td colspan="5"><a href="index.jsp">当前购物车为空！点击浏览商品</a></td>
            </tr>
        </c:if>

        <c:if test="${not empty sessionScope.cart.items}">
            <%-- 购物车非空才输出--%>
            <c:forEach items="${sessionScope.cart.items}" var="entry">
                <tr>
                    <td>${entry.value.name}</td>
                    <td>
                         <input class="updateCount"
                                style="width: 80px;text-align: center"
                                bookId="${entry.value.id}"
                                type="number" value="${entry.value.count}">
                    </td>
                    <td>${entry.value.price}</td>
                    <td>${entry.value.totalPrice}</td>
                    <td><a class="deleteItem" href="cartServlet?action=deleteItem&id=${entry.value.id}">删除</a></td>
                </tr>
            </c:forEach>
        </c:if>
    </table>
    <c:if test="${not empty sessionScope.cart.items}">
        <div class="cart_info">
            <span class="cart_span">购物车中共有<span class="b_count">${sessionScope.cart.totalCount}</span>件商品</span>
            <span class="cart_span">总金额<span class="b_price">${sessionScope.cart.totalPrice}</span>元</span>
            <span class="cart_span"><a id="clearCart" href="cartServlet?action=clear">清空购物车</a></span>
            <span class="cart_span"><a href="pages/cart/checkout">去结账</a></span>
        </div>
    </c:if>
</div>

5、修改首页

// 添加到购物车
$("button.addToCart").click(function(){
    /**
     * 在事件响应的function函数中  this表示正在响应的dom对象  $(this)表示经过jquery封装后的dom对象
     * @type {jQuery}
     */
    // 判断用户是否登录
    if(${sessionScope.user == null}){
        alert("您还没有登录，请先登录或注册！")
        location.href ="${pageScope.basePath}pages/user/login.jsp";
    } else{
        var bookid =$(this).attr("bookid");// 获取选中元素的属性值
        location.href="${pageScope.basePath}cartServlet?action=addItem&id="+bookid;
    }
   });

<div class="book_add">
    <button bookid="${book.id}" class="addToCart">加入购物车</button>
</div>

6、首页购物车数据回显

在addItem()中将添加的图书信息保存到session域中：

在首页显示需要的信息：

<span>您的购物车中有<span style="color: blue">${sessionScope.cart.totalCount}</span>件商品</span>
<span>
   <%--  购物车为空--%>
    <c:if test="${empty sessionScope.cart.items}">
        <span style="color: red">当前购物车为空~</span>
    </c:if>
    <c:if test="${not empty sessionScope.cart.items}">
           您刚刚将<span style="color: red">${sessionScope.itemName}</span>加入到了购物车中
     </c:if>
</span>

十五、订单模块

1、创建Order 与OrderItem对象

public class Order {
    private String orderId;// 订单号
    private Date createTime;// 下单时间
    private BigDecimal price;// 订单价格
    private Integer status = 0;// 0 未发货  1 已发货 2 已签收
    private Integer userId;

    public Order() {
    }

    public Order(String orderId, Date createTime, BigDecimal price, Integer status, Integer userId) {
        this.orderId = orderId;
        this.createTime = createTime;
        this.price = price;
        this.status = status;
        this.userId = userId;
    }

    public String getOrderId() {
        return orderId;
    }

    public void setOrderId(String orderId) {
        this.orderId = orderId;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    @Override
    public String toString() {
        return "Order{" +
                "orderId=" + orderId +
                ", createTime=" + createTime +
                ", price=" + price +
                ", status=" + status +
                ", userId=" + userId +
                '}';
    }
}

public class OrderItem {
    private Integer id;// 商品编号
    private String name;// 商品名称
    private Integer count;// 商品数量
    private BigDecimal price;// 商品总价格
    private BigDecimal totalPrice;// 商品总价格
    private String orderId;// 订单号

    public OrderItem() {
    }

    public OrderItem(Integer id, String name, Integer count, BigDecimal price, BigDecimal totalPrice, String orderId) {
        this.id = id;
        this.name = name;
        this.count = count;
        this.price = price;
        this.totalPrice = totalPrice;
        this.orderId = orderId;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }

    public BigDecimal getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(BigDecimal totalPrice) {
        this.totalPrice = totalPrice;
    }

    public String getOrderId() {
        return orderId;
    }

    public void setOrderId(String orderId) {
        this.orderId = orderId;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "OrderItem{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", count=" + count +
                ", price=" + price +
                ", totalPrice=" + totalPrice +
                ", orderId=" + orderId +
                '}';
    }
}

2、创建OrderDao接口并实现接口中的方法

public interface OrderDao {
    /**
     * 保存订单
     * @param order
     * @return
     */
    public int saveOrder(Order order);

    /**
     * 查询全部订单
     * @return
     */
    public List<Order> queryOrders();

    /**
     * 修改订单状态
     * @param orderId
     * @param Status
     * @return
     */
    public int changeOrderStatus(String orderId,Integer status);

    /**
     * 根据用户编号查看订单信息
     * @param UserId
     * @return
     */
    public List<Order> queryOrderByUserId(Integer userId);
}

public class OrderDaoImpl extends BaseDao implements OrderDao {
    @Override
    public int saveOrder(Order order) {
        String sql = "insert into bookorder(`order_id`,`create_time`,`price`,`status`,`user_id`)values(?,?,?,?,?)";
        return update(sql,order.getOrderId(),order.getCreateTime(),order.getPrice(),order.getStatus(),order.getUserId());
    }

    @Override
    public List<Order> queryOrders() {
        String sql = "select `order_id` orderId ,`create_time` createTime,`price` ,`status`,`user_id` userId from bookorder";
        return queryForList(Order.class,sql);
    }

    @Override
    public int changeOrderStatus(String orderId, Integer status) {
        String sql = "update bookorder set status = ? where order_id = ?";
        return update(sql,status,orderId);
    }

    @Override
    public List<Order> queryOrderByUserId(Integer userId) {
        String sql = "select `order_id` orderId ,`create_time` createTime,`price` ,`status`,`user_id` userId from bookorder where user_id=?";
        return queryForList(Order.class,sql,userId);
    }
}

3、创建 OrderItemDao接口并实现其方法

public interface OrderItemDao {
    /**
     * 保存订单项
     * @param item
     * @return
     */
    public int saveOrderItem(OrderItem item);

    /**
     * 更具订单号查询订单详情
     * @param orderId
     * @return
     */
    public OrderItem queryOrderItemsByOrderId(String orderId);
}

public class OrderItemDaoImpl extends BaseDao implements OrderItemDao {
    @Override
    public int saveOrderItem(OrderItem item) {
        String sql = "insert into bookorder_item(`name`,`count`,`price`,`totalprice`,`order_id`)values(?,?,?,?,?)";
        return update(sql,item.getName(),item.getCount(),item.getPrice(),item.getTotalPrice(),item.getOrderId());
    }

    @Override
    public OrderItem queryOrderItemsByOrderId(String orderId) {
        String sql = "select `name`,`count`,`price`,`totalprice` totalPrice,`order_id` orderId from bookorder_item where order_id = ?";
        return queryForOne(OrderItem.class,sql,orderId);
    }
}

4、创建OrderService并实现其中的方法

public interface OrderService {
    /**
     * 生成订单
     * @param cart
     * @param userId
     * @return 订单号
     */
    public String createOrder(Cart cart,Integer userId);

    /**
     * 查询全部订单
     * @return
     */
    public List<Order> showAllOrder();

    /**
     * 发货
     * @param orderId
     */
    public void sendOrder(String orderId);

    /**
     * 查看订单详情
     * @param orderId
     * @return
     */
    public OrderItem showOrderDetailById(String orderId);

    /**
     * 用户查看订单
     * @param userId
     * @return
     */
    public List<Order> showMyOrder(Integer userId);

    /**
     * 签收订单
     * @param orderId
     */
    public void receiverOrder(String orderId);

}

public class OrderServiceImpl implements OrderService {

    private OrderDao orderDao = new OrderDaoImpl();
    private OrderItemDao orderItemDao = new OrderItemDaoImpl();
    private BookDao bookDao = new BookDaoImpl();

    @Override
    public String createOrder(Cart cart, Integer userId) {
        // 订单号唯一
        String orderId = System.currentTimeMillis() + "" + userId;
        // 创建一个订单对象
        Order order = new Order(orderId, new Date(), cart.getTotalPrice(), 0, userId);
        // 保存 订单到数据库
        orderDao.saveOrder(order);
        // 保存订单项
        // 创建订单项
        // 遍历购物车中的每一个商品项转换为订单商品项
        for (Map.Entry<Integer, CartItem> entry : cart.getItems().entrySet()) {
            CartItem cartItem = entry.getValue();
            OrderItem orderItem = new OrderItem(null, cartItem.getName(), cartItem.getCount(), cartItem.getPrice(), cartItem.getTotalPrice(), orderId);
            orderItemDao.saveOrderItem(orderItem);

            // 修改图书库存和销量
            // 获取book对象
            Book book = bookDao.queryBookById(cartItem.getId());
            book.setSales(book.getSales() + cartItem.getCount());
            book.setStock(book.getStock() - cartItem.getCount());
            bookDao.updateBook(book);
        }
        // 清空购物车
        cart.clear();
        return orderId;
    }

    @Override
    public List<Order> showAllOrder() {
        return orderDao.queryOrders();
    }

    @Override
    public void sendOrder(String orderId) {
        orderDao.changeOrderStatus(orderId,1);
    }

    @Override
    public OrderItem showOrderDetailById(String orderId) {
        return orderItemDao.queryOrderItemsByOrderId(orderId);
    }

    @Override
    public List<Order> showMyOrder(Integer userId) {
        return orderDao.queryOrderByUserId(userId);
    }

    @Override
    public void receiverOrder(String orderId) {
        orderDao.changeOrderStatus(orderId,2);
    }
}

5、创建OrderServlet并添加相应的功能

public class OrderServlet extends BaseServlet {

    private OrderService orderService = new OrderServiceImpl();
    /**
     * 生成订单
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void createOrder(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取Cart对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        // 获取userId
        User user = (User) req.getSession().getAttribute("user");
        Integer userId = user.getId();
        // 调用orderService
        String orderId = orderService.createOrder(cart, userId);
        req.getSession().setAttribute("orderId",orderId);
        // 重定向结算成功页面
        resp.sendRedirect(req.getContextPath()+"/pages/cart/checkout.jsp");
    }

    /**
     * 查询我的订单
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void showMyOrders(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取userId
        User user = (User) req.getSession().getAttribute("user");
        Integer userId = user.getId();
        // 得到order对象
        List<Order> orders= orderService.showMyOrder(userId);
        // 保存至request中
        req.setAttribute("orders",orders);
        // 请求转发到我的订单页面
        req.getRequestDispatcher("/pages/order/order.jsp").forward(req,resp);
    }

    /**
     * 查看商品详情
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void showOrderDetail(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取orderId
        String orderId = req.getParameter("orderId");
        // System.out.println(orderId);
        // 创建OrderItem对象
        // 调用oderService.showOrderDetailById()
        OrderItem orderItem = orderService.showOrderDetailById(orderId);
        req.setAttribute("orderItem",orderItem);
        req.getRequestDispatcher("/pages/order/order_detail.jsp").forward(req,resp);
    }

    /**
     * 显示所有订单
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void showAllOrders(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        List<Order> allOrders =  orderService.showAllOrder();
        req.setAttribute("allOrders",allOrders);
        req.getRequestDispatcher("/pages/manager/order_manager.jsp").forward(req,resp);
    }

    /**
     * 发货
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void sendOrder(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取orderId
        String orderId = req.getParameter("orderId");
        orderService.sendOrder(orderId);
        resp.sendRedirect(req.getContextPath()+"/orderServlet?action=showAllOrders");
    }

    /**
     * 确认收货
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void receiverOrder(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取orderId
        String orderId = req.getParameter("orderId");
        orderService.receiverOrder(orderId);
        resp.sendRedirect(req.getContextPath()+"/orderServlet?action=showMyOrders");
    }
}

5、调整jsp页面

1.修改购物车页面中去结算的跳转地址

2.在order.jsp中显示当前用户的订单信息

<table>
   <tr>
      <td>日期</td>
      <td>金额</td>
      <td>状态</td>
      <td>详情</td>
      <td>确认收货</td>
   </tr>
   <c:if test="${not empty requestScope.orders}">
      <c:forEach items="${requestScope.orders}" var="order">
         <tr>
            <td>${order.createTime}</td>
            <td>${order.price}</td>
            <td>
               <c:choose>
                  <c:when test="${order.status==0}">未发货</c:when>
                  <c:when test="${order.status==1}">已发货</c:when>
                  <c:otherwise>已签收</c:otherwise>
               </c:choose>
            </td>
            <td><a href="orderServlet?action=showOrderDetail&orderId=${order.orderId}">查看详情</a></td>
            <td><c:choose>
               <c:when test="${order.status==0}"><span style="color: red">还没有发货哦~</span></c:when>
               <c:when test="${order.status==1}"><a href="orderServlet?action=receiverOrder&orderId=${order.orderId}">确认收货</a></c:when>
               <c:otherwise><span style="color: red">已经签收了~</span></c:otherwise>
            </c:choose>
            </td>
         </tr>
      </c:forEach>
   </c:if>
   <c:if test="${empty requestScope.orders}">
      <td colspan="4"><a href="pages/cart/cart.jsp">您暂时没有订单，快去购物车下单吧~</a></td>
   </c:if>
</table>

4.在order_detail.jsp中显示订单的详细信息

<table>
    <tr>
        <td>商品名称</td>
        <td>数量</td>
        <td>单价</td>
        <td>总价</td>
        <td>订单号</td>
    </tr>
    <tr>
        <td>${requestScope.orderItem.name}</td>
        <td>${requestScope.orderItem.count}</td>
        <td>${requestScope.orderItem.price}</td>
        <td>${requestScope.orderItem.totalPrice}</td>
        <td>${requestScope.orderItem.orderId}</td>
    </tr>
</table>

5.修改首页的后台管理中订单管理的跳转地址

6.在订单管理中显示所有的订单信息

<table>
    <tr>
        <td>日期</td>
        <td>金额</td>
        <td>详情</td>
        <td>状态</td>
        <td>发货</td>
    </tr>
    <c:if test="${not empty requestScope.allOrders}">
        <c:forEach items="${requestScope.allOrders}" var="order">
            <tr>
                <td>${order.createTime}</td>
                <td>${order.price}</td>
                <td><a href="orderServlet?action=showOrderDetail&orderId=${order.orderId}">查看详情</a></td>
                <td>
                    <c:choose>
                        <c:when test="${order.status==0}">未发货</c:when>
                        <c:when test="${order.status==1}">已发货</c:when>
                        <c:otherwise>已签收</c:otherwise>
                    </c:choose>
                </td>
                <td>
                    <c:choose>
                        <c:when test="${order.status==0}">
                            <a href="orderServlet?action=sendOrder&orderId=${order.orderId}">发货</a>
                        </c:when>
                        <c:when test="${order.status==1}"><span style="color: red">已经发货了~</span></c:when>
                        <c:otherwise><span style="color: red">已经签收了~</span></c:otherwise>
                    </c:choose>
                </td>
            </tr>
        </c:forEach>
    </c:if>
    <c:if test="${empty requestScope.allOrders}">
        <td colspan="5">暂时没有订单</td>
    </c:if>
</table>

十六、使用Filter实现权限检查

package com.bookmall.filter;

public class ManagerFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        User user = (User) httpServletRequest.getSession().getAttribute("user");
        if(user.getStatus()!=1){
            httpServletRequest.getRequestDispatcher("/pages/user/login.jsp").forward(request,response);
        }else{
            chain.doFilter(request,response);
        }
    }

    @Override
    public void destroy() {

    }
}

<filter>
    <filter-name>ManagerFilter</filter-name>
    <filter-class>com.bookmall.filter.ManagerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>ManagerFilter</filter-name>
    <url-pattern>/pages/manager/*</url-pattern>
    <url-pattern>/manager/bookServlet</url-pattern>
</filter-mapping>

十七、使用Filter和TheadLocal组合管理事务

修改JdbcUtils：
创建一个ThreadLocal对象，用于将获取的连接与当前线程关联：

修改getConnection()：

public static Connection getConnection() {
    Connection conn = conns.get();
    if (conn == null) {
        try {
            conn = dataSource.getConnection();// 从数据库连接池中获取连接
            conns.set(conn);// 将连接保存到ThreadLocal对象中，供后面的jdbc操作使用，保证执行事务时是同一个连接
            conn.setAutoCommit(false);// 设置为不自动提交事务
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    return conn;
}

添加提交并关闭连接的方法以及回滚并关闭连接的方法：

 /**
 * 提交事务并关闭连接
 */
public static void commitAndClose(){
    Connection conn = conns.get();
    if(conn!=null){
        try {
            conn.commit();// 提交事务
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        } finally {
            try {
                conn.close();// 关闭连接
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }
    // 移除线程
    conns.remove(); 
}

/**
 * 回滚事务并关闭连接
 */
public static void rollbackAndClose(){
    Connection conn = conns.get();
    if(conn !=null){
        try {
            conn.rollback();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        } finally {
            try {
                conn.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }
}

修改BaseDao,BaseServlet：
1、将所有方法中的关闭连接操作删除，用于保证所用操作都使用同一个连接；
2、在每个方法中都添加抛出异常的语句，提供给执行相应操作的Servlet程序捕获，用于回滚。
使用Filter过滤器为所用的Service方法添加try-catch:

package com.bookmall.filter;

public class TransactionFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        try {
            chain.doFilter(request,response);
            // 提交事务
            JdbcUtils.commitAndClose();
        } catch (Exception e) {
            // 回滚事务
            JdbcUtils.rollbackAndClose();
            // 将异常抛给服务器
            throw new RuntimeException(e);
        }
    }

    @Override
    public void destroy() {

    }
}

<filter>
    <filter-name>TransactionFilter</filter-name>
    <filter-class>com.bookmall.filter.TransactionFilter</filter-class>
</filter>
<filter-mapping>
   <filter-name>TransactionFilter</filter-name>
    <!--  当前工程下的所有请求 -->
    <url-pattern>/*</url-pattern>
</filter-mapping>

将所有异常同一交给Tomcat，让Tomcat展示友好的错误信息页面：
配置web.xml

<!-- 配置服务器出错后，自动跳转的页面-->
<error-page>
    <!--   错误类型-->
    <error-code>404</error-code>
    <!--  要跳转去的页面路径-->
    <location>/pages/error/error404.jsp</location>
</error-page>
<error-page>
    <error-code>500</error-code>
    <location>/pages/error/error500.jsp</location>
</error-page>

十八、使用Ajax判断用户名是否可用

// 给用户名输入框绑定失去焦点事件
$("#username").blur(function () {
    // 获取用户名
    var username = this.value;
    $.getJSON(
        "${pageScope.basePath}userServlet",
        "action=ajaxExistUsername&username=" + username,
        function (data) {
            if (data.existUsername) {
                $("span.errorMsg").css({color:"#dd0000"});
                $("span.errorMsg").text("用户名已存在！");
            } else {
                $("span.errorMsg").css({color:"#00dd00"});
                $("span.errorMsg").text("用户名可用~");
            }
        });
});

在UserServlet中添加ajaxExisUsername()

/**
 * 验证用户名是否已经注册
 * @param req
 * @param resp
 * @throws ServletException
 * @throws IOException
 */
protected void ajaxExistUsername(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
    // 获取请求参数
    String username = req.getParameter("username");
    // 调用userService
    boolean existUsername = userService.existUsername(username);
    // 把返回的结果封装成Map对象
    Map<String,Object> resultMap = new HashMap<String, Object>();
    resultMap.put("existUsername",existUsername);
    // 将Map对象转换为json字符串
    Gson gson = new Gson();
    String json = gson.toJson(resultMap);
    resp.getWriter().write(json);
}

十九、使用Ajax修改把商品添加到购物车

/**
 * 使用Ajax添加图书到购物车
 * @param req
 * @param resp
 * @throws ServletException
 * @throws IOException
 */
protected void ajaxAddItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    // System.out.println("加入购物车");
    // 获取请求参数  商品编号
    int id = WebUtils.parseInt(req.getParameter("id"),0);
    // 调用bookService.queryBookById(id) 得到图书信息
    Book book = bookService.queryBookById(id);
    // 将图书信息转换为CartItem商品项
    CartItem cartItem = new CartItem(book.getId(),book.getName(),1,book.getPrice(),book.getPrice());
    // 调用cart.add(CartItem)添加至购物车
    Cart cart = (Cart) req.getSession().getAttribute("cart");
    if(cart == null){
        cart = new Cart();
        req.getSession().setAttribute("cart",cart);
    }
    cart.addItem(cartItem);
    // 将添加的商品添加到session域中
    req.getSession().setAttribute("itemName",cartItem.getName());
    // 将需要在页面刷新的信息封装到Map中
    Map<String,Object> resultMap = new HashMap<String, Object>();
    // 购物车中总的商品数量
    resultMap.put("totalCount",cart.getTotalCount());
    // 最后一个添加到购物车的商品名称
    resultMap.put("lastName",cartItem.getName());
    // 将Map转换为json字符串
    Gson gson = new Gson();
    String json = gson.toJson(resultMap);
    // 回传给客户端
    resp.getWriter().write(json);
}

var bookid = $(this).attr("bookid");// 获取选中元素的属性值
// location.href="${pageScope.basePath}cartServlet?action=addItem&id="+bookid;
// 使用ajax发送请求
$.getJSON(
    "${pageScope.basePath}cartServlet",
    "action=ajaxAddItem&id=" + bookid,
    function (data) {
        $("#cartTotalCount").text(data.totalCount);
        $("#cartlastName").text(data.lastName);
    })

<span>您的购物车中有<span id="cartTotalCount" style="color:red">${sessionScope.cart.totalCount}</span>件商品</span>
<span>
    您刚刚将<span id="cartlastName"style="color:red">${sessionScope.itemName}</span>加入到了购物车中
</span>