大数据正式20

朴灿烈づ我的快乐病毒、 2022-06-04 08:27 365阅读 0赞

# 大数据正式20 #

### JavaEE开发模式 ###

*  为什么要有JavaEE开发模式
    
    1.  之前的代码混在一起太乱
    2.  项目越来越大，代码结构太差
    3.  之前设计分层不清，不便于维护和扩展
    4.  。。。。。
 *  发展阶段一
    
     *  Servlet：
        
         *  本质上是java代码，所以非常便于处理逻辑，但是不擅长输出界面
     *  jsp：
        
         *  看起来像HTML，但是内部可以写java代码，是一种动态web资源开发技术，非常便于编写界面，嵌入的代码也可以用来处理部分逻辑。但是这样做的话，jsp又产生了大量的代码，又难以维护和扩展
     *  javaBean+jsp
        
         *  这种开发模式下，jsp负责接收请求、资源调度、展示页面，javaBean负责数据的封装、数据处理、数据的持久化等操作
         *  ![GPWVdPB.png][]
         *  这种模式不可避免的又在jsp里写java代码
 *  发展阶段二
    
     *  Servlet+JavaBean+Jsp
        
         *  Servlet：资源调度
         *  JavaBean：封装数据、处理数据、持久化数据
         *  Jsp：展示数据
         *  ![lDFrjsm.png][]
         *  MVC设计思想：
            
             *  M：Model，模型【封装数据、处理数据】
             *  V：View，视图【和用户交互】
             *  C：Controller，控制器【控制程序的流转】
             *  尽量做到：这三个部分尽量相互独立，互不影响；这样可以让软件结构清晰，模块之间互不干扰，有利于软件的设计、开发和维护
 *  发展阶段三
    
     *  模块组装
        
         *  ![cvfp7G3.png][]
     *  mvc架构
        
         *  ![R1E90UH.png][]
     *  JavaEE经典的三层架构
        
         *  ![dV6Ce5A.png][]
         *  分层的目的：
            
            1.  代码更加具有优良的结构，便于开发和调试
            2.  便于层与层的代码复用，减少代码冗余
            3.  在更改模块时可以不影响其他模块的使用，实现模块的复用
                
                1.  mysql->oracle【只需写个新的实现类】
                2.  web->android【service和dao层不需要修改】
         *  三层独立：不要将特有的对象作为参数传给其它层，否则形成入侵，耦合度形成并变高，这种耦合是有害的，应该尽量避免，实现高内聚，低耦合
         *  解耦的实现
            
            1.  不要互换传递层特有的对象，尽量避免。
            2.  但是再小心，层与层早晚要发生关系的，此时需要将耦合管理起来
                
                1.  Spring框架
                2.  接口+配置文件+工厂模式
                    
                    #  #
                    
                        package com.easymall.factory;
                        
                        import java.io.File;
                        import java.io.FileInputStream;
                        import java.io.FileNotFoundException;
                        import java.io.IOException;
                        import java.util.Properties;
                        
                        public class BasicFactory {
                        
                            private static BasicFactory factory = new BasicFactory();
                            private static Properties prop = null;
                        
                            static {
                                prop = new Properties();
                                try {
                                    prop.load(new FileInputStream(new File(BasicFactory.class
                                            .getClassLoader().getResource("config.properties")
                                            .getPath())));
                                } catch (FileNotFoundException e) {
                                    e.printStackTrace();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            }
                        
                            private BasicFactory() {
                                super();
                            }
                        
                            public static BasicFactory getFactory() {
                                return factory;
                            }
                        
                            @SuppressWarnings("unchecked")
                            public <T> T getObj(Class<T> c) {
                                System.out.println(prop);
                                String name = prop.getProperty(c.getSimpleName());
                                System.out.println(name);
                                Class<?> basic = null;
                                Object obj = null;
                                try {
                                    basic = Class.forName(name);
                                    obj = basic.newInstance();
                                } catch (ClassNotFoundException e) {
                                    e.printStackTrace();
                                } catch (InstantiationException e) {
                                    e.printStackTrace();
                                } catch (IllegalAccessException e) {
                                    e.printStackTrace();
                                }
                                return (T) obj;
                            }
                        }

### javaEE三层架构流程演示 ###

*  注册逻辑
    
     *  ![66lix6m.png][]

### 软件分层换底层 ###

*  可能影响的原因
    
     *  HttpServlet的传递，改换成Android就蒙圈了
     *  各层之间的对象引用写死
 *  只需改相应的层即可
 *  详细看代码重构中的具体结构与相应的代码

### EasyMall代码重构 ###

*  之前的结构
    
     *  ![ktfBzbA.png][]
 *  重构之后的结构
    
     *  ![qntiQX2.png][]

### 重构具体代码 ###

*  com.easymall.dao
    
     *  UserDao
        
        #  #
        
            package com.easymall.dao;
            
            import com.easymall.domain.User;
            
            public interface UserDao {
            
                /**
                 * 通过用户名查询数据库中是否有该数据记录
                 * 
                 * @param user
                 * @return 是否存在该用户名对应的数据记录
                 */
                public boolean findUserByUserName(User user);
            
                /**
                 * 添加用户信息
                 * 
                 * @param user用户信息实体
                 * @return void
                 */
                public void addUser(User user);
            
                /**
                 * 通过账号和密码来查询数据库是否有此账号
                 * 
                 * @param username
                 * @param password
                 * @return 返回通数据库是否有此账号和密码对应的记录
                 */
                public boolean findUserByNameAndPass(String username, String password);
            
            }
     *  UserDaoImpl
        
        #  #
        
            package com.easymall.dao;
            
            import java.sql.Connection;
            import java.sql.PreparedStatement;
            import java.sql.ResultSet;
            import java.sql.SQLException;
            
            import com.easymall.domain.User;
            import com.easymall.utils.MySqlUtils;
            
            public class UserDaoImpl implements UserDao {
                Connection conn = null;
                PreparedStatement stat = null;
                ResultSet rs = null;
            
                public boolean findUserByUserName(User user) {
                    try {
                        conn = MySqlUtils.getConn();
                        stat = conn.prepareStatement("select * from user where username=?");
                        stat.setString(1, user.getUsername());
                        rs = stat.executeQuery();
                        return rs.next();
                    } catch (SQLException e) {
                        return false;
                    } finally {
                        MySqlUtils.close(conn, stat, rs);
                    }
                }
            
                public void addUser(User user) {
            
                    conn = MySqlUtils.getConn();
                    try {
                        stat = conn.prepareStatement("insert into user values(?,?,?,?)");
                        stat.setString(1, user.getUsername());
                        stat.setString(2, user.getPassword());
                        stat.setString(3, user.getNickname());
                        stat.setString(4, user.getEmail());
                        stat.executeUpdate();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    } finally {
                        MySqlUtils.close(conn, stat, rs);
                    }
            
                }
            
                public boolean findUserByNameAndPass(String username, String password) {
                    conn = MySqlUtils.getConn();
                    try {
                        stat = conn
                                .prepareStatement("select * from user where username=? and password=?");
                        stat.setString(1, username);
                        stat.setString(2, password);
                        rs = stat.executeQuery();
                        return rs.next();
                    } catch (SQLException e) {
                        return false;
                    } finally {
                        MySqlUtils.close(conn, stat, rs);
                    }
                }
            
            }
 *  com.easymall.domain
    
     *  User
        
        #  #
        
            package com.easymall.domain;
            
            /**
             * 注册用户
             * 
             * @author Administrator
             * 
             */
            public class User {
                private int id;
                private String username;
                private String password;
                private String nickname;
                private String email;
            
                public User() {
                    super();
                }
            
                public User(int id, String username, String password, String nickname,
                        String email) {
                    super();
                    this.id = id;
                    this.username = username;
                    this.password = password;
                    this.nickname = nickname;
                    this.email = email;
                }
            
                public int getId() {
                    return id;
                }
            
                public void setId(int 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 getNickname() {
                    return nickname;
                }
            
                public void setNickname(String nickname) {
                    this.nickname = nickname;
                }
            
                public String getEmail() {
                    return email;
                }
            
                public void setEmail(String email) {
                    this.email = email;
                }
            
            }
 *  com.easymall.exception
    
     *  MsgException
        
        #  #
        
            package com.easymall.exception;
            
            @SuppressWarnings("serial")
            public class MsgException extends RuntimeException {
                public MsgException() {
                }
            
                public MsgException(String msg) {
                    super(msg);
                }
            }
 *  com.easymall.factory
    
     *  BasicFactory
        
        #  #
        
            package com.easymall.factory;
            
            import java.io.File;
            import java.io.FileInputStream;
            import java.io.FileNotFoundException;
            import java.io.IOException;
            import java.util.Properties;
            
            public class BasicFactory {
            
                private static BasicFactory factory = new BasicFactory();
                private static Properties prop = null;
            
                static {
                    prop = new Properties();
                    try {
                        prop.load(new FileInputStream(new File(BasicFactory.class
                                .getClassLoader().getResource("config.properties")
                                .getPath())));
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            
                private BasicFactory() {
                    super();
                }
            
                public static BasicFactory getFactory() {
                    return factory;
                }
            
                @SuppressWarnings("unchecked")
                public <T> T getObj(Class<T> c) {
                    System.out.println(prop);
                    String name = prop.getProperty(c.getSimpleName());
                    System.out.println(name);
                    Class<?> basic = null;
                    Object obj = null;
                    try {
                        basic = Class.forName(name);
                        obj = basic.newInstance();
                    } catch (ClassNotFoundException e) {
                        e.printStackTrace();
                    } catch (InstantiationException e) {
                        e.printStackTrace();
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                    return (T) obj;
                }
            }
 *  com.easymall.service
    
     *  UserService
        
        #  #
        
            package com.easymall.service;
            
            import com.easymall.domain.User;
            import com.easymall.exception.MsgException;
            
            public interface UserService {
                /**
                 * 注册用户
                 * 
                 * @param user封装了要注册用户的数据
                 * @throws 注册中用户信息有误则抛出异常
                 */
                void regist(User user) throws MsgException;
            
                /**
                 * 查询账号是否重复
                 * 
                 * @param 用户实体
                 * @return 返回数据库中是否有此用户名
                 */
                boolean checkHasUsername(User user);
            
                /**
                 * 
                 * 检查用户名和密码
                 * 
                 * @param username
                 * @param password
                 * @return 返回是否存在该账户和密码
                 */
                boolean checkUsernameAndPassord(String username, String password);
            
                /**
                 * 添加一名用户
                 * 
                 * @param user
                 * @return void
                 */
                void addUser(User user);
            
            }
     *  UserServiceImpl
        
        #  #
        
            package com.easymall.service;
            
            import com.easymall.dao.UserDao;
            import com.easymall.domain.User;
            import com.easymall.exception.MsgException;
            import com.easymall.factory.BasicFactory;
            
            public class UserServiceImpl implements UserService {
                UserDao ud = BasicFactory.getFactory().getObj(UserDao.class);
            
                public void regist(User user) throws MsgException {
                    boolean hasUser = ud.findUserByUserName(user);
                    // 如果用户名重复则抛出异常
                    if (hasUser) {
                        throw new MsgException("该账号已经存在！");
                    } else {
                        // 如果用户名不重复则向数据库写入信息
                        ud.addUser(user);
                    }
                }
            
                public boolean checkHasUsername(User user) {
                    // 找到返回true，找不到返回false
                    return ud.findUserByUserName(user);
                }
            
                public boolean checkUsernameAndPassord(String username, String password) {
                    return ud.findUserByNameAndPass(username, password);
                }
            
                public void addUser(User user) {
                    ud.addUser(user);
                }
            
            }
 *  com.easymall.utils
    
     *  MySqlUtils
        
        #  #
        
            package com.easymall.utils;
            
            import java.sql.Connection;
            import java.sql.ResultSet;
            import java.sql.SQLException;
            import java.sql.Statement;
            
            import com.mchange.v2.c3p0.ComboPooledDataSource;
            
            public class MySqlUtils {
                // 创建数据库连接池--数据连接池只允许有一个
                private static ComboPooledDataSource cpds = new ComboPooledDataSource();
            
                // 将构造函数私有化，不允许创建该实例
                private MySqlUtils() {
                    super();
                }
            
                // 获取连接
                public static Connection getConn() {
                    Connection conn = null;
                    try {
                        conn = cpds.getConnection();
                    } catch (SQLException e) {
                        // 没有获得数据库连接的异常处理[有待详细处理]
                        throw new RuntimeException(e);
                    }
                    return conn;
                }
            
                // 关闭资源
                public static void close(Connection conn, Statement stat, ResultSet rs) {
                    if (conn != null) {
                        try {
                            conn.close();
                        } catch (SQLException e) {
                            e.printStackTrace();
                        } finally {
                            conn = null;
                        }
                    }
                    if (stat != null) {
                        try {
                            stat.close();
                        } catch (SQLException e) {
                            e.printStackTrace();
                        } finally {
                            stat = null;
                        }
                    }
                    if (rs != null) {
                        try {
                            rs.close();
                        } catch (SQLException e) {
                            e.printStackTrace();
                        } finally {
                            rs = null;
                        }
                    }
                }
            
            }
 *  com.easymall.web
    
     *  CheckHasUsernameServlet
        
        #  #
        
            package com.easymall.web;
            
            import java.io.IOException;
            
            import javax.servlet.ServletException;
            import javax.servlet.http.HttpServlet;
            import javax.servlet.http.HttpServletRequest;
            import javax.servlet.http.HttpServletResponse;
            
            import com.easymall.domain.User;
            import com.easymall.factory.BasicFactory;
            import com.easymall.service.UserService;
            
            @SuppressWarnings("serial")
            public class CheckHasUsernameServlet extends HttpServlet {
                private boolean hasUser = false;
                UserService userService = BasicFactory.getFactory().getObj(
                        UserService.class);
            
                protected void doGet(HttpServletRequest req, HttpServletResponse resp)
                        throws ServletException, IOException {
                    try {
                        // 获取用户名并解决乱码
                        String username = new String(req.getParameter("username").getBytes(
                                "iso8859-1"), "utf-8");
                        // 查询数据库中是否有此用户
                        User user = new User(-1, username, null, null, null);
                        hasUser = userService.checkHasUsername(user);
                    } catch (Exception e) {
                        throw new RuntimeException(e);
                    }
                    // 返回json格式的数据
                    System.out.println(hasUser);
                    resp.getWriter().write("{\"hasUser\":" + hasUser + "}");
                }
            
                protected void doPost(HttpServletRequest req, HttpServletResponse resp)
                        throws ServletException, IOException {
                    this.doGet(req, resp);
                }
            
            }
     *  LoginServlet
        
        #  #
        
            package com.easymall.web;
            
            import java.io.IOException;
            import java.net.URLEncoder;
            
            import javax.servlet.ServletException;
            import javax.servlet.http.Cookie;
            import javax.servlet.http.HttpServlet;
            import javax.servlet.http.HttpServletRequest;
            import javax.servlet.http.HttpServletResponse;
            import javax.servlet.http.HttpSession;
            
            import com.easymall.factory.BasicFactory;
            import com.easymall.service.UserService;
            
            @SuppressWarnings("serial")
            public class LoginServlet extends HttpServlet {
                // 处理逻辑
                UserService us = BasicFactory.getFactory().getObj(
                        UserService.class);
            
                public void doGet(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                    this.doPost(request, response);
                }
            
                public void doPost(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                    // 解决乱码
                    request.setCharacterEncoding("utf-8");
                    response.setCharacterEncoding("utf-8");
                    response.setContentType("text/html;charset=utf-8");
            
                    // 获取用户名和密码
                    String username = request.getParameter("username") == null ? ""
                            : request.getParameter("username");
                    String password = request.getParameter("password") == null ? ""
                            : request.getParameter("password");
                    // 处理记住用户名的逻辑
                    if ("true".equals(request.getParameter("remname"))) {
                        System.out.println("sdfg");
                        Cookie cookie = new Cookie("remname", URLEncoder.encode(username,
                                "utf-8"));
                        cookie.setMaxAge(60 * 60 * 24 * 30);
                        cookie.setPath(request.getContextPath());
                        response.addCookie(cookie);
                    } else {// 不保存--删除Cookie
                        Cookie cookie = new Cookie("remname", "");
                        cookie.setMaxAge(0);
                        cookie.setPath(request.getContextPath());
                        response.addCookie(cookie);
                    }
                    // 检查用户名和密码
                    if (us.checkUsernameAndPassord(username, password)) {
                        // 获取session
                        HttpSession session = request.getSession();
                        // 在session中加入相应的标记
                        session.setAttribute("username", username);
                        // 回到主页
                        response.getWriter().write("登录成功！正在跳转。。。");
                        response.setHeader("refresh", "2;url=" + request.getContextPath()
                                + "/index.jsp");
                    } else {
                        response.addHeader("refresh", "0;url=" + request.getContextPath()
                                + "/login.jsp?msg=" + URLEncoder.encode("账号密码错误！", "utf-8"));
                    }
                }
            }
     *  LogOutServlet
        
        #  #
        
            package com.easymall.web;
            
            import java.io.IOException;
            
            import javax.servlet.ServletException;
            import javax.servlet.http.HttpServlet;
            import javax.servlet.http.HttpServletRequest;
            import javax.servlet.http.HttpServletResponse;
            
            @SuppressWarnings("serial")
            public class LogOutServlet extends HttpServlet {
                public void doGet(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                    this.doPost(request, response);
                }
            
                public void doPost(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                    // 解决乱码
                    response.setCharacterEncoding("utf-8");
                    response.setContentType("text/html;charst=utf-8");
                    // 杀死session--先进行判断用户是否有session--防止恶意攻击
                    if (request.getSession(false) != null) {
                        request.getSession(false).invalidate();
                    }
                    // 回到主页
                    // 注销中。。。
                    response.getWriter().write("注销成功！正在跳转到主页。。。");
                    response.setHeader("refresh", "2;url=" + request.getContextPath()
                            + "/index.jsp");
                }
            }
     *  RegistServlet
        
        #  #
        
            package com.easymall.web;
            
            import java.io.IOException;
            
            import javax.servlet.ServletContext;
            import javax.servlet.ServletException;
            import javax.servlet.http.HttpServlet;
            import javax.servlet.http.HttpServletRequest;
            import javax.servlet.http.HttpServletResponse;
            
            import com.easymall.domain.User;
            import com.easymall.exception.MsgException;
            import com.easymall.factory.BasicFactory;
            import com.easymall.service.UserService;
            
            @SuppressWarnings("serial")
            public class RegistServlet extends HttpServlet {
                UserService us = BasicFactory.getFactory().getObj(UserService.class);
            
                public void doGet(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                    try {
                        // 0.获取应用参数
                        ServletContext sc = this.getServletContext();
                        String encode = sc.getInitParameter("encode");
            
                        // 1.解决requestpost请求乱码 解决response输出数据乱码
                        request.setCharacterEncoding(encode);
                        response.setCharacterEncoding(encode);
                        response.setContentType("text/html;charset=" + encode);
            
                        // 2.获取请求参数
                        String username = request.getParameter("username");
                        String password = request.getParameter("password");
                        String password2 = request.getParameter("password2");
                        String nickname = request.getParameter("nickname");
                        String email = request.getParameter("email");
                        String valistr = request.getParameter("valistr");
            
                        // 验证码校验--获取请求参数的验证码，获取session中的验证码，对比并进行相应的操作
                        String valistr2 = (String) request.getSession().getAttribute(
                                "valistr2");
                        if (valistr == null || valistr2 == null
                                || !valistr.equals(valistr2)) {
                            request.setAttribute("msg", "验证码不正确！");
                            request.getRequestDispatcher(
                                    request.getContextPath() + "/regist.jsp").forward(
                                    request, response);
                            return;
                        }
                        // 3.检查数据有效性 如果有问题 向浏览器报错
                        if (username == null || "".equals(username)) {
                            throw new MsgException("用户名不能为空！");
                        }
            
                        if (password == null || "".equals(password)) {
                            throw new MsgException("密码不能为空！");
                        }
            
                        if (password2 == null || "".equals(password2)) {
                            throw new MsgException("确认密码不能为空！");
                        }
            
                        if (!password.equals(password2)) {
                            throw new MsgException("两次密码不一致！");
                        }
            
                        if (nickname == null || "".equals(nickname)) {
                            throw new MsgException("昵称不能为空！");
                        }
            
                        if (email == null || "".equals(email)) {
                            throw new MsgException("邮箱不能为空！");
                        }
            
                        if (!email.matches("^\\w+@\\w+(\\.\\w+)+$")) {
                            throw new MsgException("邮箱格式不正确！");
                        }
            
                        if (valistr == null || "".equals(valistr)) {
                            throw new MsgException("验证码不能为空！");
                        }
            
                        // 4.存入数据库
                        User user = new User(-1, username, password, nickname, email);
                        if (us.checkHasUsername(user)) {// 账号重复
                            throw new MsgException("账号重复");
                        } else {// 账号不重复
                            // 存储数据
                            us.addUser(user);
                        }
                        // 5.向浏览器报告成功 回到主页
                        response.getWriter().write("注册成功！正在前往主页------>>>");
                        response.setHeader("refresh", "1;url=" + request.getContextPath()
                                + "/index.jsp");
                    } catch (MsgException e) {
                        String msg = e.getMessage();
                        response.getWriter().write(msg);
                        response.setHeader("refresh", "1;url=/regist.jsp");
                    } catch (Exception e) {
                        e.printStackTrace();
                        throw new RuntimeException(e);
                    }
                }
            
                public void doPost(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                    this.doGet(request, response);
                }
            }
     *  ValiImageServlet.java
        
        #  #
        
            package com.easymall.web;
            
            import java.awt.Color;
            import java.awt.Font;
            import java.awt.Graphics2D;
            import java.awt.image.BufferedImage;
            import java.io.IOException;
            import java.util.Random;
            
            import javax.imageio.ImageIO;
            import javax.servlet.ServletException;
            import javax.servlet.http.HttpServlet;
            import javax.servlet.http.HttpServletRequest;
            import javax.servlet.http.HttpServletResponse;
            
            @SuppressWarnings("serial")
            public class ValiImageServlet extends HttpServlet {
                // 背景参数
                private int base = 30;
                private int height = base;
                private int width = base * 4;
            
                @Override
                protected void doGet(HttpServletRequest req, HttpServletResponse resp)
                        throws ServletException, IOException {
                    // 禁止浏览器缓存图片
                    resp.setHeader("Cache-Control", "no-cache");
                    resp.setHeader("Progma", "no-cache");
                    resp.setDateHeader("Expires", 0);
                    // 创建内存中的图片
                    BufferedImage di = new BufferedImage(width, height,
                            BufferedImage.TYPE_INT_RGB);
                    // 获取画布画背景
                    Graphics2D g2 = (Graphics2D) di.getGraphics();
                    // 填充矩形
                    g2.setColor(Color.white);
                    g2.fillRect(0, 0, width, height);
                    // 绘制边框
                    g2.setColor(Color.red);
                    g2.drawRect(0, 0, width - 1, height - 1);
                    // 写字并保存到session
                    String valistr2 = "";
                    g2.setFont(new Font("微软雅黑", Font.BOLD, 25));
                    for (int i = 0; i < 4; i++) {
                        String s = Integer.toString(getRandom(0, 10));
                        valistr2 += s;
                        g2.setColor(new Color(getRandom(0, 255), getRandom(0, 255),
                                getRandom(0, 255)));
                        int temp = getRandom(-45, 45);
                        g2.rotate(temp / 180.0 * Math.PI, 10 + 30 * i, 20);
                        g2.drawString(s, 10 + 30 * i, 20);
                        g2.rotate(-temp / 180.0 * Math.PI, 10 + 30 * i, 20);
                    }
                    System.out.println("当前验证码：" + valistr2);
                    req.getSession().setAttribute("valistr2", valistr2);
                    // 画干扰线
                    for (int i = 0; i < 3; i++) {
                        g2.setColor(new Color(getRandom(0, 255), getRandom(0, 255),
                                getRandom(0, 255)));
                        g2.drawLine(getRandom(0, width), getRandom(0, height),
                                getRandom(0, width), getRandom(0, height));
                    }
                    // 画干扰点
                    for (int i = 0; i < 5; i++) {
                        g2.setColor(new Color(getRandom(0, 255), getRandom(0, 255),
                                getRandom(0, 255)));
                        g2.drawOval(getRandom(0, width), getRandom(0, height), 5, 5);
                    }
                    // 画出图片
                    ImageIO.write(di, "JPG", resp.getOutputStream());
                    // 关闭画布
                    g2.dispose();
                }
            
                @Override
                protected void doPost(HttpServletRequest req, HttpServletResponse resp)
                        throws ServletException, IOException {
                    this.doGet(req, resp);
                }
            
                // 获取随机数
                private int getRandom(int start, int end) {
                    Random random = new Random();
                    return start + random.nextInt(end - start);
                }
            
            }
 *  配置文件
    
     *  c3p0.properties
        
        #  #
        
            c3p0.driverClass=com.mysql.jdbc.Driver
            c3p0.jdbcUrl=jdbc:mysql://localhost:3306/easymall
            c3p0.user=root
            c3p0.password=root
     *  config.properties
        
        #  #
        
            UserService=com.easymall.service.UserServiceImpl
            UserDao=com.easymall.dao.UserDaoImpl
     *  web.xml
        
        #  #
        
            <?xml version="1.0" encoding="UTF-8"?>
            <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
                http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
            
                
                <context-param>
                    <param-name>encode</param-name>
                    <param-value>utf-8</param-value>
                </context-param>
            
                
                <servlet>
                    <servlet-name>RegistServlet</servlet-name>
                    <servlet-class>com.easymall.web.RegistServlet</servlet-class>
                </servlet>
                <servlet>
                    <servlet-name>CheckHasUsernameServlet</servlet-name>
                    <servlet-class>com.easymall.web.CheckHasUsernameServlet</servlet-class>
                </servlet>
                <servlet>
                    <servlet-name>LoginServlet</servlet-name>
                    <servlet-class>com.easymall.web.LoginServlet</servlet-class>
                </servlet>
                <servlet>
                    <servlet-name>LogOutServlet</servlet-name>
                    <servlet-class>com.easymall.web.LogOutServlet</servlet-class>
                </servlet>
              <servlet>
                <servlet-name>ValiImageServlet</servlet-name>
                <servlet-class>com.easymall.web.ValiImageServlet</servlet-class>
              </servlet>
            
            
                
                <servlet-mapping>
                    <servlet-name>RegistServlet</servlet-name>
                    <url-pattern>/RegistServlet</url-pattern>
                </servlet-mapping>
                <servlet-mapping>
                    <servlet-name>CheckHasUsernameServlet</servlet-name>
                    <url-pattern>/CheckHasUsernameServlet</url-pattern>
                </servlet-mapping>
                <servlet-mapping>
                    <servlet-name>LoginServlet</servlet-name>
                    <url-pattern>/LoginServlet</url-pattern>
                </servlet-mapping>
                <servlet-mapping>
                    <servlet-name>LogOutServlet</servlet-name>
                    <url-pattern>/LogOutServlet</url-pattern>
                </servlet-mapping>
              <servlet-mapping>
                <servlet-name>ValiImageServlet</servlet-name>
                <url-pattern>/ValiImageServlet</url-pattern>
              </servlet-mapping>
            
                
                <welcome-file-list>
                    <welcome-file>index.jsp</welcome-file>
                </welcome-file-list>
            </web-app>
 *  jsp页面（主要看EL+jstl;样式这里省略）
    
     *  foot.jsp
        
        #  #
        
            <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
            <!DOCTYPE HTML>
            <meta http-equiv="Content-type" content="text/html; charset=UTF-8" />
            <link rel="stylesheet" href="css/foot.css" />
            <div id="common_foot">
                <p>
                    Copyright © 2011-2015 达内软件技术有限公司 版权所有 保留一切权利 苏B2-20130048号 |
                    京ICP备09062682号-9 <br> 网络文化经营许可证苏网文[2012]0401-019号
                </p>
            </div>
     *  head.jsp
        
        #  #
        
            <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
            <%@  taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
            <!DOCTYPE HTML>
            <link rel="stylesheet" href="css/head.css" />
            <meta http-equiv="Content-type" content="text/html; charset=UTF-8" />
            
            <div id="common_head">
                <div id="line1">
                    <div id="content">
                        <c:if test="${sessionScope.username!=null}">
                        您好：${sessionScope.username}  |  <a
                                href="${requestScope.contextPath }/LogOutServlet">注销 </a>
                        </c:if>
                        <c:if test="${sessionScope.username==null}">
                            <a href="${requestScope.contextPath }/login.jsp">登录</a>  |  <a
                                href="${requestScope.contextPath }/regist.jsp">注册</a>
                        </c:if>
                    </div>
                </div>
                <div id="line2">
                    <img id="logo" src="img/head/logo.jpg" /> <input type="text" name="" />
                    <input type="button" value="搜索" /> <span id="goto"> <a
                        id="goto_order" href="#">我的订单</a> <a id="goto_cart" href="#">我的购物车</a>
                    </span> <img id="erwm" src="img/head/qr.jpg" />
                </div>
                <div id="line3">
                    <div id="content">
                        <ul>
                            <li><a href="#">首页</a>
                            </li>
                            <li><a href="#">全部商品</a>
                            </li>
                            <li><a href="#">手机数码</a>
                            </li>
                            <li><a href="#">电脑平板</a>
                            </li>
                            <li><a href="#">家用电器</a>
                            </li>
                            <li><a href="#">汽车用品</a>
                            </li>
                            <li><a href="#">食品饮料</a>
                            </li>
                            <li><a href="#">图书杂志</a>
                            </li>
                            <li><a href="#">服装服饰</a>
                            </li>
                            <li><a href="#">理财产品</a>
                            </li>
                        </ul>
                    </div>
                </div>
            </div>
     *  index.jsp
        
        #  #
        
            <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"
                buffer="0kb"%>
            <!DOCTYPE HTML>
            <html>
            <head>
            <meta http-equiv="Content-type" content="text/html; charset=UTF-8" />
            <link rel="stylesheet" href="css/index.css" />
            <title>欢迎光临EasyMall</title>
            </head>
            <body>
                <%@include file="head.jsp"%>
                <div id="index">
                    <div id="line1">
                        <img src="img/index/banner_big.jpg" />
                    </div>
                    <div id="line2">
                        <img id="line2_1" src="img/index/adv1.jpg" /> <img id="line2_2"
                            src="img/index/adv2.jpg" /> <img id="line2_3"
                            src="img/index/adv_l1.jpg" />
                    </div>
                    <div id="line3">
                        <img id="line3_1" src="img/index/adv3.jpg" /> <img id="line3_2"
                            src="img/index/adv4.jpg" />
                        <div id="line3_right">
                            <img id="line3_3" src="img/index/adv_l2.jpg" /> <img id="line3_4"
                                src="img/index/adv_l3.jpg" />
                        </div>
                    </div>
                    <div id="line4">
                        <img src="img/index/217.jpg" />
                    </div>
                    <div id="line5">
                        <span id="line5_1"> <img src="img/index/icon_g1.png" />  500强企业
                            品质保证 </span> <span id="line5_2"> <img src="img/index/icon_g2.png" />  7天退货
                            15天换货 </span> <span id="line5_3"> <img src="img/index/icon_g3.png" />  100元起免运费
                        </span> <span id="line5_4"> <img src="img/index/icon_g4.png" />  448家维修网点
                            全国联保 </span>
                    </div>
                </div>
                <%@include file="foot.jsp"%>
            </body>
            </html>
     *  login.jsp
        
        #  #
        
            <%@page import="java.net.URLDecoder"%>
            <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
            <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
            <!DOCTYPE HTML>
            <html>
            <head>
            <meta http-equiv="Content-type" content="text/html; charset=UTF-8" />
            <link rel="stylesheet" href="css/login.css" />
            <title>EasyMall欢迎您登陆</title>
            </head>
            <body>
                <h1>欢迎登陆EasyMall</h1>
                <form action="/LoginServlet" method="POST">
                    <table>
                        <c:if test="${param.msg!=null}">
                            <tr>
                                <td colspan='2'><font color='#ff0000'> <%=new String(request.getParameter("msg").getBytes(
                                    "iso8859-1"), "utf-8")%> </font>
                                </td>
                            </tr>
                        </c:if>
                        <tr>
                            <td class="tdx">用户名:</td>
                            <td><input type="text" name="username" id="username" value="${cookie.remname.value}" />
                            </td>
                        </tr>
                        <tr>
                            <td class="tdx">密码:</td>
                            <td><input type="password" name="password" /></td>
                        </tr>
                        <tr>
                            <td colspan="2"><input type="checkbox" name="remname"
                                value="true"
                                <c:if test="${cookie.remname!=null }">checked="checked"</c:if> />记住用户名
                                <input type="checkbox" name="autologin" value="true" />30天内自动登陆</td>
                        </tr>
                        <tr>
                            <td colspan="2"><input type="submit" value="登陆" />
                            </td>
                        </tr>
                    </table>
                </form>
                <script type="text/javascript">
                    //给账号设值
                    var username = "${cookie.remname.value}";
                    document.getElementById("username").value = decodeURIComponent(username);
                </script>
            </body>
            </html>
     *  regist.jsp
        
        #  #
        
            <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
            <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
            <!DOCTYPE HTML>
            <html>
            <head>
            <title>欢迎注册EasyMall</title>
            <meta http-equiv="Content-type" content="text/html; charset=UTF-8" />
            <link rel="stylesheet" href="css/regist.css" />
            <script type="text/javascript" src="js/jquery-1.4.2.js"></script>
            <script type="text/javascript">
                $(document).ready(
                        function() {
                            var canSubmit = true;//提交的标志
                            //用户名已存在检查（ajax）    
                            $("input[name='username']").blur(
                                    function() {
                                        if ($("input[name='username']").val() != "") {
                                            $.get("/CheckHasUsernameServlet?"
                                                    + $.param({
                                                        "username" : $(
                                                                "input[name='username']")
                                                                .val()
                                                    }), function(data) {
                                                if ($.parseJSON(data).hasUser) {
                                                    //提示该账户已有
                                                    $("input[name='username']")
                                                            .next("span").text("用户名重复!");
                                                    canSubmit = false;
                                                } else {
                                                    $("input[name='username']")
                                                            .next("span").text("");
                                                    canSubmit = true;
                                                }
                                            });
                                        }
                                    });
            
                            //两次密码的一致性检验(失去焦点)
                            $("input[name='password2']").blur(
                                    function() {
                                        if ($("input[name='password2']").val() != "") {
                                            if ($("input[name='password']").val() != $(
                                                    "input[name='password2']").val()) {//密码不一致
                                                $("input[name='password2']").next("span")
                                                        .text("密码不一致!");
                                                canSubmit = false;
                                            } else {
                                                $("input[name='password2']").next("span")
                                                        .text("");
                                                canSubmit = true;
                                            }
                                        }
                                    });
                            //检查邮箱的格式是否正确
                            $("input[name='email']").blur(function() {
                                var email_Reg = /^\w+@\w+(\.\w+)+$/;
                                if ($(this).val() != "" && email_Reg.test($(this).val())) {
                                    $(this).next("span").text("");
            
                                    canSubmit = true;
                                } else {
                                    $(this).next("span").text("邮箱格式不正确！");
                                    canSubmit = false;
                                }
                            });
                            //验证码切换（点击事件）
                            $("#yzm_img").click(
                                    function() {
                                        $(this).attr(
                                                "src",
                                                "/ValiImageServlet?time="
                                                        + new Date().getTime());
                                    });
                            //表单提交事件
                            $("form").submit(function() {
                                //判断所有的输入框是否为空
                                $.each($("input[type!='submit']"), function() {
                                    if ($(this).val() == "") {//密码不一致
                                        $(this).nextAll("span").text("数据不能为空！");
                                        canSubmit = false;
                                    } else {
                                        $(this).nextAll("span").text("");
                                        canSubmit = true;
                                    }
                                });
                                return canSubmit;
                            });
                        });
            </script>
            </head>
            <body>
                <h1>欢迎注册EasyMall</h1>
                <form action="/RegistServlet" method="POST" onsubmit="">
                    <table>
                        <tr>
                            <td class="tds">用户名：</td>
                            <td><input type="text" name="username"
                                value="${param.username }"><span></span></td>
                        </tr>
                        <tr>
                            <td class="tds">密码：</td>
                            <td><input type="password" name="password"><span></span>
                            </td>
                        </tr>
                        <tr>
                            <td class="tds">确认密码：</td>
                            <td><input type="password" name="password2"><span></span>
                            </td>
                        </tr>
                        <tr>
                            <td class="tds">昵称：</td>
                            <td><input type="text" name="nickname"
                                value="${param.nickname }"><span></span></td>
                        </tr>
                        <tr>
                            <td class="tds">邮箱：</td>
                            <td><input type="text" name="email" value="${param.email }"><span></span>
                            </td>
                        </tr>
                        <tr>
                            <td class="tds">验证码：</td>
                            <td><input type="text" name="valistr"><img id="yzm_img"
                                src="/ValiImageServlet" style="cursor: pointer" /><span><font
                                    color="#ff0000">${requestScope.msg }</font> </span>
                            </td>
                        </tr>
                        <tr>
                            <td colspan="2"><input type="submit" value="注册用户" /></td>
                        </tr>
                    </table>
                </form>
            </body>
            </html>
 *  所需jar包
    
     *  ![7w1tOyf.png][]

[GPWVdPB.png]: https://i.imgur.com/GPWVdPB.png
[lDFrjsm.png]: https://i.imgur.com/lDFrjsm.png
[cvfp7G3.png]: https://i.imgur.com/cvfp7G3.png
[R1E90UH.png]: https://i.imgur.com/R1E90UH.png
[dV6Ce5A.png]: https://i.imgur.com/dV6Ce5A.png
[66lix6m.png]: https://i.imgur.com/66lix6m.png
[ktfBzbA.png]: https://i.imgur.com/ktfBzbA.png
[qntiQX2.png]: https://i.imgur.com/qntiQX2.png
[7w1tOyf.png]: https://i.imgur.com/7w1tOyf.png