Tomcat+Servlet+JDBC+DAO三层架构+动态代理设计模式+注解log实现注册登录

0. 需求图和流程图

功能需求图：

整体框架图：

键来！~

1. 实体类 Entity

package com.demo.entity;
public class Userinfo {
    private String username;
    private String password;

    public Userinfo() {
    }

    public Userinfo(String username, String password) {
        this.username = username;
        this.password = password;
    }

    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;
    }

    @Override
    public String toString() {
        return "Userinfo{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

2. 封装数据层 Dao

2.0 数据库连接池：配置文件 + 连接工具类

# 数据库配置
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/companydb?useUnicode=true&characterEncoding=utf-8
username=root
password=123456
# 初始化连接数
initialSize=10
# 最大连接数
maxActive=50
# 最小空闲连接数
minIdle=5
# 超时等待时间,单位：毫秒ms
maxWait=5000

package com.demo.utils;
public class DBUtils {
    private static DruidDataSource druidDataSource = null;
    private static final ThreadLocal<Connection> THREAD_LOCAL = new ThreadLocal<>();

    static {
        Properties ppts = new Properties();
        InputStream is = DBUtils.class.getClassLoader().getResourceAsStream("database.properties");
        try {
            ppts.load(is);
            druidDataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(ppts);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static DruidDataSource getDruidDataSource() {
        return druidDataSource;
    }

    private static Connection getConnection() {
        Connection connection = THREAD_LOCAL.get();
        try {
            if (null == connection) {
                connection = getDruidDataSource().getConnection();
                THREAD_LOCAL.set(connection);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }

    public static void begin() {
        try {
            getConnection().setAutoCommit(false);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void commit() {
        try {
            getConnection().commit();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void rollback() {
        try {
            getConnection().rollback();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void release(Connection connection, Statement statement, ResultSet resultSet) {
        try {
            if (null != resultSet) {
                resultSet.close();
            }
            if (null != statement) {
                statement.close();
            }
            if (null != connection) {
                connection.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

2.1 接口 UserinfoDao

package com.demo.dao;
public interface UserinfoDao {
    int insert(Userinfo userinfo);

    Userinfo delete(int id);

    int update(Userinfo userinfo);

    Userinfo search(int id);

    Userinfo search(String username);
}

2.2 实现类 UserifoDaoImpl

package com.demo.dao.impl;
public class UserinfoDaoImpl implements UserinfoDao {
    private QueryRunner queryRunner = new QueryRunner(DBUtils.getDruidDataSource());
    @Override
    public int insert(Userinfo userinfo) {
        String sql = "insert into userinfo(username, password) value(?,?)";
        Object[] params = {userinfo.getUsername(), userinfo.getPassword()};
        try {
            return queryRunner.update(sql, params);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return 0;
    }

    @Override
    public Userinfo delete(int id) {
        String sql = "delete from userinfo where id=?";
        try {
            return queryRunner.update(sql, id) > 0 ? search(id) : null;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public int update(Userinfo userinfo) {
        String sql = "update userinfo set username=?,password=? where id=?";
        Object[] params = {userinfo.getUsername(), userinfo.getPassword()};
        try {
            return queryRunner.update(sql, params);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return 0;
    }

    @Override
    public Userinfo search(int id) {
        return doSearch("id", id);
    }

    @Override
    public Userinfo search(String username) {
        return doSearch("username", username);
    }

    private Userinfo doSearch(String param, Object value) {
        String sql = "select * from userinfo where " + param + "=?";
        try {
            return queryRunner.query(sql, new BeanHandler<>(Userinfo.class), value);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}

3. 业务逻辑层 Service

3.0 日志管理：注解 + 动态代理 + 日期工具类

package com.demo.anno;
@Retention(RetentionPolicy.RUNTIME)
public @interface SysLog {
}

package com.demo.utils;
public class DateUtils {
    private static final SimpleDateFormat SIMPLE_DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

    public static String utilToStrDate(java.util.Date date) {
        return SIMPLE_DATE_FORMAT.format(date);
    }

    public static java.util.Date strToUtilDate(String date) {
        try {
            return SIMPLE_DATE_FORMAT.parse(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static java.sql.Date utilToSqlDate(java.util.Date date) {
        return new java.sql.Date(date.getTime());
    }
}

package com.demo.service.proxy;
public class UserinfoServiceProxy {
    private UserinfoService userinfoService;

    public UserinfoServiceProxy(UserinfoService userinfoService) {
        this.userinfoService = userinfoService;
    }

    public UserinfoService getDynamicProxyInstance() {
        return (UserinfoService) Proxy.newProxyInstance(
                userinfoService.getClass().getClassLoader(),
                userinfoService.getClass().getInterfaces(),
                (proxy, method, args) -> {
                    Object result;
                    boolean present = method.isAnnotationPresent(SysLog.class);
                    if (present) {
                        String strDate = DateUtils.utilToStrDate(new Date());
                        String className = userinfoService.getClass().getName();
                        String methodName = method.getName();
                        System.out.print("[" + strDate + "]|" + className + "|" + methodName + "(");
                        for (Object param : args) {
                            System.out.print(param + ",");
                        }
                        System.out.println(")");
                        result = method.invoke(userinfoService, args);
                        System.out.println("[" + strDate + "]|" + className + "|" + methodName + "() return:" + result);
                    } else {
                        result = method.invoke(userinfoService, args);
                    }
                    return result;
                });
    }
}

3.1 接口 UserinfoService

package com.demo.service;
public interface UserinfoService {
    @SysLog
    int add(String username, String password);
    @SysLog
    Userinfo del(int id);
    @SysLog
    int change(Userinfo userinfo);
    @SysLog
    Userinfo get(int id);
    @SysLog
    boolean login(String username, String password);
}

3.2 实现类 UserinfoServiceImpl

package com.demo.service.impl;
public class UserinfoServiceImpl implements UserinfoService {
    private UserinfoDao userinfoDao = new UserinfoDaoImpl();

    @Override
    public int add(String username, String password) {
        DBUtils.begin();
        if (userinfoDao.search(username) != null) {
            System.out.println("用户名重复，请重试！");
            return -1;
        }
        int result = userinfoDao.insert(new Userinfo(username, password));
        if (result > 0) {
            DBUtils.commit();
        } else {
            DBUtils.rollback();
        }
        return result;
    }

    @Override
    public Userinfo del(int id) {
        DBUtils.begin();
        Userinfo userinfo = userinfoDao.delete(id);
        if (null != userinfo) {
            DBUtils.commit();
        } else {
            DBUtils.rollback();
        }
        return userinfo;
    }

    @Override
    public int change(Userinfo userinfo) {
        DBUtils.begin();
        int result = userinfoDao.update(userinfo);
        if (result > 0) {
            DBUtils.commit();
        } else {
            DBUtils.rollback();
        }
        return result;
    }

    @Override
    public Userinfo get(int id) {
        DBUtils.begin();
        Userinfo userinfo = userinfoDao.search(id);
        if (null != userinfo) {
            DBUtils.commit();
        } else {
            DBUtils.rollback();
        }
        return userinfo;
    }

    @Override
    public boolean login(String username, String password) {
        DBUtils.begin();
        Userinfo userSearch = userinfoDao.search(username);
        if (null != userSearch) {
            return password.equals(userSearch.getPassword());
        }
        return false;
    }
}

4. 请求和响应处理 Servlet

4.1 注册 register

package com.demo.servlet;
@WebServlet(name = "RegisterServlet", urlPatterns = "/register")
public class RegisterServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");

        String username = request.getParameter("username");
        String password = request.getParameter("password");
        if (username == null || password == null ||
                username.trim().length() == 0 || password.trim().length() == 0) {
            regFailed("账号/密码不能为空", response);
            return;
        }

        UserinfoServiceProxy userinfoServiceProxy = new UserinfoServiceProxy(new UserinfoServiceImpl());
        UserinfoService proxyInstance = userinfoServiceProxy.getDynamicProxyInstance();
        int addResult = proxyInstance.add(username, password);
        if (addResult > 0) {
            response.sendRedirect("/demo55/login/login.html");
        } else {
            regFailed("账号已存在", response);
        }
    }

    private void regFailed(String errInfo, HttpServletResponse response) throws IOException {
        response.getWriter().println(errInfo + "，注册失败！");
        response.setHeader("refresh", "3;url=/demo55/register/register.html");
    }
}

4.2 登录 login

package com.demo.servlet;
@WebServlet(name = "LoginServlet", urlPatterns = "/login")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");

        String username = request.getParameter("username");
        String password = request.getParameter("password");
        if (username == null || password == null ||
                username.trim().length() == 0 || password.trim().length() == 0) {
            loginFailed("账号/密码不能为空", response);
            return;
        }

        UserinfoServiceProxy userinfoServiceProxy = new UserinfoServiceProxy(new UserinfoServiceImpl());
        UserinfoService proxyInstance = userinfoServiceProxy.getDynamicProxyInstance();
        if (proxyInstance.login(username, password)) {
            request.setAttribute("userName", username);
            request.getRequestDispatcher("/user").forward(request, response);
        } else {
            loginFailed("账号/密码有误", response);
        }
    }

    private void loginFailed(String errInfo, HttpServletResponse response) throws IOException {
        response.getWriter().println(errInfo + "，登陆失败！");
        response.setHeader("refresh", "3;url=/demo55/login/login.html");
    }
}

4.3 用户中心 user

package com.demo.servlet;
@WebServlet(name = "UserServlet", urlPatterns = "/user")
public class UserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");

        String uName = (String) request.getAttribute("userName");
        if (null != uName) {
            PrintWriter writer = response.getWriter();
            writer.println("<html>");
            writer.println("<head>");
            writer.println("<meat charset='utf-8'>");
            writer.println("</head>");
            writer.println("<body>");
            writer.println("<font color=\"red\">" + uName + "</font>,欢迎回来！");
            writer.println("</body>");
            writer.println("</html>");
        }
    }
}

5. 表示层页面 WebPage

5.1 index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>注册和登陆</title>
</head>
<body>
<h2>请选择需要的功能：</h2>
<a href="register/register.html"><input type="button" value="注册" /></a>
<a href="login/login.html"><input type="button" value="登陆" /></a>
</body>
</html>

5.2 register.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>注册页面</title>
</head>
<body>
<h2>注册：</h2>
<form action="/demo55/register" method="post">
    <table>
        <tr>
            <td>账号：</td>
            <td>
                <label>
                    <input type="text" name="username" placeholder="请输入用户名"/>
                </label>
            </td>
        </tr>
        <tr>
            <td>密码：</td>
            <td>
                <label>
                    <input type="password" name="password" placeholder="请输入密码"/>
                </label>
            </td>
        </tr>
    </table>
    <input type="submit" value="注册"/>
    <input type="reset" value="重置"/>
</form>
</body>
</html>

5.3 login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>登陆页面</title>
</head>
<body>
<h2>登陆：</h2>
<form action="/demo55/login" method="post">
    <table>
        <tr>
            <td>账号：</td>
            <td>
                <label>
                    <input type="text" name="username" placeholder="请输入用户名"/>
                </label>
            </td>
        </tr>
        <tr>
            <td>密码：</td>
            <td>
                <label>
                    <input type="password" name="password" placeholder="请输入密码"/>
                </label>
            </td>
        </tr>
    </table>
    <input type="submit" value="登陆"/>
</form>
</body>
</html>

6. 运行结果示例图

6.1 日志记录

6.2 页面操作

6.3 数据库数据