javaweb超市管理系统demo

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SMBMS

数据库:

项目搭建准备工作

搭建一个maven web项目
配置tomcat
测试项目是否能够跑起来

导入项目中可能会遇到的Jar包
jsp,Servlet,mysql驱动,jstl,stander......

  <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.3.3</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
  <dependency>
            <groupId>javax.servlet.jsp.jstl</groupId>
            <artifactId>jstl-api</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>

创建项目包结构
编写实体类
ORM映射: 表-类映射

ORM映射: 表-类映射

编写基础公共类

数据库配置文件
db.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=utf8&useSSL=true
username=root
password=123456

编写数据库的公共类(工具类)

package com.tan.dao;

import java.sql.ResultSet;
import java.sql.*;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.util.Properties;

/**
 * @author null
 * @date 2020/5/19
 */

//操作数据类的公共类
public class BaseDao {
    private static String driver;
    private static String url;
    private static String username;
    private static String password;

    //静态代码块,类加载的时候就初始化了
    static {
        Properties properties = new Properties();
        //通过类加载器读取相应的资源
        InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");

        try {
            properties.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        }

        driver = properties.getProperty("driver");
        url = properties.getProperty("url");
        username = properties.getProperty("username");
        password = properties.getProperty("password");
    }

    //获取数据库的链接
    public static Connection getConnection() {
        Connection connection = null;
        try {
            Class.forName(driver);
            connection = DriverManager.getConnection(url, username, password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return connection;
    }

    //编写查询公共方法
    public static ResultSet execute(Connection connection,PreparedStatement preparedStatement, ResultSet resultSet,String sql, Object[] params) throws SQLException {
        //预编译的sql,在后面直接执行就可以了
        preparedStatement = connection.prepareStatement(sql);

        for (int i = 0; i < params.length; i++) {
            //setObject,占位符从1开始,但是我们的数据是从0开始!
            preparedStatement.setObject(i + 1, params[i]);

        }
        preparedStatement.executeQuery();
        return resultSet;
    }

    //编写增删改的公共方法
    public static int execute(Connection connection,PreparedStatement preparedStatement, String sql, Object[] params) throws SQLException {
        preparedStatement = connection.prepareStatement(sql);

        for (int i = 0; i < params.length; i++) {
            //setObject,占位符从1开始,但是我们的数据是从0开始!
            preparedStatement.setObject(i + 1, params[i]);

        }
        int updateRows = preparedStatement.executeUpdate();
        return updateRows;
    }

    //释放资源
    public static boolean closeResource(ResultSet resultSet, PreparedStatement preparedStatement, Connection connection) {
        boolean flag = true;

        if (resultSet != null) {
            try {
                resultSet.close();
                //GC回收
                resultSet = null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag = false; //相当于没有释放成功
            }
        }

        if (preparedStatement != null) {
            try {
                preparedStatement.close();
                //GC回收
                preparedStatement = null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag = false; //相当于没有释放成功
            }
        }

        if (connection != null) {
            try {
                connection.close();
                //GC回收
                connection = null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag = false; //相当于没有释放成功
            }
        }
        return flag;
    }
}

编写字符编码过滤器

public class CharacterEncodingFilter implements Filter {
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html; charset=UTF-8");

        chain.doFilter(request, response);
    }

    public void destroy() {

    }
}

配置字符编码过滤器的web.xml

    <!--字符编码过滤器-->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>com.tan.filter.CharacterEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

导入静态资源

登录功能实现

编写前端页面

设置首页

   <!--设置欢迎页面-->
    <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>

编写dao层用户登录的登录接口

public interface UserDao  {

    /*得到要登录的用户*/
    public User getLoginUser(Connection connection, String userCode) throws SQLException;
}

编写dao接口的实现类

public class UserDaoImpl implements UserDao {

    PreparedStatement pstm = null;
    ResultSet rs = null;
    User user = null;

    public User getLoginUser(Connection connection, String userCode) throws SQLException {

        if (connection != null) {
            String sql = "select from smbms_user where userCode=?";
            Object[] params = {userCode};

                rs = BaseDao.execute(connection, pstm, rs, sql, params);

                if (rs.next()) {
                    user = new User();
                    user.setId(rs.getInt("id"));
                    user.setUserCode(rs.getString(userCode));
                    user.setUserName(rs.getString("userPassword"));
                    user.setGender(rs.getInt("gender"));
                    user.setBirthday(rs.getDate("birthday"));
                    user.setPhone(rs.getString("phone"));
                    user.setAddress(rs.getString("address"));
                    user.setUserRole(rs.getInt("userRole"));
                    user.setCreatedBy(rs.getInt("createdBy"));
                    user.setCreationDate(rs.getTimestamp("creationDate"));
                    user.setModifyBy(rs.getInt("modifyBy"));
                    user.setModifyDate(rs.getTimestamp("modifyDate"));
                }

                BaseDao.closeResource(connection, pstm,rs);

        }

        return user;
    }
}

业务层接口

public interface UserService {
    //用户登录
    public User login(String userCode, String password);
}

业务层接口实现类

public class UserServiceImpl implements UserService {

    //业务层都会调dao层,所以我们要引入Dao层
    private UserDao userDao;

    public UserServiceImpl() {
        userDao = new UserDaoImpl();
    }

    public User login(String userCode, String password) {
        Connection connection = null;
        User user = null;

        try {
            connection = BaseDao.getConnection();
            //通过业务层调用对应的具体的数据库操作
            user = userDao.getLoginUser(connection, userCode);

        } catch (SQLException throwables) {
            throwables.printStackTrace();
        } finally {
            BaseDao.closeResource(connection, null, null);
        }
        return user;
    }

}

编写Servlet

public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("LoginServlet----start.....");

        //获取用户的账号密码
        String userCode = req.getParameter("userCode");
        String userPassword = req.getParameter("userPassword");

        //和数据库的密码进行对比,调用业务层
        UserService userService = new UserServiceImpl();
        User user = userService.login(userCode, userPassword);
        if (user != null && userPassword.equals(user.getUserPassword())) {//查到有人可以登录,与数据库的密码进行对比
            //将用户的信息放到Session中
            req.getSession().setAttribute(Constants.USER_SESSION,user);
            //跳到内部主页
            resp.sendRedirect("jsp/frame.jsp");
        }else {//查无此人,无法登录
            //转发回登陆页面,顺带提示用户名或密码错误
            req.setAttribute("error","用户名或者密码不正确");
            req.getRequestDispatcher("login.jsp").forward(req, resp);
        }

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

注册Servlet

<!--Servlet-->
<servlet>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>com.tan.servlet.user.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/login.do</url-pattern>
</servlet-mapping>

测试访问,确保以上功能成功!

登录功能优化

注销功能:

思路: 移除session,返回登陆界面

public class LogoutServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //移除用户的Constants.USER_SESSION
        req.getSession().removeAttribute(Constants.USER_SESSION);
        resp.sendRedirect("/login.jsp");//返回登陆页面
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

注册xml

    <servlet>
        <servlet-name>LogoutServlet</servlet-name>
        <servlet-class>com.tan.servlet.user.LogoutServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LogoutServlet</servlet-name>
        <url-pattern>/jsp/logout.do</url-pattern>
    </servlet-mapping>

登录拦截优化

退出后仍可以直接进入,过滤器优化

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

    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) resp;

        //从Session中获取用户
        User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);

        if (user == null) {//已被移除注销,或者登录
            response.sendRedirect("/smbms/error.jsp");
        }else {
            chain.doFilter(req, resp);
        }
    }

    @Override
    public void destroy() {

    }
}

配置xml

    <!--登录优化过滤器-->
    <filter>
        <filter-name>SysFilter</filter-name>
        <filter-class>com.tan.filter.SysFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>SysFilter</filter-name>
        <url-pattern>/jsp/*</url-pattern>
    </filter-mapping>

测试,登录,注销,权限,都要保证OK!

密码修改

导入前端素材

<li><a href="${pageContext.request.contextPath }/jsp/pwdmodify.jsp">密码修改</a></li>

写项目,建议从底层向上写

UserDao 接口

//修改当前用户密码
public int updatePwd(Connection connection, int id, String password) throws SQLException;

UserDao 接口实现类

    @Override
    //修改当前用户密码
    public int updatePwd(Connection connection, int id, String password) throws SQLException {
        PreparedStatement pstm = null;
        int execute = 0;

        if(connection!=null){
            Object params[] = {password, id};
            String sql = "update smbms_user set userPassword = ? where id = ?";
            execute = BaseDao.execute(null, pstm, sql, params);
            BaseDao.closeResource(null, pstm, null);
        }

        return execute;
    }
}

UserService层

//根据用户ID修改密码
public boolean updatePwd(int id, String pwd);

UserService层实现类

    @Override
    public boolean updatePwd(int id, String pwd) {
        Connection connection = null;
        boolean flag = false;

        connection = BaseDao.getConnection();
        //修改密码
        try {
            if (userDao.updatePwd(connection, id, pwd)>0) {
                flag = true;
            }
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            BaseDao.closeResource(connection, null, null);
        }
        return flag;
    }

记得实现复用,需要提取出方法

String method = req.getParameter("method");
if (method.equals("savepwd") && method != null) {
    this.updatePwd(req,resp);
}

提取出的方法:

    //写成方法实现Servlet的复用
    public void updatePwd (HttpServletRequest req, HttpServletResponse resp){
        //从Session里面拿ID
        Object o = req.getSession().getAttribute(Constants.USER_SESSION);
        String newpassword = req.getParameter("newpassword");

        boolean flag = false;

        if (o != null && newpassword != null && newpassword.length() != 0) {
            UserServiceImpl userService = new UserServiceImpl();
            flag = userService.updatePwd(((User) o).getId(), newpassword);
            if (flag) {
                req.setAttribute("message", "修改密码成功,请退出重新登陆.");
                //密码修改成功,移除当前Session
                req.getSession().removeAttribute(Constants.USER_SESSION);
            } else {
                req.setAttribute("message", "密码修改失败");
            }
        } else {
            req.setAttribute("message", "新密码有问题");
        }
        try {
            req.getRequestDispatcher("pwdmodify.jsp").forward(req, resp);
        } catch (ServletException | IOException e) {
            e.printStackTrace();
        }
    }
}

记配置web.xml

测试

优化密码修改使用Ajax

阿里巴巴fastjson

  <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>

后台代码修改

//验证旧密码
public void pwdModify(HttpServletRequest req, HttpServletResponse resp) {
    //从Session里面拿ID
    Object o = req.getSession().getAttribute(Constants.USER_SESSION);
    String oldpassword = req.getParameter("oldpassword");//获取从pwdmodify.js里Ajax的参数,连接前端

    //万能的Map : 结果集
    HashMap<String, String> resultMap = new HashMap<>();

    if (o == null) {//Session过期或者失效了
        resultMap.put("result", "sessionerror");
    } else if (StringUtils.isNullOrEmpty(oldpassword)) {//输入的密码为空
        resultMap.put("result", "false");
    } else {
        String userPassword = ((User) o).getUserPassword();//Session中获取用户的老密码
        if (oldpassword.equals(userPassword)) {
            resultMap.put("result", "true");//输入密码正确
        } else {
            resultMap.put("result", "true");//输入密码输入不正确
        }
    }

    try {
        resp.setContentType("application/json");//限定为json格式
        PrintWriter writer = resp.getWriter();//给个流
        //使用阿里巴巴JSON工具类
        /*
        将Map格式转化为JSON格式
        */
        writer.write(JSONArray.toJSONString(resultMap));
        writer.flush();
        writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

调试

用户管理实现(实在是太多,放弃做笔记了)

思路:

导入分页的工具类
用户列表页面导入

1.获取用户数量

UserDao
UserDaoImpl
UserService
UserServiceImpl

posted @ 2020-06-02 10:07 Vlats 阅读(2831) 评论(7) 编辑收藏举报

刷新页面返回顶部

Vlats