超市订单管理系统源码

1.项目搭建准备工作

1. 搭建一个maven web项目

2. 配置Tomcat

3. 测试项目环境是否能跑起来

4. 导入jar包（jsp、servlet、mysql驱动、jstl、standard…）

5. 创建项目包结构

6. 编写实体类（ORM映射）

7. 编写基础公共类

   1. 数据库配置文件

      driver=com.mysql.jdbc.Driver
      url=jdbc:mysql://localhost:3306/smbms?useUnicode=true&characterEncoding=utf-8&useSSL=true
      username=root
      password=123456
      

   2. 编写数据库的公共类

      //操作数据库的公共类
      public class BaseDao {
          private static String driver;
          private static String url;
          private static String username;
          private static String password;
      
          //静态代码块，类加载的时候就会初始化
          static{
              Properties properties = new Properties();
              //通过类加载器读取对应的资源
              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");
          }
      
          //获取数据库的连接
          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 {
              preparedStatement = connection.prepareStatement(sql);
      
              for (int i = 0; i < params.length; i++) {
                  //setObject占位符从1开始，但是数据从0开始
                  preparedStatement.setObject(i+1,params[i]);
              }
      
              resultSet = preparedStatement.executeQuery();
              return resultSet;
          }
      
          //编写增、删、改公共方法
          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，但是数据从0开始
                  preparedStatement.setObject(i+1,params[i]);
              }
      
              int updateRows = preparedStatement.executeUpdate();
              return updateRows;
          }
      
          //释放资源
          public static boolean closeResource(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet){
              boolean flag = true;
      
              if (resultSet != null){
                  try {
                      resultSet.close();
                      //gc回收
                      resultSet = null;
                  } catch (SQLException e) {
                      e.printStackTrace();
                      flag = false;
                  }
              }
              if (preparedStatement != null){
                  try {
                      preparedStatement.close();
                      //gc回收
                      preparedStatement = null;
                  } catch (SQLException e) {
                      e.printStackTrace();
                      flag = false;
                  }
              }
              if (connection != null){
                  try {
                      connection.close();
                      //gc回收
                      connection = null;
                  } catch (SQLException e) {
                      e.printStackTrace();
                      flag = false;
                  }
              }
              return flag;
          }
      }
      

   3. 编写字符编码过滤器

      public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
          servletRequest.setCharacterEncoding("utf-8");
          servletResponse.setCharacterEncoding("utf-8");
          filterChain.doFilter(servletRequest,servletResponse);
      }
      

8. 导入静态资源（css，js，image…）

2.登录功能实现

• 流程分析：

1. 编写前端页面

2. 设置主页

   <!--设置首页-->
   <welcome-file-list>
       <welcome-file>login.jsp</welcome-file>
   </welcome-file-list>
   

3. 编写dao层用户登录接口（UserDao）

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

4. 编写dao接口的实现类（UserDaoImpl）

   //得到要登录的用户
   public User getLoginUser(Connection connection, String userCode, String userPassword) throws SQLException {
   
       PreparedStatement preparedStatement = null;
       ResultSet resultSet = null;
       User user = null;
   
       if (connection != null){
           String sql = "select * from smbms_user where userCode=? and userPassword=?";
           Object[] params = {userCode,userPassword};
   
           resultSet = BaseDao.execute(connection, preparedStatement, resultSet, sql, params);
           if (resultSet.next()){
               user = new User();
               user.setId(resultSet.getInt("id"));
               user.setUserCode(resultSet.getString("userCode"));
               user.setUserName(resultSet.getString("userName"));
               user.setUserPassword(resultSet.getString("userPassword"));
               user.setGender(resultSet.getInt("gender"));
               user.setBirthday(resultSet.getDate("birthday"));
               user.setPhone(resultSet.getString("phone"));
               user.setAddress(resultSet.getString("address"));
               user.setUserRole(resultSet.getInt("userRole"));
               user.setCreatedBy(resultSet.getInt("createdBy"));
               user.setCreationDate(resultSet.getDate("creationDate"));
               user.setModifyBy(resultSet.getInt("modifyBy"));
               user.setModifyDate(resultSet.getDate("modifyDate"));
           }
           BaseDao.closeResource(null,preparedStatement,resultSet);
       }
       return user;
   }
   

5. 业务层接口（UserService）

   //用户登录
   public User login(String userCode,String userPassword);
   

6. 业务层实现类（UserServiceImpl）

   //业务层都会调用dao层
   private UserDao userDao;
   public UserServiceImpl(){
       userDao = new UserDaoImpl();
   }
   
   public User login(String userCode, String userPassword) {
       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层
           user = userDao.getLoginUser(connection,userCode,userPassword);
       } catch (SQLException e) {
           e.printStackTrace();
       }finally {
           BaseDao.closeResource(connection,null,null);
       }
       return user;
   }
   

7. 编写Servlet

   //控制层调用业务层
   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       //获取用户名和密码
       String userCode = req.getParameter("userCode");
       String userPassword = req.getParameter("userPassword");
   
       //和数据库中的密码进行对比，调用业务层
       UserServiceImpl userService = new UserServiceImpl();
       User user = userService.login(userCode, userPassword);
   
       if (user != null){
           //登录成功将用户信息写入到Session
           req.getSession().setAttribute(Constants.USER_SESSION,user);
           //跳转主页
           resp.sendRedirect("jsp/frame.jsp");
       }else {
           //无法登录，转发回登录页面，提示用户名或密码错误
           req.setAttribute("error","用户名或密码错误");
           req.getRequestDispatcher("login.jsp").forward(req,resp);
       }
   

8. 注册登录Servlet

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

9. 测试访问

3.登录功能优化

• 注销功能：移除Session，返回登录页面

  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
      //移除用户的Session
      req.getSession().removeAttribute(Constants.USER_SESSION);
      resp.sendRedirect(req.getContextPath()+"/login.jsp");
  }
  

• 注册登出Servlet

  <!--登出-->
  <servlet>
      <servlet-name>LogoutServlet</servlet-name>
      <servlet-class>com.java.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（过滤器）

  编写过滤器

  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
      HttpServletRequest request = (HttpServletRequest) servletRequest;
      HttpServletResponse response = (HttpServletResponse) servletResponse;
  
      //过滤器，从Session中获取用户
      User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);
      if (user == null){//被移除或者已经注销了，或者未登录
          response.sendRedirect(request.getContextPath()+"/error.jsp");
      }else{
          filterChain.doFilter(servletRequest,servletResponse);
      }
  }
  

  注册过滤器

  <!--用户登录过滤器-->
  <filter>
      <filter-name>SysFilter</filter-name>
      <filter-class>com.java.filter.SysFilter</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>SysFilter</filter-name>
      <url-pattern>/jsp/*</url-pattern>
  </filter-mapping>
  

4.密码修改

1. 导入前端素材

2. 编写UserDao接口

   public int updatePwd(Connection connection, int id, String userPassword)throws SQLException;
   

3. 编写UserDao接口实现类

   //修改当前用户密码
   public int updatePwd(Connection connection, int id, String userPassword) throws SQLException {
       PreparedStatement preparedStatement = null;
       int i = 0;
       if (connection != null) {
           String sql = "update smbms_user set userPassword=? where id=?";
           Object[] params = {userPassword, id};
           i = BaseDao.execute(connection, preparedStatement, sql, params);
           BaseDao.closeResource(connection, preparedStatement, null);
       }
       return i;
   }
   

4. 编写UserService接口

   public boolean updatePwd(int id, String userPassword);
   

5. 编写UserService接口实现类

   public boolean updatePwd(int id, String userPassword) {
       Connection connection = null;
       boolean flag = false;
       try {
           connection = BaseDao.getConnection();
           if (userDao.updatePwd(connection,id,userPassword)>0){
               flag = true;
           }
       } catch (SQLException e) {
           e.printStackTrace();
       }finally {
           BaseDao.closeResource(connection,null,null);
       }
       return flag;
   }
   

6. 实现复用，需要提取出方法

   //实现Servlet复用
   public class UserServlet extends HttpServlet {
       @Override
       protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
           String method = req.getParameter("method");
           if(method.equals("savepwd")&&method != null){
               this.updatePwd(req,resp);
           }else if(method.equals("pwdmodify")&&method != null){
               this.pwdModify(req,resp);
           }
       }
   
       @Override
       protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
           doGet(req, resp);
       }
       
       public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
           //从Session中拿到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){
               UserService userService = new UserServiceImpl();
               flag = userService.updatePwd(((User)o).getId(),newpassword);
               if (flag){
                   req.setAttribute("message","修改密码成功，请退出使用新密码登录");
                   //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 e) {
               e.printStackTrace();
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   }
   

7. Ajax验证旧密码是否正确

   oldpassword.on("blur",function(){
   		$.ajax({
   			type:"GET",
   			url:path+"/jsp/user.do",
   			data:{method:"pwdmodify",oldpassword:oldpassword.val()},
   			dataType:"json",
   			success:function(data){
   				if(data.result == "true"){//旧密码正确
   					validateTip(oldpassword.next(),{"color":"green"},imgYes,true);
   				}else if(data.result == "false"){//旧密码输入不正确
   					validateTip(oldpassword.next(),{"color":"red"},imgNo + " 原密码输入不正确",false);
   				}else if(data.result == "sessionerror"){//当前用户session过期，请重新登录
   					validateTip(oldpassword.next(),{"color":"red"},imgNo + " 当前用户session过期，请重新登录",false);
   				}else if(data.result == "error"){//旧密码输入为空
   					validateTip(oldpassword.next(),{"color":"red"},imgNo + " 请输入旧密码",false);
   				}
   			},
               error:function(data){
                   //请求出错
                   validateTip(oldpassword.next(),{"color":"red"},imgNo + " 请求错误",false);
               }
           });
   

8. 导入阿里巴巴的fastjson：Json工具，转换格式

   <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
   <dependency>
       <groupId>com.alibaba</groupId>
       <artifactId>fastjson</artifactId>
       <version>1.2.76</version>
   </dependency>
   

9. 编写后端代码

   //验证旧密码，Session中
   public void pwdModify(HttpServletRequest req, HttpServletResponse resp){
       Object o = req.getSession().getAttribute(Constants.USER_SESSION);
       String oldpassword = req.getParameter("oldpassword");
   
       //结果集
       Map<String,String> resultMap = new HashMap<String, String>();
   
       if (o == null){ //Session过期
           resultMap.put("result","sessionerror");
       }else if (oldpassword == null || oldpassword.length()==0){
           resultMap.put("result","error");
       }else{
           String userPassword = ((User) o).getUserPassword();
           if (oldpassword.equals(userPassword)){
               resultMap.put("result","true");
           }else{
               resultMap.put("result","false");
           }
       }
       try {
           resp.setContentType("application/json");
           PrintWriter writer = resp.getWriter();
           writer.write(JSONArray.toJSONString(resultMap));
           writer.flush();
           writer.close();
       } catch (IOException e) {
           e.printStackTrace();
       }
   }
   

5.用户管理实现

思路：

5.1 获取用户数量

1. UserDao

   //根据用户名或者角色查询用户总数
   public int getUserCount(Connection connection, String username, int userRole)throws SQLException;
   

2. UserDaoImpl

   //根据用户名或者角色查询用户总数
   public int getUserCount(Connection connection, String username, int userRole) throws SQLException {
       PreparedStatement preparedStatement = null;
       ResultSet resultSet = null;
       int count = 0;
   
       if (connection != null) {
           StringBuffer sql = new StringBuffer();
           sql.append("select count(1) as count from smbms_user u, smbms_role r where u.userRole = r.id");
           ArrayList<Object> list = new ArrayList<Object>(); //存放参数
   
           if (!StringUtils.isNullOrEmpty(username)){
               sql.append(" and u.userName like ?");
               list.add("%"+username+"%"); //index 0
           }
   
           if (userRole>0){
               sql.append(" and u.userRole = ?");
               list.add(userRole); //index 1
           }
   
           //将list转换为数组
           Object[] objects = list.toArray();
   
           resultSet = BaseDao.execute(connection, preparedStatement,resultSet, sql.toString(), objects);
           if (resultSet.next()){
               count = resultSet.getInt("count");//从结果中获取最终的数量
           }
           BaseDao.closeResource(null, preparedStatement, resultSet);
       }
       return count;
   }
   

3. UserService

   //根据用户名或者角色查询用户总数
   public int getUserCount(String username, int userRole);
   

4. UserServiceImpl

   public int getUserCount(String username, int userRole) {
       Connection connection = null;
       int count = 0;
       try {
           connection = BaseDao.getConnection();
           count = userDao.getUserCount(connection, username, userRole);
       } catch (SQLException e) {
           e.printStackTrace();
       }finally {
           BaseDao.closeResource(connection,null,null);
       }
       return count;
   }
   

5.2 获取用户列表

1. UserDao

   //获取用户列表
   public List<User> getUserList(Connection connection, String username, int userRole, int currentPageNo, int pageSize) throws  SQLException;
   

2. UserDaoImpl

   //获取用户列表
   public List<User> getUserList(Connection connection, String username, int userRole, int currentPageNo, int pageSize) throws SQLException {
       PreparedStatement preparedStatement = null;
       ResultSet resultSet = null;
       int count = 0;
       List<User> userList = new ArrayList<User>();
   
       if (connection != null) {
           StringBuffer sql = new StringBuffer();
           sql.append("select u.*,r.roleName as userRoleName from smbms_user u, smbms_role r where u.userRole = r.id");
           ArrayList<Object> list = new ArrayList<Object>(); //存放参数
   
           if (!StringUtils.isNullOrEmpty(username)){
               sql.append(" and u.userName like ?");
               list.add("%"+username+"%"); //index 0
           }
   
           if (userRole>0){
               sql.append(" and u.userRole = ?");
               list.add(userRole); //index 1
           }
           sql.append(" order by creationDate DESC limit ?,?");
           currentPageNo = (currentPageNo-1)*pageSize;
           list.add(currentPageNo);
           list.add(pageSize);
   
           //将list转换为数组
           Object[] objects = list.toArray();
   
           resultSet = BaseDao.execute(connection, preparedStatement,resultSet, sql.toString(), objects);
           if (resultSet.next()){
               User _user = new User();
               _user.setId(resultSet.getInt("id"));
               _user.setUserCode(resultSet.getString("userCode"));
               _user.setUserName(resultSet.getString("userName"));
               _user.setGender(resultSet.getInt("gender"));
               _user.setBirthday(resultSet.getDate("birthday"));
               _user.setPhone(resultSet.getString("phone"));
               _user.setUserRole(resultSet.getInt("userRole"));
               _user.setUserRoleName(resultSet.getString("userRoleName"));
               userList.add(_user);
           }
           BaseDao.closeResource(null, preparedStatement, resultSet);
       }
       return userList;
   }
   

3. UserService

   //获取用户列表
   public List<User> getUserList(String username, int userRole, int currentPageNo, int pageSize);
   

4. UserServiceImpl

   //获取用户列表
   public List<User> getUserList(String username, int userRole, int currentPageNo, int pageSize) {
       Connection connection = null;
       List<User> userList = null;
       try {
           connection = BaseDao.getConnection();
           userList = userDao.getUserList(connection, username,userRole,currentPageNo,pageSize);
       } catch (Exception e) {
           e.printStackTrace();
       }finally{
           BaseDao.closeResource(connection, null, null);
       }
       return userList;
   }
   

5.3 获取角色列表

为了职责统一，可以把角色的操作单独放在一个包中，和pojo对应

1. RoleDao

   //获取角色列表
   public List<Role> getRoleList(Connection connection) throws SQLException;
   

2. RoleDaoImpl

   //获取角色列表
   public List<Role> getRoleList(Connection connection) throws SQLException {
       PreparedStatement preparedStatement = null;
       ResultSet resultSet = null;
       List<Role> roleList = new ArrayList<Role>();
   
       if(connection != null){
           String sql = "select * from smbms_role";
           Object[] params = {};
           resultSet = BaseDao.execute(connection, preparedStatement, resultSet, sql, params);
           while (resultSet.next()){
               Role _role = new Role();
               _role.setId(resultSet.getInt("id"));
               _role.setRoleCode(resultSet.getString("roleCode"));
               _role.setRoleName(resultSet.getString("roleName"));
               roleList.add(_role);
           }
           BaseDao.closeResource(null, preparedStatement, resultSet);
       }
       return roleList;
   }
   

3. RoleService

   //获取角色列表
   public List<Role> getRoleList();
   

4. RoleServiceImpl

   public List<Role> getRoleList() {
       Connection connection = null;
       List<Role> roleList = null;
       try {
           connection = BaseDao.getConnection();
           roleList = roleDao.getRoleList(connection);
       } catch (SQLException e) {
           e.printStackTrace();
       }finally {
           BaseDao.closeResource(connection,null,null);
       }
       return roleList;
   }
   

5.4 用户显示Servlet

1. 获取用户前端的数据

2. 判断请求是否需要执行，看参数的值判断

3. 为了实现分页，需要算出当前页面、总页面和页面大小

4. 用户列表展示

5. 返回前端

   //代码复用
   protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
           String method = req.getParameter("method");
       	....
   		else if (method.equals("query")&&method != null){
               this.query(req,resp);
           }
   }
   //用户列表
   public void query(HttpServletRequest req, HttpServletResponse resp){
   
       //查询用户列表
       String queryUserName = req.getParameter("queryname");
       String temp = req.getParameter("queryUserRole");
       String pageIndex = req.getParameter("pageIndex");
       int queryUserRole = 0;
   
       //获取用户列表
       UserServiceImpl userService = new UserServiceImpl();
       List<User> userList = null;
   
       //第一次走这个请求，一定是第一，页面大小固定
       int  currentPageNo = 1;
   
       if (queryUserName == null){
           queryUserName = "";
       }
       if (temp != null && !temp.equals("")){
           queryUserRole = Integer.parseInt(temp);
       }
       if (pageIndex != null){
           currentPageNo = Integer.parseInt(pageIndex);
       }
   
       //获取用户的总数（分页）
       int totalCount = userService.getUserCount(queryUserName, queryUserRole);
   
       //总页数支持
       PageSupport pageSupport = new PageSupport();
       pageSupport.setCurrentPageNo(currentPageNo);
       pageSupport.setPageSize(Constants.pageSize);
       pageSupport.setTotalCount(totalCount);
   
       int totalPageCount = pageSupport.getTotalPageCount();
   
       //控制首页和尾页
       //如果页面要小于1，就显示第一页的内容
       if (totalPageCount < 1){
           currentPageNo = 1;
       }else if (currentPageNo > totalPageCount){ //当前页大于最后一页
           currentPageNo = totalPageCount;
       }
   
       //获取用户列表展示
       userList = userService.getUserList(queryUserName, queryUserRole, currentPageNo, Constants.pageSize);
       req.setAttribute("userList",userList);
   
       RoleServiceImpl roleService = new RoleServiceImpl();
       List<Role> roleList = roleService.getRoleList();
       req.setAttribute("roleList",roleList);
       req.setAttribute("totalPageCount",totalPageCount);
       req.setAttribute("totalCount",totalCount);
       req.setAttribute("currentPageNo",currentPageNo);
   
       //返回前端
       try {
           req.getRequestDispatcher("userlist.jsp").forward(req,resp);
       } catch (ServletException e) {
           e.printStackTrace();
       } catch (IOException e) {
           e.printStackTrace();
       }
   }
   

6.其他功能

• 其他功能类似查询功能，基本都是数据库的操作，参考项目源代码

原文链接:https://blog.csdn.net/TvTToT/article/details/117261032