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JavaWeb实现smbms项目核心功能

2022-05-09 分类：Java开发 评论(0)

SMBMS

数据库：

项目如何搭建？

考虑使用不使用Maven？依赖，Jar

1、项目搭建准备工作

  1. 搭建一个maven web项目

  2. 配置Tomcat

  3. 测试项目是否能够跑起来

  4. 导入项目中会遇到的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：表-类映射

  7. 编写基础公共类

    数据库配置文件

    driver=com.mysql.cj.jdbc.Driverurl=jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=UTF-8&useSSL=true&setServiceTime=GMTusername=rootpassword=123456

  8. 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，类加载的时候就初始化了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;}//编写查询公共类public static ResultSet execute(Connection connection,String sql,Object[] params,ResultSet resultSet,PreparedStatement preparedStatement) 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，但是我们的数组是从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, String sql, Object[] params, PreparedStatement preparedStatement) throws SQLException {preparedStatement = connection.prepareStatement(sql);for (int i = 0; i < params.length; i++) {//setObject，占位符从1开始，但是我们的数组是从0开始！preparedStatement.setObject(i+1,params[i]);}int updateRows = preparedStatement.executeUpdate();return updateRows;}//释放资源public static boolean closeResource(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;}}

  9. 编写字符编码过滤器

  • 导入静态资源

    • 2、登录功能实现

    1. 编写前端页面

    2. 设置首页

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

    3. 编写dao层得到用户登录的接口

      DAO：data access object

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

    4. 编写dao接口的实现类

      public class UserDaoImpl implements UserDao{public User getLoginUser(Connection connection, String userCode) throws SQLException {PreparedStatement pstm = null;ResultSet rs = null;User user = null;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("userName"));user.setUserPassword(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(null,pstm,rs);}return user;}}

    5. 业务层接口

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

    6. 业务层实现类

      public class UserServiceImpl implements UserService {//业务层都会调用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;connection = BaseDao.getConnection();try {user = userDao.getLoginUser(connection, userCode);} catch (SQLException e) {e.printStackTrace();} finally {BaseDao.closeResource(connection, null, null);}return user;}}

    7. 编写Servlet

      public class LoginServlet extends HttpServlet {//Servlet：控制层，调用业务层代码@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println("LoginServlet--start....");//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；UserService userService = new UserServiceImpl();User user = userService.login(userCode, userPassword); //这里已经把登录的人给查出来了if (user!=null){ //查有此人，可以登录//将用户的信息放到Session中；req.getSession().setAttribute(Constants.USER_SESSION,user);//跳转到主页resp.sendRedirect("jsp/frame.jsp");}else {//查无此人，无法登录//转发回登录页面，顺带提示它，用户名或者密码错误req.setAttribute("error","用户名或者密码不正确");req.getRequestDispatcher("login.jsp").forward(req,resp);}}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req, resp);}}

    8. 注册Servlet

      <!--Servlet--><servlet><servlet-name>LoginServlet</servlet-name><servlet-class>com.kuang.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，确保以上功能成功！

    3、登录功能优化

    注销功能：

    思路：移除Session，返回登录页面

    public class LogoutServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//移除用户的Constants.USER_SESSIONreq.getSession().removeAttribute(Constants.USER_SESSION);resp.sendRedirect(req.getContextPath()+"/login.jsp");//返回登录页面}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req, resp);}}

    注册xml

    <servlet><servlet-name>LogoutServlet</servlet-name><servlet-class>com.kuang.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

    编写一个过滤器并注册

    public class SysFilter implements Filter {public void init(FilterConfig filterConfig) throws ServletException {}public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {HttpServletRequest request = (HttpServletRequest) req;HttpServletResponse response = (HttpServletResponse) resp;//过滤器，从Session中获取用户，User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);if (user==null){ //已经被移除或者注销了，或者未登录response.sendRedirect("/smbms/error.jsp");}else {chain.doFilter(req,resp);}}public void destroy() {}}
    <!--用户登录过滤器--><filter><filter-name>SysFilter</filter-name><filter-class>com.kuang.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！

    4、密码修改

    1. 导入前端素材

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

    2. 写项目，建议从底层向上写

    3. UserDao接口

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

    4. UserDao接口实现类

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

    5. UserService层

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

    6. UserService实现类

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

    7. Servlet记得实现复用，需要提取出方法！

      @Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String method = req.getParameter("method");if (method.equals("savepwd")&&method!=null){this.updatePwd(req, resp);}}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");System.out.println("UserServlet"+newpassword);boolean flag = false;//if (o!=null && !StringUtils.isNullOrEmpty(newpassword)){if (o!=null && newpassword!=null){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Sessionreq.getSession().removeAttribute(Constants.USER_SESSION);}else {req.setAttribute("message","密码修改失败");//密码修改成功，移除当前Session}}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();}}
      <servlet><servlet-name>UserServlet</servlet-name><servlet-class>com.kuang.servlet.user.UserServlet</servlet-class></servlet><servlet-mapping><servlet-name>UserServlet</servlet-name><url-pattern>/jsp/user.do</url-pattern>

    8. 测试

    优化密码修改使用Ajax；

    1. 阿里巴巴的fastjson

      <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.79</version></dependency>

    2. 后台代码修改

      //修改密码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");System.out.println("UserServlet"+newpassword);boolean flag = false;//if (o!=null && !StringUtils.isNullOrEmpty(newpassword)){if (o!=null && newpassword!=null){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Sessionreq.getSession().removeAttribute(Constants.USER_SESSION);}else {req.setAttribute("message","密码修改失败");//密码修改成功，移除当前Session}}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();}}//验证旧密码，session中有用户的密码public void pwdModify(HttpServletRequest req, HttpServletResponse resp){//从Session里面拿oldpassword；Object o = req.getSession().getAttribute(Constants.USER_SESSION);String oldpassword = req.getParameter("oldpassword");//万能的Map : 结果集HashMap<String, String> resultMap = new HashMap<String,String>();if (o==null){ //Session失效了，session过期了resultMap.put("result","sessionerror");}else if (StringUtils.isNullOrEmpty(oldpassword)){ //输入的密码为空resultMap.put("result","error");}else {String userPassword = ((User) o).getUserPassword(); //Session中用户的密码if (oldpassword.equals(userPassword)){resultMap.put("result","true");}else {resultMap.put("result","false");}}try {resp.setContentType("application/json");PrintWriter writer = resp.getWriter();//JSONArray 阿里巴巴的JSON工具类，转换格式/*resultMap = ["result","sessionerror","result","error"]Json格式 = {key:value}*/writer.write(JSONArray.toJSONString(resultMap));writer.flush();writer.close();} catch (IOException e) {e.printStackTrace();}}

    3. 测试

    5、用户管理实现

    思路：

    1. 导入分页的工具类

    2. 用户列表页面导入

      userlist.jsp

      rollpage.jsp

    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【最难理解的SQL】public int getUserCount(Connection connection, String username, int userRole) throws SQLException {PreparedStatement pstm = null;ResultSet rs = 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>();//存放我们的参数if (!StringUtils.isNullOrEmpty(username)){ //拼接sql语句sql.append(" and u.userName like ?");list.add("%"+username+"%"); //index:0}if (userRole>0){sql.append(" and u.userRole = ?");list.add(userRole); //index:1}//怎么把list转换为数组Object[] params = list.toArray();System.out.println("UserDaoImpl->getUserCount"+sql.toString()); //输出最后完整的SQL语句rs = BaseDao.execute(connection, pstm, null, sql.toString(), params);if (rs.next()){count = rs.getInt("count");//从结果集中获取最终的数量}BaseDao.closeResource(null,pstm,rs);}return count;}

    3. UserService

      //查询记录数public int getUserCount(String username, int userRole);

    4. UserServiceImpl

      //查询记录数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;}

    2、获取用户列表

    1. userdao

      //通过条件查询-userListpublic List<User> getUserList(Connection connection, String username, int userRole, int currentPageNo, int pageSize) throws Exception;

    2. userdaoImpl

      public List<User> getUserList(Connection connection, String username, int userRole, int currentPageNo, int pageSize) throws Exception {PreparedStatement pstm = null;ResultSet rs = null;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");List<Object> list = new ArrayList<Object>();//存放我们的参数if (!StringUtils.isNullOrEmpty(username)){ //拼接sql语句sql.append(" and u.userName like ?");list.add("%"+username+"%"); //index:0}if (userRole>0){sql.append(" and u.userRole = ?");list.add(userRole); //index:1}//在数据库中，分页使用  limit startIndex,pageSize;  总数//当前页    （当前页-1）*页面大小//0,5    1    0    01234//5,5    2    5    56789//10,5   3    10sql.append(" order by creationDate DESC limit ?,?");currentPageNo = (currentPageNo-1)*pageSize;list.add(currentPageNo);list.add(pageSize);//怎么把list转换为数组Object[] params = list.toArray();System.out.println("sql-->"+sql.toString()); //输出最后完整的SQL语句rs = BaseDao.execute(connection, pstm, null, sql.toString(), params);while (rs.next()){User user = new User();user.setId(rs.getInt("id"));user.setUserCode(rs.getString("userCode"));user.setUserName(rs.getString("userName"));user.setGender(rs.getInt("gender"));user.setBirthday(rs.getDate("birthday"));user.setPhone(rs.getString("phone"));user.setUserRole(rs.getInt("userRole"));user.setUserRoleName(rs.getString("userRoleName"));userList.add(user);}BaseDao.closeResource(null,pstm,rs);}return userList;}

    3. userService

      //通过条件查询-userListpublic List<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize);

    4. userServiceImpl

      public List<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize) {Connection connection = null;List<User> userList = null;try {connection = BaseDao.getConnection();userList = userDao.getUserList(connection, queryUserName, queryUserRole,currentPageNo,pageSize);} catch (Exception e) {e.printStackTrace();} finally {BaseDao.closeResource(connection,null,null);}return userList;}

    3、获取角色操作

    为了我们职责统一，可以把角色的操作单独放在一个包中，和POJO类对应

    RoleDao

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

    RoleDaoImpl

    public List<Role> getRoleList(Connection connection) throws SQLException {PreparedStatement pstm = null;ResultSet resultSet = null;ArrayList<Role> roleList = new ArrayList<Role>();if (connection!=null){String sql = "select * from smbms_role";Object[] params = {};resultSet = BaseDao.execute(connection, pstm, 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,pstm,resultSet);}return roleList;}

    RoleService

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

    RoleServiceImpl

    public class RoleServiceImpl implements RoleService{//引入Daoprivate RoleDao roleDao = null;public RoleServiceImpl(){roleDao = new RoleDaoImpl();}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;}}

    4、用户显示的Servlet

    1. 获取用户前端的数据（查询）
    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，需要计算出当前页面和总页面，页面大小…
    4. 用户列表展示
    5. 返回前端
    //重点，难点public void query(HttpServletRequest req, HttpServletResponse resp){//查询用户列表//从前端获取数据：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，页面大小固定的；int pageSize = 5;//可以把这个写到配置文件中，方便后期修改；int currentPageNo = 1;if (queryUserName == null){queryUserName = ""; //不手动赋值会产生空指针异常}if (temp != null && !temp.equals("")){queryUserRole = Integer.parseInt(temp); //给查询赋值！0,1,2,3}if (pageIndex != null){currentPageNo = Integer.parseInt(pageIndex);}//获取用户的总数（分页：上一页，下一页的情况）int totalCount = userService.getUserCount(queryUserName,queryUserRole);//总页数支持PageSupport pageSupport = new PageSupport();pageSupport.setCurrentPageNo(currentPageNo);pageSupport.setPageSize(pageSize);pageSupport.setTotalCount(totalCount);int totalPageCount = pageSupport.getTotalPageCount(); //总共有几页//控制首页和尾页//如果页面要小于1了，就显示第一页的东西if (totalPageCount<1){currentPageNo = 1;}else if (currentPageNo>totalPageCount){ //当前页面大于了最后一项；currentPageNo = totalPageCount;}//获取用户列表展示userList = userService.getUserList(queryUserName, queryUserRole, currentPageNo, pageSize);req.setAttribute("userList",userList);RoleServiceImpl roleService = new RoleServiceImpl();List<Role> roleList = roleService.getRoleList();req.setAttribute("roleList",roleList);req.setAttribute("totalCount",totalCount);req.setAttribute("currentPageNo",currentPageNo);req.setAttribute("totalPageCount",totalPageCount);req.setAttribute("queryUserName",queryUserName);req.setAttribute("queryUserRole",queryUserRole);//返回前端try {req.getRequestDispatcher("userlist.jsp").forward(req,resp);} catch (ServletException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}

    小黄鸭调试法

    6、SMBMS架构分析

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