JavaWeb实现smbms项目核心功能

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

   1. 数据库配置文件

      driver=com.mysql.cj.jdbc.Driver
      url=jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=UTF-8&useSSL=true&setServiceTime=GMT
      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;
          }
      }
      

   3. 编写字符编码过滤器

8. 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
   
       @Override
       protected 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);
           }
       }
   
       @Override
       protected 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 {
    @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(req.getContextPath()+"/login.jsp");//返回登录页面
    }
    @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.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！

   @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);
       }
   }
   
   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Session
               req.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Session
               req.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-userList
   public 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    10
   
           sql.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-userList
   public 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Dao
    private 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