JavaWeb实现smbms项目核心功能

简介: 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 搭建一个maven web项目 配置Tomcat 测试项目是否能够跑起来 导入项目中会遇到的jar包; jsp,Servlet,mysql驱动,jstl,standard... 创建项目包结构 编写实

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


  1. 配置Tomcat


  1. 测试项目是否能够跑起来


  1. 导入项目中会遇到的jar包;


jsp,Servlet,mysql驱动,jstl,standard...

  1. 创建项目包结构



  1. 编写实体类;
    ORM映射:表-类映射


  1. 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


  1. 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;
    }
}


  1. 编写字符编码过滤器


  1. 导入静态资源


2、登录功能实现



  1. 编写前端页面


  1. 设置首页


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


  1. 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;


  1. 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;
    }
}


  1. 业务层接口


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


  1. 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;
    }
}


  1. 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);
    }
}


  1. 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>


  1. 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>


  1. 写项目,建议从底层向上写



  1. UserDao接口


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


  1. 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;
}


  1. UserService层


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


  1. 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;
}


  1. 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>


  1. 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>


  1. 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();
    }
}


  1. 测试


5、用户管理实现


思路:



  1. 导入分页的工具类


  1. 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;


  1. 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;
}


  1. UserService


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


  1. 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;


  1. 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;
}


  1. userService


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


  1. 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)


  1. 判断请求是否需要执行,看参数的值判断


  1. 为了实现分页,需要计算出当前页面和总页面,页面大小...


  1. 用户列表展示


  1. 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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