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JavaWeb实现smbms项目核心功能

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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,
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

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