SMBMS订单管理系统(手把手教细致讲解实现全过程) (七)

wuchangjian2021-11-30 18:27:38编程学习

实现用户管功能
在这里插入图片描述
刚刚访问密码直接走前端

现在要发起请求走Servlet,Servlet处理后返回前端页面
Servlet

  • 处理请求
  • 调用业务
  • 返回页面

业务要查询用户列表,查询角色列表,为了实现分页,需查询pageSize总数。查询从Service层到Dao层,Dao层从数据库里面查

1、导入分页的工具类

2、用户列表页面导入
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类一一对应

1、获取用户数量


UserDao

 //查询用户总数
 	public int getUserCount(Connection connection,String username,int userRole) throws SQLException;
//通过条件查询-userlist
	public List<User> getUserList(Connection connection,String userName,int userRole,int currentPageNo,int pageSize)throws Exception;

  • UserDaoImpl
//根据用户名或者角色查询用户总数
    public int getUserCount(Connection connection, String username, int userRole) throws SQLException {
        PreparedStatement 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>();
            if(!StringUtils.isNullOrEmpty(username)){
                sql.append(" and u.userName like ?");
                list.add("%"+username+"%");
            }
            if(userRole>0){
                sql.append(" and u.userRole= ?");
                list.add(userRole);
            }
            //list转化为数组
            Object[] params=list.toArray();
            System.out.println("UserDaoImpl->getUserCount:"+sql.toString());
            rs = BaseDao.execute(connection, pstm, rs, sql.toString(), params);
            if(rs.next()){
                //从结果集中获取最终的数量
             count = rs.getInt("count");
            }
            BaseDao.closeResource(null,pstm,rs);
        }
        return count;
    }

    public List<User> getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws Exception {
        // TODO Auto-generated method stub
        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>();
            if(!StringUtils.isNullOrEmpty(userName)){
                sql.append(" and u.userName like ?");
                list.add("%"+userName+"%");
            }
            if(userRole > 0){
                sql.append(" and u.userRole = ?");
                list.add(userRole);
            }
            sql.append(" order by creationDate DESC limit ?,?");
            currentPageNo = (currentPageNo-1)*pageSize;
            list.add(currentPageNo);
            list.add(pageSize);

            Object[] params = list.toArray();
            System.out.println("sql ----> " + sql.toString());
            rs = BaseDao.execute(connection, pstm, rs, 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;
    }
  • UserService
    //查询记录数
    public int getUserCount(String userName,int userRole);
    public List<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize);
  • 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;
    }
    public List<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize) {
        // TODO Auto-generated method stub
        Connection connection = null;
        List<User> userList = null;
        System.out.println("queryUserName ---- > " + queryUserName);
        System.out.println("queryUserRole ---- > " + queryUserRole);
        System.out.println("currentPageNo ---- > " + currentPageNo);
        System.out.println("pageSize ---- > " + pageSize);
        try {
            connection = BaseDao.getConnection();
            userList = userDao.getUserList(connection, queryUserName,queryUserRole,currentPageNo,pageSize);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            BaseDao.closeResource(connection, null, null);
        }
        return userList;
    }
     @Test
    public void test1(){
        UserServiceImpl userService = new UserServiceImpl();
        int userCount=userService.getUserCount(null,0);
        System.out.println(userCount);
    }

2、获取角色数量

在Dao层和Service层都新增role部分
在这里插入图片描述

RoleDao

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

RoleDaoImpl

package com.lding.dao.role;

import com.lding.dao.BaseDao;
import com.lding.pojo.Role;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * @program: SMBMS
 * @description:
 * @author: 王丁
 * @date: 2021-11-09 15:39
 **/
public class RoleDaoImpl implements RoleDao{
    public List<Role> getRoleList(Connection connection) throws SQLException {

            PreparedStatement pstm = null;
            ResultSet rs = null;
            ArrayList<Role> roleList = new ArrayList<Role>();
            if (connection != null) {
                String sql = "select * from smbms_role";
                Object[] params = {};
                rs = BaseDao.execute(connection, pstm, rs, sql, params);
                while (rs.next()) {
                    Role _role = new Role();
                    _role.setId(rs.getInt("id"));
                    _role.setRoleCode(rs.getString("roleCode"));
                    _role.setRoleName(rs.getString("roleName"));
                    roleList.add(_role);
                }
                BaseDao.closeResource(null, pstm, rs);
            }
            return roleList;
    }
}

RoleService

public interface RoleService {
    //获取角色列表
    public List<Role> getRoleList();
}

RoleServiceImpl

public class RoleServiceImpl implements RoleService {
    //引入Dao
    private RoleDao roleDao;
    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) {

        }finally {
            BaseDao.closeResource(connection,null,null);
        }
        return roleList;
    }
    @Test
    public void test(){
        RoleServiceImpl roleService=new RoleServiceImpl();
        List<Role> roleList=roleService.getRoleList();
        for(Role role:roleList){
            System.out.println(role.getRoleName());
        }
    }
}

和之前的实现思路一样,我们先在Dao层实现对数据库中信息的提取,然后在Service层直接调用Dao层中的方法

以角色查询为例,在DaoImpl实现方法中创建PrepareStatement预编译对象,rs结果集对象,
roleList存储角色列表,通过传过来的连接,编写查询role的sql语句,然后执行Dao的execute方法
在这里插入图片描述
得到rs结果集后遍历rs结果集,取出每个role对象,存储到roleList,然后返回roleList

RoleServiceImpl直接调用Dao层中的getRoleList方法
在service层创建与数据库的连接,然后调用getRoleList方法得到查询结果 最后关闭资源
在这里插入图片描述
在这里插入图片描述
在这里插入图片描述
拿到前端列表后,将所有数据通过req.setAttribute的方式存入属性中,前端也可以通过这个属性获取。
最后通过请求转发req.getRequestDispatcher(“userlist.jsp”).forward(req,resp);返回前端页面。
UserServlet完整代码

package com.lding.servlet.user;

import com.alibaba.fastjson.JSONArray;
import com.lding.pojo.Role;
import com.lding.pojo.User;
import com.lding.service.role.RoleService;
import com.lding.service.role.RoleServiceImpl;
import com.lding.service.user.UserServiceImpl;
import com.lding.util.Constants;
import com.lding.util.PageSupport;
import com.mysql.jdbc.StringUtils;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @program: SMBMS
 * @description:
 * @author: 王丁
 * @date: 2021-11-06 20:49
 **/
public class UserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String method = req.getParameter("method");
        if(method!=null&&method.equals("savepwd")){
            updatePwd(req,resp);
        }else if(method!=null&&method.equals("pwdmodify")){
            pwdModify(req,resp);
        }else if(method.equals("query")&&method!=null){
            this.query(req,resp);
        }
    }
    //重点难点
    public void query(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //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");
        List<User> userList=null;
        int queryUserRole=0;
        //获取用户列表
        UserServiceImpl userService=new UserServiceImpl();
        //第一次走这个请求,一定是第一页,页面大小是固定的
        int pageSize=5; //可以把这个写在配置文件中,方便后期修改
        int currentPageNo=1;
        if(queryUserName==null){
            queryUserName="";
        }
        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)
        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();
        //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(currentPageNo<1){
            currentPageNo=1;
        }else if(currentPageNo>totalPageCount){
            currentPageNo=totalPageCount;
        }
        //获取用户列表展示
        userList = userService.getUserList(queryUserName, queryUserRole, currentPageNo, pageSize);
        req.setAttribute("userList",userList);
        //拿到角色列表
        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
        req.getRequestDispatcher("userlist.jsp").forward(req,resp);
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
    public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
        //获取参数往上提交
        //从Session中拿用户ID
        Object user = req.getSession().getAttribute(Constants.USER_SESSION);
        String newpassword = req.getParameter("newpassword");
        boolean flag=false;
        if(user!=null&&newpassword!=null){
            UserServiceImpl userService = new UserServiceImpl();
            flag= userService.updatePwd(((User) user).getId(), newpassword);
            if(flag){
                req.setAttribute("message","修改密码成功,请退出重新登陆");
                //密码修改成功 移除当前Session
                req.getSession().removeAttribute(Constants.USER_SESSION);
                //过滤器自动判断Session为null 重新回登陆页面
            }else{
                req.setAttribute("message","密码修改失败");
            }
        }else{
            req.setAttribute("message","新密码有问题");
        }
        try {
            req.getRequestDispatcher("pwdmodify.jsp").forward(req,resp);
        } catch (ServletException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public void pwdModify(HttpServletRequest req, HttpServletResponse resp){
        //从Session里面拿ID
        Object o=req.getSession().getAttribute(Constants.USER_SESSION);
        String oldpassword=req.getParameter("oldpassword");
        //万能的Map :结果集
        Map<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)){
            resultMap.put("result","error");
        }else{
            String userPassword=((User)o).getUserPassword();//Session中的用户的密码
            if(oldpassword.equals(userPassword)){
                resultMap.put("result","true");
            }else{
                resultMap.put("result","false");
            }
        }
        resp.setContentType("application/json");
        try {
            PrintWriter writer=resp.getWriter();
            //JSONArray 阿里巴巴的JSON工具类,转换格式
            /*
                resultMap=["result","sessionerror"]
                转化为Json格式={key:value}
             */
            writer.write(JSONArray.toJSONString(resultMap));
            writer.flush();
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

} 

后面其他功能都和用户管理的类似,我就不完全粘代码了,有需要完整工程的在评论区评论发给您~

如果对您有帮助,免费的三连点一个,感谢🙏~

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