• 超适合练手的一套JavaWeb项目 （超市后台管理系统）

    GIF动态图演示

    在这里插入图片描述

    百度百度网盘提取项目 带数据库！[链接]:https://pan.baidu.com/s/13F2rxszZRLGDt9pr6ixYUg提取码：关注私信我发送！

    一、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.导入项目中遇到的jar包
    • 5.创建项目结构
      在这里插入图片描述

    6.编写实体类

    ORM映射：表类映射

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    7.编写基础公共类

    1.数据库配置文件

    db.properties文件代码

    driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=utf-8
username=root
password=111111

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    2.编写数据库的公共类

    java代码

    package com.syj.dao;

import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

//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");
    }

    //获取数据库的链接
    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 {
       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;
    }

    //编写增删改查公共方法
    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;
    }

    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;
    }
}

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    3.编写字符编码过滤器

    8.导入静态资源

    二、登录功能实现

    1.编写前端页面

    2.设置欢迎界面

    xml代码

    
    
        login.jsp
    

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    3.编写dao层登录用户的接口

    java dao层接口代码

    package com.syj.dao.user;
import com.syj.entity.User;
import java.sql.Connection;
import java.sql.SQLException;
public interface UserDao {
    //得到登录的用户
    public User getLoginUser(Connection connection,String userCode) throws SQLException;
}

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    4.编写dao接口的实现类

    java dao接口的实现类代码

    package com.syj.dao.user;
import com.syj.dao.BaseDao;
import com.syj.entity.User;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class UserDaoImpl implements UserDao{
    //得到要登录的用户
    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;
    }
}

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    5.业务层接口

    java service接口代码

    package com.syj.service.user;
import com.syj.entity.User;
public interface UserService {
        //用户登录
    public User login(String userCode,String password);
}

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    6.业务层实现类

    java serviceImpl实现类代码

    package com.syj.service.user;
import com.syj.dao.BaseDao;
import com.syj.dao.user.UserDao;
import com.syj.dao.user.UserDaoImpl;
import com.syj.entity.User;
import java.sql.Connection;
import java.sql.SQLException;
public class UserServiceImpl implements UserService{

    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;
    }

}

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    7.编写Servlet

    java 代码

    package com.syj.servlet;
import com.syj.entity.User;
import com.syj.service.user.UserService;
import com.syj.service.user.UserServiceImpl;
import com.syj.util.Constants;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class LoginServlet extends HttpServlet {
    
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String userCode = req.getParameter("userCode");
        String userPassword = req.getParameter("userPassword");

        UserService userService = new UserServiceImpl();
        User user = userService.login(userCode, userPassword);

        if(user != null){
            req.getSession().setAttribute(Constants.USER_SESSION,user);
            resp.sendRedirect("jsp/frame.jsp");
        }else{
            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);
    }
}

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    8.注册servlet

    xml代码

    
        LoginServlet
        com.syj.servlet.LoginServlet
    
    
        LoginServlet
        /login.do
    

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    9.测试访问确保以上功能成功

    三、登陆功能优化

    注销功能：

    思路：移除Session,返回登录界面
    java servlet代码

    package com.syj.servlet;
import com.syj.util.Constants;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class LogoutServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
      req.getSession().removeAttribute(Constants.USER_SESSION);
      resp.sendRedirect("/login.jsp");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

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    xml 代码

    
    
        LogoutServlet
        com.syj.servlet.LogoutServlet
    
    
        LogoutServlet
        /jsp/logout.do
    

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    四、登录拦截优化

    编写一个过滤器并注册

    java 代码

    package com.syj.filter;

import com.syj.entity.User;
import com.syj.util.Constants;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

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;

        User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);

        if(user==null){
            response.sendRedirect("/smbms/error.jsp");
        }else{
            chain.doFilter(req,resp);
        }


    }

    public void destroy() {

    }
}

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    xml 代码

       
    
        SysFilter
        com.syj.filter.SysFilter
    
    
        SysFilter
        /jsp/*
    

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    测试，登录，注销，权限，以上功能都要保证执行成功

    五、密码修改

    1.导入前端素材

    pwdmodify.jsp

    密码修改

    2.写项目，建议从底层向上写

    3.UserDao接口

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

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    4.UserDao接口实现类

    //修改用户密码
    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;
    }

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    5.UserService层

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

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    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 false;
    }

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    7. servlet控制器层

    记得实现复用，需要提取方法

     @Override
package com.mario.servlet;

import com.mario.entity.User;
import com.mario.service.user.UserService;
import com.mario.service.user.UserServiceImpl;
import com.mario.util.Constants;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class UserServlet extends HttpServlet {

    @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);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }

    public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
        Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
        String newpassword = req.getParameter("newpassword");

        System.out.println(newpassword);

        boolean flag = false;

        if(obj != null && newpassword != null){
            UserService userService = new UserServiceImpl();
            flag = userService.updatePwd(((User) obj).getId(), newpassword);
            if(flag){
                req.setAttribute("message","修改密码成功");
                req.getSession().removeAttribute(Constants.USER_SESSION);
            }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();
        }
    }
}

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    8. 测试

    优化密码修改使用Ajax

    1.阿里巴巴的fastjson

    pom.xml

    
      com.alibaba
      fastjson
      1.2.61
    

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    2.后台修改的代码

    package com.mario.servlet;
import com.alibaba.fastjson.JSONArray;
import com.mario.entity.User;
import com.mario.service.user.UserService;
import com.mario.service.user.UserServiceImpl;
import com.mario.util.Constants;
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.Map;

public class UserServlet extends HttpServlet {

    @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);
        }else if(method.equals("pwdmodify") && method != null){
            this.pwdModify(req,resp);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }

    //修改密码
    public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
        Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
        String newpassword = req.getParameter("newpassword");

        System.out.println(newpassword);

        boolean flag = false;

        if(obj != null && newpassword != null){
            UserService userService = new UserServiceImpl();
            flag = userService.updatePwd(((User) obj).getId(), newpassword);
            if(flag){
                req.setAttribute("message","修改密码成功");
                req.getSession().removeAttribute(Constants.USER_SESSION);
            }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();
        }
    }

    //验证旧密码,session中有用户的密码
    public void pwdModify(HttpServletRequest req, HttpServletResponse resp){
        Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
        String oldpassword = req.getParameter("oldpassword");

        Map resultMap = new HashMap();

        if(obj==null){
            resultMap.put("result","sessionerror");
        }else if(StringUtils.isNullOrEmpty(oldpassword)){
            resultMap.put("result","error");
        }else{
            String userPassword = ((User) obj).getUserPassword();
            if(oldpassword.equals(userPassword)){
                resultMap.put("result","true");
            }else{
                resultMap.put("result","false");
            }
        }

        try {
            resp.setContentType("application/json");
            PrintWriter writer = resp.getWriter();
            writer.write(JSONArray.toJSONString(resultMap));
            writer.flush();
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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    3.测试

    六、用户管理实现

    1.获取用户数量

    1.UserDao

     //查询用户总数
    public int getUserCount(Connection connection,String username,int userRole) throws SQLException;

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    2.UserDaoImpl

        public int getUserCount(Connection connection, String username, int userRole) throws SQLException {
        PreparedStatement pstm = null;
        ResultSet rs = null;
        int count = 0;
        if(connection != null){
            StringBuilder sql = new StringBuilder();
            sql.append("select count(1) as count from smbms_user u,smbms_role r where u.userRole = r.id");
            ArrayList list = new ArrayList();

            if(!StringUtils.isNullOrEmpty(username)){
                sql.append(" and u.userName like ? ");
                list.add("%"+username+"%");
            }

            if(userRole>0){
                sql.append(" and u.userRole = ? ");
                list.add(userRole);
            }

            Object[] params = list.toArray();
            rs = BaseDao.execute(connection,pstm,rs,sql.toString(),params);
            if(rs.next()){
                count = rs.getInt("count");
            }
            BaseDao.closeResource(null,pstm,rs);
        }
        return count;
    }

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    3.UserService
     

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

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    4.UserServiceImpl
     

     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;
    }

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    2.用户列表页导入
     

    1.UserDao
     

     //通过用户输入的条件查询用户列表
    public List getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws  Exception;

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    2.UserDaoImpl
     

     //通过用户输入的条件查询用户列表
    public List getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws Exception {
        List userList = new ArrayList();
        PreparedStatement pstm=null;
        ResultSet rs=null;
        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 list = new ArrayList();
            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;
    }

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    3.UserService
     

     //根据条件查询用户列表
    public List getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize);

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    4.UserServiceImpl
     

    public List getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize) {
        Connection connection = null;
        List 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;
    }

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    3.获取角色操作
     

    1.RoleDao
     

    //获取角色列表
    public List getRoleList(Connection connection) throws SQLException;

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    2.RoleDaoImpl
     

    package com.mario.dao.role;

import com.mario.dao.BaseDao;
import com.mario.entity.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;

public class RoleDaoImpl implements RoleDao{
    //获取角色列表
    public List getRoleList(Connection connection) throws SQLException {
        PreparedStatement pstm = null;
        ResultSet rs = null;
        ArrayList rolesList = new ArrayList();


        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"));
                rolesList.add(_role);
            }
            BaseDao.closeResource(null, pstm, rs);
        }
        return rolesList;
    }

}

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    3.RoleService
     

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

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    4.RoleServiceImpl
     

    package com.mario.service.role;

import com.mario.dao.BaseDao;
import com.mario.dao.role.RoleDao;
import com.mario.dao.role.RoleDaoImpl;
import com.mario.entity.Role;

import java.sql.Connection;
import java.util.List;

public class RoleServiceImpl implements RoleService{

    private RoleDao roleDao;
    public RoleServiceImpl(){
        roleDao = new RoleDaoImpl();
    }

    //获取角色列表
    public List getRoleList() {
        Connection connection=null;
        List roleList=null;
        try {
            connection= BaseDao.getConnection();
            roleList = roleDao.getRoleList(connection);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            BaseDao.closeResource(connection,null,null);
        }
        return roleList;
    }
}

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    4.用户显示的Servlet
     

    •  
      获取用户前端的数据（查询）
       
    •  
      判断请求是否需要执行，看参数的值判断
       
    •  
      为了实现分页，需要计算出当前页面和总页面，页面的大小
       
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      用户列表展示
       
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      返回前端
       
      package com.mario.servlet;
       
      import com.alibaba.fastjson.JSONArray;
       import com.mario.entity.Role;
       import com.mario.entity.User;
       import com.mario.service.role.RoleService;
       import com.mario.service.role.RoleServiceImpl;
       import com.mario.service.user.UserService;
       import com.mario.service.user.UserServiceImpl;
       import com.mario.util.Constants;
       import com.mario.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;
       
      public class UserServlet extends HttpServlet {
       
      @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);
    }else if(method.equals("pwdmodify") && method != null){
        this.pwdModify(req,resp);
    }else if(method.equals("query") && method != null){
        this.query(req,resp);
    }
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
}

public void query(HttpServletRequest req, HttpServletResponse resp){
    //接收前端传来的参数
    String queryUserName = req.getParameter("queryname");
    String temp = req.getParameter("queryUserRole");//从前端传回来的用户角色码不知是否为空或者是有效角色码，所以暂存起来
    String pageIndex = req.getParameter("pageIndex");
    int queryUserRole=0;

    //通过UserServiceImpl得到用户列表,用户数
    UserServiceImpl userService = new UserServiceImpl();
    List userList = null;//用来存储用户列表

    //设置每页显示的页面容量
    int pageSize = 5;
    //设置当前的默认页码
    int currentPageNo=1;

    //前端传来的参数若不符合查询sql语句，即如果用户不进行设置，值为空会影响sql查询，需要给它们进行一些约束
    if(queryUserName==null){//这里为空，说明用户没有输入要查询的用户名，则sql语句传值为""，%%，会查询所有记录
        queryUserName="";
    }
    if(temp!=null && !temp.equals("")){
        //不为空，说明前端有传来的用户所设置的userCode，更新真正的角色码
        queryUserRole=Integer.parseInt(temp);//强制转换，前端传递的参数都是默认字符串，要转成int类型
    }
    if(pageIndex!=null){//说明当前用户有进行设置跳转页面
        currentPageNo=Integer.valueOf(pageIndex);
    }

    //有了用户名和用户角色后可以开始查询了，所以需要显示当前查询到的总记录条数
    int totalCount = userService.getUserCount(queryUserName, queryUserRole);
    //根据总记录条数以及当前每页的页面容量可以算出，一共有几页，以及最后一页的显示条数
    PageSupport pageSupport = new PageSupport();
    pageSupport.setCurrentPageNo(currentPageNo);
    pageSupport.setPageSize(pageSize);
    pageSupport.setTotalCount(totalCount);

    //可显示的总页数
    int totalPageCount=pageSupport.getTotalPageCount();

    //约束首位页，即防止用户输入的页面索引小于1或者大于总页数
    if(currentPageNo<1){
        currentPageNo=1;
    }else if(currentPageNo>totalPageCount){
        currentPageNo=totalPageCount;
    }

    //有了，待查询条件，当前页码，以及每页的页面容量后，就可以给出每页的具体显示情况了
     userList = userService.getUserList(queryUserName, queryUserRole, currentPageNo, pageSize);
    req.setAttribute("userList",userList);

    //通过RoleServiceImpl得到角色表
    RoleService roleService = new RoleServiceImpl();
    List roleList = roleService.getRoleList();//用来存储角色表
    //得到了用户表与角色表以及各种经过处理后的参数，都存进req中
    req.setAttribute("roleList",roleList);
    req.setAttribute("totalCount", totalCount);
    req.setAttribute("currentPageNo", currentPageNo);
    req.setAttribute("totalPageCount", totalPageCount);
    req.setAttribute("queryUserName", queryUserName);
    req.setAttribute("queryUserRole", queryUserRole);
    
    //将所得到的的所有req参数送回给前端
    try {
        req.getRequestDispatcher("userlist.jsp").forward(req,resp);
    } catch (ServletException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

//修改密码
public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String newpassword = req.getParameter("newpassword");

    System.out.println(newpassword);

    boolean flag = false;

    if(obj != null && newpassword != null){
        UserService userService = new UserServiceImpl();
        flag = userService.updatePwd(((User) obj).getId(), newpassword);
        if(flag){
            req.setAttribute("message","修改密码成功");
            req.getSession().removeAttribute(Constants.USER_SESSION);
        }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();
    }
}

//验证旧密码,session中有用户的密码
public void pwdModify(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String oldpassword = req.getParameter("oldpassword");

    Map resultMap = new HashMap();

    if(obj==null){
        resultMap.put("result","sessionerror");
    }else if(StringUtils.isNullOrEmpty(oldpassword)){
        resultMap.put("result","error");
    }else{
        String userPassword = ((User) obj).getUserPassword();
        if(oldpassword.equals(userPassword)){
            resultMap.put("result","true");
        }else{
            resultMap.put("result","false");
        }
    }

    try {
        resp.setContentType("application/json");
        PrintWriter writer = resp.getWriter();
        writer.write(JSONArray.toJSONString(resultMap));
        writer.flush();
        writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

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      }
       
     

    七、订单管理（增删改查）
     

    八、供应商管理（增删改查）
     

    文章上面的代码只有一部分具体看项目里面的代码…
     

    &
     

    &
     

    &
     

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    • 
                
  • 
                    原文地址：https://blog.csdn.net/m0_67401228/article/details/126066942
                
    •