GIF动态图演示

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
  

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

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

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;
    }
}

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

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

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;
}

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;
    }
}

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);
}

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;
    }
}

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);
    }
}

8.注册servlet

xml代码

<servlet>
        <servlet-name>LoginServlet</servlet-name>
        <servlet-class>com.syj.servlet.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

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);
    }
}

xml 代码

<!--注销-->
    <servlet>
        <servlet-name>LogoutServlet</servlet-name>
        <servlet-class>com.syj.servlet.LogoutServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LogoutServlet</servlet-name>
        <url-pattern>/jsp/logout.do</url-pattern>
    </servlet-mapping>

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() {
    }
}

xml 代码

   <!--    用户登录过滤器-->
    <filter>
        <filter-name>SysFilter</filter-name>
        <filter-class>com.syj.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，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

<li.><a.href=“${pageContext.request.contextPath }/jsp/pwdmodify.jsp”>密码修改</li.>

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;

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;
    }

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 false;
    }

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();
        }
    }
}

8. 测试

优化密码修改使用Ajax

1.阿里巴巴的fastjson

pom.xml

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.61</version>
    </dependency>

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<String, String> resultMap = new HashMap<String, String>();
        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();
        }
    }
}

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;

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<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);
            }
            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;
    }

3.UserService

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

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;
    }

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<User> getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws  Exception;

2.UserDaoImpl

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

3.UserService

 //根据条件查询用户列表
    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

1.RoleDao

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

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<Role> getRoleList(Connection connection) throws SQLException {
        PreparedStatement pstm = null;
        ResultSet rs = null;
        ArrayList<Role> rolesList = 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"));
                rolesList.add(_role);
            }
            BaseDao.closeResource(null, pstm, rs);
        }
        return rolesList;
    }
}

3.RoleService

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

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<Role> getRoleList() {
        Connection connection=null;
        List<Role> roleList=null;
        try {
            connection= BaseDao.getConnection();
            roleList = roleDao.getRoleList(connection);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            BaseDao.closeResource(connection,null,null);
        }
        return roleList;
    }
}

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

• 用户列表展示

• 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<User> 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<Role> 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<String, String> resultMap = new HashMap<String, String>();
      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();
      }
  }
  

  }

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…

&

&

&

先自我介绍一下，小编13年上师交大毕业，曾经在小公司待过，去过华为OPPO等大厂，18年进入阿里，直到现在。深知大多数初中级java工程师，想要升技能，往往是需要自己摸索成长或是报班学习，但对于培训机构动则近万元的学费，着实压力不小。自己不成体系的自学效率很低又漫长，而且容易碰到天花板技术停止不前。因此我收集了一份《java开发全套学习资料》送给大家，初衷也很简单，就是希望帮助到想自学又不知道该从何学起的朋友，同时减轻大家的负担。添加下方名片，即可获取全套学习资料哦