【愚公系列】2023年04月 Java面面刷题系统-001.项目架构和（企业、部门、用户）

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前言

刷题系统是指一种用于学习和练习编程技能的在线平台，其中包含了大量的编程题目和测试用例，用户可以通过完成这些题目来提高自己的编程能力。刷题系统通常会提供一些辅助功能，如智能评测、代码分享、讨论区等，以帮助用户更好地学习和交流。刷题系统也被广泛应用于编程竞赛和招聘面试等场景。常见的刷题系统包括LeetCode、HackerRank、Codeforces等。

本文主要讲解简单的刷题系统项目

一、项目架构

1.项目架构

后台系统和前台系统是指网站或应用程序的两个主要组成部分。

• 后台系统是指网站或应用程序的管理后台，主要用于管理网站或应用程序的各项设置和数据。后台系统通常只对管理员或特定用户开放，具有高度的安全性和权限管理功能。后台系统包括用户管理、内容管理、订单管理、数据分析等功能。
• 前台系统是指网站或应用程序的用户界面，主要用于展示网站或应用程序的各种功能和内容，是用户与网站或应用程序交互的主要界面。前台系统需要具备良好的界面设计和易用性，以吸引用户并提高用户的使用体验。前台系统包括主页、产品展示、购物车、搜索、支付等功能。

因此，后台系统和前台系统是网站或应用程序不可或缺的两个组成部分，它们共同构成了一个完整的网站或应用程序。

2.技术架构

• AdminLTE：一个前端框架，提供了很多友好的主题样式，动态功能效果，可直接使用，非常方便
• POI：数据报表工具，可用于报表导出
• Element-UI：主要前台页面设计的UI框架
• VUE：标准的前端三大件之一的VUE框架，负责数据动态绑定和业务处理

3.项目功能分析

二、企业、部门、用户模块

1. 环境搭建

1.1 工程结构搭建

1、创建项目：mm

<groupId>com.itheimagroupId>
<artifactId>mmartifactId>
<version>1.0-SNAPSHOTversion>
<packaging>warpackaging>

2、在pom.xml文件中添加相关坐标：

<properties>
    <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
    <maven.compiler.source>1.8maven.compiler.source>
    <maven.compiler.target>1.8maven.compiler.target>
properties>

<dependencies>
    
    <dependency>
        <groupId>org.mybatisgroupId>
        <artifactId>mybatisartifactId>
        <version>3.5.3version>
    dependency>
    
    <dependency>
        <groupId>com.github.pagehelpergroupId>
        <artifactId>pagehelperartifactId>
        <version>5.1.2version>
    dependency>
    
    <dependency>
        <groupId>mysqlgroupId>
        <artifactId>mysql-connector-javaartifactId>
        <version>5.1.46version>
    dependency>
    
    <dependency>
        <groupId>com.alibabagroupId>
        <artifactId>druidartifactId>
        <version>1.1.21version>
    dependency>
    
    <dependency>
        <groupId>junitgroupId>
        <artifactId>junitartifactId>
        <version>4.12version>
        <scope>testscope>
    dependency>
    
    <dependency>
        <groupId>javax.servletgroupId>
        <artifactId>javax.servlet-apiartifactId>
        <version>3.1.0version>
        <scope>providedscope>
    dependency>
    
    <dependency>
        <groupId>javax.servlet.jspgroupId>
        <artifactId>javax.servlet.jsp-apiartifactId>
        <version>2.3.3version>
        <scope>providedscope>
    dependency>
    
    <dependency>
        <groupId>commons-beanutilsgroupId>
        <artifactId>commons-beanutilsartifactId>
        <version>1.9.4version>
    dependency>
    
    <dependency>
        <groupId>org.apache.commonsgroupId>
        <artifactId>commons-lang3artifactId>
        <version>3.9version>
    dependency>
    
    <dependency>
        <groupId>jstlgroupId>
        <artifactId>jstlartifactId>
        <version>1.2version>
    dependency>
    
    <dependency>
        <groupId>com.fasterxml.jackson.coregroupId>
        <artifactId>jackson-annotationsartifactId>
        <version>2.9.0version>
    dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.coregroupId>
        <artifactId>jackson-coreartifactId>
        <version>2.9.0version>
    dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.coregroupId>
        <artifactId>jackson-databindartifactId>
        <version>2.9.0version>
    dependency>
    
    <dependency>
        <groupId>commons-fileuploadgroupId>
        <artifactId>commons-fileuploadartifactId>
        <version>1.3.1version>
    dependency>
    
    <dependency>
        <groupId>org.apache.poigroupId>
        <artifactId>poiartifactId>
        <version>4.0.1version>
    dependency>
    <dependency>
        <groupId>org.apache.poigroupId>
        <artifactId>poi-ooxmlartifactId>
        <version>4.0.1version>
    dependency>
    <dependency>
        <groupId>org.apache.poigroupId>
        <artifactId>poi-ooxml-schemasartifactId>
        <version>4.0.1version>
    dependency>
dependencies>

<build>
    <plugins>
        
        <plugin>
            <groupId>org.apache.tomcat.mavengroupId>
            <artifactId>tomcat7-maven-pluginartifactId>
            <version>2.1version>
            <configuration>
                <port>80port>
                <path>/path>
            configuration>
        plugin>
    plugins>
build>

3、创建相关目录结构，包结构，如下

删除：web.xml

4、数据库表设计

1.2 页面结构设计

2. 企业模块

2.1 数据层开发

1、创建实体：Company

public class Company {

    private String id;
    private String name;
    private Date expirationDate;
    private String address;
    private String licenseId;
    private String representative;
    private String phone;
    private String companySize;
    private String industry;
    private String remarks;
    private Integer state;
    private String city;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Date getExpirationDate() {
        return expirationDate;
    }

    public void setExpirationDate(Date expirationDate) {
        this.expirationDate = expirationDate;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getLicenseId() {
        return licenseId;
    }

    public void setLicenseId(String licenseId) {
        this.licenseId = licenseId;
    }

    public String getRepresentative() {
        return representative;
    }

    public void setRepresentative(String representative) {
        this.representative = representative;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getCompanySize() {
        return companySize;
    }

    public void setCompanySize(String companySize) {
        this.companySize = companySize;
    }

    public String getIndustry() {
        return industry;
    }

    public void setIndustry(String industry) {
        this.industry = industry;
    }

    public String getRemarks() {
        return remarks;
    }

    public void setRemarks(String remarks) {
        this.remarks = remarks;
    }

    public Integer getState() {
        return state;
    }

    public void setState(Integer state) {
        this.state = state;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }
}

2、创建dao：CompanyDao

public interface CompanyDao {

    int save(Company company);

    int delete(Company company);

    int update(Company company);

    Company findById(String id);

    List<Company> findAll();

}

3、核心配置文件

2.2 业务层开发

1、创建业务层接口：CompanyService

public interface CompanyService {

    /**
     * 添加
     * @param company
     * @return
     */
    void save(Company company);

    /**
     * 删除
     * @param company
     * @return
     */
    void delete(Company company);

    /**
     * 修改
     * @param company
     * @return
     */
    void update(Company company);

    /**
     * 查询单个
     * @param id 查询的条件（id）
     * @return 查询的结果，单个对象
     */
    Company findById(String id);

    /**
     * 查询全部的数据
     * @return 全部数据的列表对象
     */
    List<Company> findAll();

    /**
     * 分页查询数据
     * @param page 页码
     * @param size 每页显示的数据总量
     * @return
     */
    PageInfo findAll(int page,int size);

}

2、CompanyServiceImpl

public class CompanyServiceImpl implements CompanyService {
    @Override
    public void save(Company company) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            CompanyDao companyDao = MapperFactory.getMapper(sqlSession,CompanyDao.class);
            //id使用UUID的生成策略来获取
            String id = UUID.randomUUID().toString();
            company.setId(id);
            //3.调用Dao层操作
            companyDao.save(company);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public void delete(Company company) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            CompanyDao companyDao = MapperFactory.getMapper(sqlSession,CompanyDao.class);
            //3.调用Dao层操作
            companyDao.delete(company);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public void update(Company company) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            CompanyDao companyDao = MapperFactory.getMapper(sqlSession,CompanyDao.class);
            //3.调用Dao层操作
            companyDao.update(company);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public Company findById(String id) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            CompanyDao companyDao = MapperFactory.getMapper(sqlSession,CompanyDao.class);
            //3.调用Dao层操作
            return companyDao.findById(id);
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public List<Company> findAll() {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            CompanyDao companyDao = MapperFactory.getMapper(sqlSession,CompanyDao.class);
            //3.调用Dao层操作
            return companyDao.findAll();
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public PageInfo findAll(int page, int size) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            CompanyDao companyDao = MapperFactory.getMapper(sqlSession,CompanyDao.class);
            //3.调用Dao层操作
            PageHelper.startPage(page,size);
            List<Company> all = companyDao.findAll();
            PageInfo pageInfo = new PageInfo(all);
            return pageInfo;
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

3、创建测试类：CompanyServiceTest

public class CompanyServiceTest {
    private static CompanyService companyService = null;
    @BeforeClass
    public static void init(){
        companyService = new CompanyServiceImpl();
    }

    @Test
    public void testSave(){
        Company company = new Company();
        company.setName("测试数据");
        companyService.save(company);
    }

    @Test
    public void testFindAll(){
        PageInfo all = companyService.findAll(1, 100);
        System.out.println(all);
    }

    @AfterClass
    public static void destory(){
        companyService = null;
    }


}

2.3 表现层列表功能

1、BaseServlet基类：主要负责业务层实例初始化

package com.itheima.web.controller;

import com.itheima.service.store.*;
import com.itheima.service.store.impl.*;
import com.itheima.service.system.DeptService;
import com.itheima.service.system.ModuleService;
import com.itheima.service.system.RoleService;
import com.itheima.service.system.UserService;
import com.itheima.service.system.impl.DeptServiceImpl;
import com.itheima.service.system.impl.ModuleServiceImpl;
import com.itheima.service.system.impl.RoleServiceImpl;
import com.itheima.service.system.impl.UserServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;

public class BaseServlet extends HttpServlet {
    protected CompanyService companyService;
    protected DeptService deptService;
    protected UserService userService;
    protected CourseService courseService;
    protected CatalogService catalogService;
    protected QuestionService questionService;
    protected QuestionItemService questionItemService;
    protected RoleService roleService;
    protected ModuleService moduleService;

    @Override
    public void init() throws ServletException {
        companyService = new CompanyServiceImpl();
        deptService = new DeptServiceImpl();
        userService = new UserServiceImpl();
        courseService = new CourseServiceImpl();
        catalogService = new CatalogServiceImpl();
        questionService = new QuestionServiceImpl();
        questionItemService = new QuestionItemServiceImpl();
        roleService = new RoleServiceImpl();
        moduleService = new ModuleServiceImpl();
    }
}

2、CompanyServlet控制器类：主要负责提供接口的各种服务

package com.itheima.web.controller.store;

import com.github.pagehelper.PageInfo;
import com.itheima.domain.store.Company;
import com.itheima.utils.BeanUtil;
import com.itheima.web.controller.BaseServlet;
import org.apache.commons.lang3.StringUtils;

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

// uri:/store/company?operation=list
@WebServlet("/store/company")
public class CompanyServlet extends BaseServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String operation = request.getParameter("operation");
        if("list".equals(operation)){
            this.list(request,response);
        }else if("toAdd".equals(operation)){
            this.toAdd(request,response);
        }else if("save".equals(operation)){
            this.save(request, response);
        }else if("toEdit".equals(operation)){
            this.toEdit(request,response);
        }else if("edit".equals(operation)){
            this.edit(request,response);
        }else if("delete".equals(operation)){
            this.delete(request,response);
        }
    }

    private void list(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //进入列表页
        //获取数据
        int page = 1;
        int size = 5;
        if(StringUtils.isNotBlank(request.getParameter("page"))){
            page = Integer.parseInt(request.getParameter("page"));
        }
        if(StringUtils.isNotBlank(request.getParameter("size"))){
            size = Integer.parseInt(request.getParameter("size"));
        }
        PageInfo all = companyService.findAll(page, size);
        //将数据保存到指定的位置
        request.setAttribute("page",all);
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/store/company/list.jsp").forward(request,response);
    }

    private void toAdd(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/store/company/add.jsp").forward(request,response);
    }

    private void save(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //将数据获取到，封装成一个对象
        Company company = BeanUtil.fillBean(request,Company.class,"yyyy-MM-dd");
        //调用业务层接口save
        companyService.save(company);
        //跳转回到页面list
        response.sendRedirect(request.getContextPath()+"/store/company?operation=list");
    }

    private void toEdit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //查询要修改的数据findById
        String id = request.getParameter("id");
        Company company = companyService.findById(id);
        //将数据加载到指定区域，供页面获取
        request.setAttribute("company",company);
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/store/company/update.jsp").forward(request,response);
    }

    private void edit(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //将数据获取到，封装成一个对象
        Company company = BeanUtil.fillBean(request,Company.class,"yyyy-MM-dd");
        //调用业务层接口save
        companyService.update(company);
        //跳转回到页面list
        response.sendRedirect(request.getContextPath()+"/store/company?operation=list");
    }

    private void delete(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //将数据获取到，封装成一个对象
        Company company = BeanUtil.fillBean(request,Company.class);
        //调用业务层接口save
        companyService.delete(company);
        //跳转回到页面list
        response.sendRedirect(request.getContextPath()+"/store/company?operation=list");
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }
}

3、实际页面的增删改查

3. 部门模块

3.1 数据层开发

1、创建实体：Dept

public class Dept {
    private String id;
    private String deptName;
    private String parentId;
    private Integer state;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getDeptName() {
        return deptName;
    }

    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }

    public String getParentId() {
        return parentId;
    }

    public void setParentId(String parentId) {
        this.parentId = parentId;
    }

    public Integer getState() {
        return state;
    }

    public void setState(Integer state) {
        this.state = state;
    }
}

2、创建dao接口：DeptDao

public interface DeptDao {
    int save(Dept dept);

    int delete(Dept dept);

    int update(Dept dept);

    Dept findById(String id);

    List<Dept> findAll();

}

3、核心配置文件

3.2 业务层开发

1、创建业务层接口：DeptService

public interface DeptService {
    /**
     * 添加
     * @param dept
     * @return
     */
    void save(Dept dept);

    /**
     * 删除
     * @param dept
     * @return
     */
    void delete(Dept dept);

    /**
     * 修改
     * @param dept
     * @return
     */
    void update(Dept dept);

    /**
     * 查询单个
     * @param id 查询的条件（id）
     * @return 查询的结果，单个对象
     */
    Dept findById(String id);

    /**
     * 查询全部的数据
     * @return 全部数据的列表对象
     */
    List<Dept> findAll();

    /**
     * 分页查询数据
     * @param page 页码
     * @param size 每页显示的数据总量
     * @return
     */
    PageInfo findAll(int page, int size);
}

2、创建业务层实现类：DeptServiceImpl

public class DeptServiceImpl implements DeptService {
    @Override
    public void save(Dept dept) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            DeptDao deptDao = MapperFactory.getMapper(sqlSession,DeptDao.class);
            //id使用UUID的生成策略来获取
            String id = UUID.randomUUID().toString();
            dept.setId(id);
            //3.调用Dao层操作
            deptDao.save(dept);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public void delete(Dept dept) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            DeptDao deptDao = MapperFactory.getMapper(sqlSession,DeptDao.class);
            //3.调用Dao层操作
            deptDao.delete(dept);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public void update(Dept dept) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            DeptDao deptDao = MapperFactory.getMapper(sqlSession,DeptDao.class);
            //3.调用Dao层操作
            deptDao.update(dept);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public Dept findById(String id) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            DeptDao deptDao = MapperFactory.getMapper(sqlSession,DeptDao.class);
            //3.调用Dao层操作
            return deptDao.findById(id);
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public List<Dept> findAll() {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            DeptDao deptDao = MapperFactory.getMapper(sqlSession,DeptDao.class);
            //3.调用Dao层操作
            return deptDao.findAll();
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public PageInfo findAll(int page, int size) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            DeptDao deptDao = MapperFactory.getMapper(sqlSession,DeptDao.class);
            //3.调用Dao层操作
            PageHelper.startPage(page,size);
            List<Dept> all = deptDao.findAll();
            PageInfo pageInfo = new PageInfo(all);
            return pageInfo;
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

3.3 表现层列表功能

1、创建Servlet：DeptServlet

// uri:/system/dept?operation=list
@WebServlet("/system/dept")
public class DeptServlet extends BaseServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String operation = request.getParameter("operation");
        if("list".equals(operation)){
            this.list(request,response);
        }else if("toAdd".equals(operation)){
            this.toAdd(request,response);
        }else if("save".equals(operation)){
            this.save(request, response);
        }else if("toEdit".equals(operation)){
            this.toEdit(request,response);
        }else if("edit".equals(operation)){
            this.edit(request,response);
        }else if("delete".equals(operation)){
            this.delete(request,response);
        }
    }

    private void list(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //进入列表页
        //获取数据
        int page = 1;
        int size = 5;
        if(StringUtils.isNotBlank(request.getParameter("page"))){
            page = Integer.parseInt(request.getParameter("page"));
        }
        if(StringUtils.isNotBlank(request.getParameter("size"))){
            size = Integer.parseInt(request.getParameter("size"));
        }
        PageInfo all = deptService.findAll(page, size);
        //将数据保存到指定的位置
        request.setAttribute("page",all);
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/system/dept/list.jsp").forward(request,response);
    }

    private void toAdd(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/system/dept/add.jsp").forward(request,response);
    }

    private void save(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //将数据获取到，封装成一个对象
        Dept dept = BeanUtil.fillBean(request,Dept.class,"yyyy-MM-dd");
        //调用业务层接口save
//        DeptService deptService = new DeptServiceImpl();
        deptService.save(dept);
        //跳转回到页面list
        //list(request,response);
        response.sendRedirect(request.getContextPath()+"/system/dept?operation=list");
    }

    private void toEdit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //查询要修改的数据findById
        String id = request.getParameter("id");
//        DeptService deptService = new DeptServiceImpl();
        Dept dept = deptService.findById(id);
        //将数据加载到指定区域，供页面获取
        request.setAttribute("dept",dept);
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/system/dept/update.jsp").forward(request,response);
    }

    private void edit(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //将数据获取到，封装成一个对象
        Dept dept = BeanUtil.fillBean(request,Dept.class,"yyyy-MM-dd");
        //调用业务层接口save
//        DeptService deptService = new DeptServiceImpl();
        deptService.update(dept);
        //跳转回到页面list
        //list(request,response);
        response.sendRedirect(request.getContextPath()+"/system/dept?operation=list");
    }

    private void delete(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //将数据获取到，封装成一个对象
        Dept dept = BeanUtil.fillBean(request,Dept.class);
        //调用业务层接口save
//        DeptService deptService = new DeptServiceImpl();
        deptService.delete(dept);
        //跳转回到页面list
        //list(request,response);
        response.sendRedirect(request.getContextPath()+"/system/dept?operation=list");
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }
}

2、在BaseServlet中添加新的代码，如下

public class BaseServlet extends HttpServlet {
    protected CompanyService companyService;
    protected DeptService deptService;

    @Override
    public void init() throws ServletException {
        companyService = new CompanyServiceImpl();
        deptService = new DeptServiceImpl();
    }
}

3、实际页面的增删改查

4. 部门模块

4.1 数据层开发

1、创建实体：User

public class User {
    private String id;
    private String email;       //邮箱
    private String userName;    //姓名
    private String password;    //密码
    private Long state;         //状态
    private String gender;      //性别
    private String telephone;   //电话
    private Date birthday;      //出生年月
    private Date joinDate;      //入职时间
    private String deptId;      //部门id

    private Dept dept;

    public Dept getDept() {
        return dept;
    }

    @Override
    public String toString() {
        return "User{" +
                "id='" + id + '\'' +
                ", email='" + email + '\'' +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                ", state=" + state +
                ", gender='" + gender + '\'' +
                ", telephone='" + telephone + '\'' +
                ", birthday=" + birthday +
                ", joinDate=" + joinDate +
                ", deptId='" + deptId + '\'' +
                ", dept=" + dept +
                '}';
    }

	//---------get/set方法略
}

2、创建dao接口：UserDao

public interface UserDao {
    int save(User user);

    int delete(User user);

    int update(User user);

    User findById(String id);

    List<User> findAll();
}

3、核心配置类

4.2 业务层开发

1、创建业务层接口：UserService

public interface UserService {
    /**
     * 添加
     * @param user
     * @return
     */
    void save(User user);

    /**
     * 删除
     * @param user
     * @return
     */
    void delete(User user);

    /**
     * 修改
     * @param user
     * @return
     */
    void update(User user);

    /**
     * 查询单个
     * @param id 查询的条件（id）
     * @return 查询的结果，单个对象
     */
    User findById(String id);

    /**
     * 查询全部的数据
     * @return 全部数据的列表对象
     */
    List<User> findAll();

    /**
     * 分页查询数据
     * @param page 页码
     * @param size 每页显示的数据总量
     * @return
     */
    PageInfo findAll(int page, int size);
}

2、创建业务层实现类：UserServiceImpl

public class UserServiceImpl implements UserService {
    @Override
    public void save(User user) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            UserDao userDao = MapperFactory.getMapper(sqlSession,UserDao.class);
            //id使用UUID的生成策略来获取
            String id = UUID.randomUUID().toString();
            user.setId(id);
            //3.调用Dao层操作
            userDao.save(user);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public void delete(User user) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            UserDao userDao = MapperFactory.getMapper(sqlSession,UserDao.class);
            //3.调用Dao层操作
            userDao.delete(user);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public void update(User user) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            UserDao userDao = MapperFactory.getMapper(sqlSession,UserDao.class);
            //3.调用Dao层操作
            userDao.update(user);
            //4.提交事务
            TransactionUtil.commit(sqlSession);
        }catch (Exception e){
            TransactionUtil.rollback(sqlSession);
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public User findById(String id) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            UserDao userDao = MapperFactory.getMapper(sqlSession,UserDao.class);
            //3.调用Dao层操作
            return userDao.findById(id);
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public List<User> findAll() {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            UserDao userDao = MapperFactory.getMapper(sqlSession,UserDao.class);
            //3.调用Dao层操作
            return userDao.findAll();
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    @Override
    public PageInfo findAll(int page, int size) {
        SqlSession sqlSession = null;
        try{
            //1.获取SqlSession
            sqlSession = MapperFactory.getSqlSession();
            //2.获取Dao
            UserDao userDao = MapperFactory.getMapper(sqlSession,UserDao.class);
            //3.调用Dao层操作
            PageHelper.startPage(page,size);
            List<User> all = userDao.findAll();
            PageInfo pageInfo = new PageInfo(all);
            return pageInfo;
        }catch (Exception e){
            throw new RuntimeException(e);
            //记录日志
        }finally {
            try {
                TransactionUtil.close(sqlSession);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

4.3 表现层列表功能

1、创建servlet：com.itheima.web.controller.system.UserServlet

// uri:/system/user?operation=list
@WebServlet("/system/user")
public class UserServlet extends BaseServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String operation = request.getParameter("operation");
        if("list".equals(operation)){
            this.list(request,response);
        }else if("toAdd".equals(operation)){
            this.toAdd(request,response);
        }else if("save".equals(operation)){
            this.save(request, response);
        }else if("toEdit".equals(operation)){
            this.toEdit(request,response);
        }else if("edit".equals(operation)){
            this.edit(request,response);
        }else if("delete".equals(operation)){
            this.delete(request,response);
        }
    }

    private void list(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //进入列表页
        //获取数据
//        UserService userService = new UserServiceImpl();
        int page = 1;
        int size = 5;
        if(StringUtils.isNotBlank(request.getParameter("page"))){
            page = Integer.parseInt(request.getParameter("page"));
        }
        if(StringUtils.isNotBlank(request.getParameter("size"))){
            size = Integer.parseInt(request.getParameter("size"));
        }
        PageInfo all = userService.findAll(page, size);
        //将数据保存到指定的位置
        request.setAttribute("page",all);
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/system/user/list.jsp").forward(request,response);
    }

    private void toAdd(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/system/user/add.jsp").forward(request,response);
    }

    private void save(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        //将数据获取到，封装成一个对象
        User user = BeanUtil.fillBean(request,User.class,"yyyy-MM-dd");
        //调用业务层接口save
        userService.save(user);
        //跳转回到页面list
        response.sendRedirect(request.getContextPath()+"/system/user?operation=list");
    }

    private void toEdit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //查询要修改的数据findById
        String id = request.getParameter("id");
        User user = userService.findById(id);
        //将数据加载到指定区域，供页面获取
        request.setAttribute("user",user);
        //查询部门信息
        List<Dept> all = deptService.findAll();
        //放入指定位置
        request.setAttribute("deptList",all);
        //跳转页面
        request.getRequestDispatcher("/WEB-INF/pages/system/user/update.jsp").forward(request,response);
    }

    private void edit(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //将数据获取到，封装成一个对象
        User user = BeanUtil.fillBean(request,User.class,"yyyy-MM-dd");
        //调用业务层接口save
        userService.update(user);
        //跳转回到页面list
        response.sendRedirect(request.getContextPath()+"/system/user?operation=list");
    }

    private void delete(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //将数据获取到，封装成一个对象
        User user = BeanUtil.fillBean(request,User.class);
        //调用业务层接口save
        userService.delete(user);
        //跳转回到页面list
        response.sendRedirect(request.getContextPath()+"/system/user?operation=list");
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }
}

2、修改BaseServlet

public class BaseServlet extends HttpServlet {
    protected CompanyService companyService;
    protected DeptService deptService;
    protected UserService userService;

    @Override
    public void init() throws ServletException {
        companyService = new CompanyServiceImpl();
        deptService = new DeptServiceImpl();
        userService = new UserServiceImpl();
    }
}

3、具体实现页面