基于SpringBoot+Mybatis-Plus的快速入门案例

图书管理系统

基于SpringBoot+Mybatis-Plus的快速入门案例

图书管理系统 源码已上传Gitee 源码地址

参考视频 : 黑马程序员SpringBoot

1. 技术栈和环境配置

• SpringBoot 2.6.7
• Mybatis-Plus 3.4.3
• Lombok 1.18
• mysql 5.6
• JDK 8

2.案例效果演示

• 2.1添加书籍
• 2.2 删除书籍
• 2.3 修改书籍
• 2.4 按条件查询书籍
• 2.5分页

3.案例分析

3.1实体类

使用Lombok快速制作实体类

@Data//标注sql数据表名称@TableName("t_book")publicclassBooks{privateInteger id;privateString type;privateString name;privateString description;}

3.2数据层

整合MybatisPlus

application.yml文件

#端口号server:port:80#数据源spring:datasource:druid:driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/db4?serverTimezone=UTC
      username: root
      password:#mybatis-plus 使用数据库自增算法mybatis-plus:global-config:db-config:id-type: auto
  configuration:log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

#开启MP日志并设置输出方式为标准输出(输出控制台) 用于测试

配置MP的分页拦截器

@ConfigurationpublicclassMPConfig{@BeanpublicMybatisPlusInterceptormybatisPlusInterceptor(){MybatisPlusInterceptor interceptor =newMybatisPlusInterceptor();
        interceptor.addInnerInterceptor(newPaginationInnerInterceptor());return interceptor;}}

MySQL数据表——t_book

CREATETABLE t_book(
id INTNOTNULLAUTO_INCREMENT,TYPEVARCHAR(20),
NAME VARCHAR(20),
description VARCHAR(20),PRIMARYKEY(id))ENGINE=INNODBDEFAULTCHARSET=utf8;

3.3业务层/服务层

基于MyBatisPlus进行增量开发

IBookService接口类

注：此接口继承MybatisPlus提供的IService接口，默认实现了许多业务操作

publicinterfaceIBookServiceextendsIService<Books>{booleansaveBook(Books books);booleanmodify(Books books);booleandelete(Integer id);IPage<Books>getPage(int currentPage,int pageSize);IPage<Books>getPage(int currentPage,int pageSize,Books books);}

BookServiceImpl实现类

注：此类继承ServiceImpl<BookDao,Books>类，参数为接口和实体类，代表映射关系

@ServicepublicclassBookServiceImplextendsServiceImpl<BookDao,Books>implementsIBookService{@AutowiredprivateBookDao bookDao;@OverridepublicbooleansaveBook(Books books){return bookDao.insert(books)>0;}@Overridepublicbooleanmodify(Books books){return bookDao.updateById(books)>0;}@Overridepublicbooleandelete(Integer id){return  bookDao.deleteById(id)>0;}@OverridepublicIPage<Books>getPage(int currentPage,int pageSize){IPage page =newPage(currentPage,pageSize);

       bookDao.selectPage(page,null);return page;}@OverridepublicIPage<Books>getPage(int currentPage,int pageSize,Books books){LambdaQueryWrapper<Books> lqw =newLambdaQueryWrapper<>();
        lqw.like(Strings.isNotEmpty(books.getType()),Books::getType,books.getType());
        lqw.like(Strings.isNotEmpty(books.getName()),Books::getName,books.getName());
        lqw.like(Strings.isNotEmpty(books.getDescription()),Books::getDescription,books.getDescription());IPage page =newPage(currentPage,pageSize);

        bookDao.selectPage(page,lqw);return page;}}

3.4表现层/控制层

基于Restful风格

BookController类

@RestController@RequestMapping("/books")publicclassBookController{@AutowiredprivateIBookService bookService;@GetMappingpublicResultMessagegetAll(){returnnewResultMessage(true,bookService.list());}@PostMappingpublicResultMessagesave(@RequestBodyBooks books){returnnewResultMessage(bookService.saveBook(books));}@DeleteMapping("{id}")publicResultMessagedelete(@PathVariableInteger id){returnnewResultMessage(bookService.delete(id));}@PutMappingpublicResultMessageupdate(@RequestBodyBooks books){returnnewResultMessage(bookService.modify(books));}@GetMapping("{id}")publicResultMessagegetById(@PathVariableInteger id){//true表示查询到数据了 可能为空returnnewResultMessage(true,bookService.getById(id));}/**
     * 分页  条件查询
     * @param currentPage
     * @param pageSize
     * @param books
     * @return
     */@GetMapping("{currentPage}/{pageSize}")publicResultMessagegetPage(@PathVariableint currentPage,@PathVariableint pageSize,Books books){IPage<Books> page = bookService.getPage(currentPage, pageSize,books);//解决删除某页唯一一条数据时，出现空页面的问题if(currentPage > page.getPages()){
              page = bookService.getPage((int) page.getPages(),pageSize,books);}returnnewResultMessage(true, page);}}

表现层消息一致性处理，前后端数据协议

ResultMessage类，消息统一处理

@DatapublicclassResultMessage{privateBoolean flag;privateObject data;privateString message;publicResultMessage(){}publicResultMessage(Boolean flag){this.flag = flag;}publicResultMessage(Boolean flag,Object data){this.flag = flag;this.data = data;}publicResultMessage(String message){this.flag = flag;this.message = message;}publicResultMessage(Boolean flag,String message){this.flag = flag;this.message = message;}}

异常处理

@RestControllerAdvicepublicclassExceptionAdvice{//拦截异常@ExceptionHandlerpublicResultMessagedoException(Exception e){
        e.printStackTrace();returnnewResultMessage("服务器故障,稍后再试");}}

3.5页面开发

基于VUE+ElementUI

页面数据处理、页面消息处理

books.html （部分代码）

<script>var vue =newVue({el:'#app',data:{dataList:[],//当前页要展示的列表数据dialogFormVisible:false,//添加表单是否可见dialogFormVisible4Edit:false,//编辑表单是否可见formData:{},//表单数据rules:{//校验规则type:[{required:true,message:'图书类别为必填项',trigger:'blur'}],name:[{required:true,message:'图书名称为必填项',trigger:'blur'}]},pagination:{//分页相关模型数据currentPage:1,//当前页码pageSize:10,//每页显示的记录数total:0,//总记录数type:"",name:"",description:""}},//钩子函数，VUE对象初始化完成后自动执行created(){this.getAll();}})</script>