SpringBoot MyBatis怎么快速入门

魁首哥

作者

SpringBoot MyBatis怎么快速入门

这篇文章主要介绍“SpringBoot MyBatis怎么快速入门”的相关知识，小编通过实际案例向大家展示操作过程，操作方法简单快捷，实用性强，希望这篇“SpringBoot MyBatis怎么快速入门”文章能帮助大家解决问题。

一、MyBatis简介

MyBatis 是一款优秀的持久层框架，它支持自定义 SQL、存储过程以及高级映射。MyBatis 免除了几乎所有的 JDBC 代码以及设置参数和获取结果集的工作。MyBatis 可以通过简单的 XML 或注解来配置和映射原始类型、接口和 Java POJO（Plain Old Java Objects，普通老式 Java 对象）为数据库中的记录。

二、MyBatis使用步骤

1、MyBatis工程总体目录结构

2、创建简单的SpringBoot工程

3、添加MyBatis依赖

<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.32</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.4.6</version></dependency>

4、在数据库创建USER表

CREATETABLE`user`(`id`int(11)NOTNULLAUTO_INCREMENT,`username`varchar(20)NOTNULLDEFAULT""COMMENT"用户名",`password`varchar(50)NOTNULLDEFAULT""COMMENT"密码",PRIMARYKEY(`id`)USINGBTREE)ENGINE=InnoDBDEFAULTCHARSET=utf8mb4ROW_FORMAT=DYNAMIC;

5、在application.properties配置数据库连接信息

#数据库相关配置spring.datasource.driver-class-name=com.mysql.jdbc.Driverspring.datasource.url=jdbc:mysql://127.0.0.1:3306/test?useSSL=false&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=Asia/Shanghai&useAffectedRows=truespring.datasource.username=rootspring.datasource.password=QQ796413#mybaits配置#mapper加载路径mybatis.mapper-locations=classpath:mapper/*.xml#实体包位置mybatis.type-aliases-package=com.example.mybatisdemo.entity#myatbis配置文件mybatis.config-location=classpath:mybatis-config.xml

6、创建USER表对应的实体类

packagecom.example.mybatisdemo.entity;publicclassUser{privateintid;privateStringusername;privateStringpassword;publicintgetId(){returnid;}publicvoidsetId(intid){this.id=id;}publicStringgetUsername(){returnusername;}publicvoidsetUsername(Stringusername){this.username=username;}publicStringgetPassword(){returnpassword;}publicvoidsetPassword(Stringpassword){this.password=password;}@OverridepublicStringtoString(){return"User{"+"id="+id+",username=""+username+"""+",password=""+password+"""+"}";}

7、在mapper/UserMapper创建UserMapper.java

packagecom.example.mybatisdemo.mapper;importcom.example.mybatisdemo.entity.User;importorg.apache.ibatis.annotations.Mapper;@MapperpublicinterfaceUserMapper{UserfindUserById(Integerid);}

8、在service/UserService新建UserService.java

packagecom.example.mybatisdemo.service;importcom.example.mybatisdemo.entity.User;publicinterfaceUserService{UserfindUserById(Integerid);}

9、在service/impl/UserServiceImpl 创建UserServiceImpl.java

packagecom.example.mybatisdemo.service.impl;importcom.example.mybatisdemo.entity.User;importcom.example.mybatisdemo.mapper.UserMapper;importcom.example.mybatisdemo.service.UserService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Service;@ServicepublicclassUserServiceImplimplementsUserService{@AutowiredprivateUserMapperuserMapper;@OverridepublicUserfindUserById(Integerid){returnuserMapper.findUserById(id);}}

10、在resources下新建mybatis-conf.xml

<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEconfigurationPUBLIC"-//mybatis.org//DTDConfig3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><settings><settingname="logImpl"value="STDOUT_LOGGING"/><settingname="mapUnderscoreToCamelCase"value="true"/><settingname="lazyLoadingEnabled"value="true"/><settingname="returnInstanceForEmptyRow"value="true"/><settingname="callSettersOnNulls"value="true"/></settings></configuration>

11、在resources下mapper文件下创建UserMapper.xml

<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEmapperPUBLIC"-//mybatis.org//DTDMapper3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="com.example.mybatisdemo.mapper.UserMapper"><resultMapid="BaseResultMap"type="com.example.mybatisdemo.entity.User"><resultcolumn="id"property="id"/><resultcolumn="username"property="username"/><resultcolumn="password"property="password"/></resultMap><selectid="findUserById"resultMap="BaseResultMap">selectid,username,passwordfromuserwhereid=#{id,jdbcType=INTEGER}</select></mapper>

12、创建UserController.java

packagecom.example.mybatisdemo.controller;importcom.example.mybatisdemo.entity.User;importcom.example.mybatisdemo.service.UserService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.web.bind.annotation.GetMapping;importorg.springframework.web.bind.annotation.RequestParam;importorg.springframework.web.bind.annotation.RestController;@RestControllerpublicclassUserController{@AutowiredUserServiceuserService;@GetMapping("/findUserById")publicUserfindUserById(@RequestParamIntegerid){returnuserService.findUserById(1);}}

13、测试