Spring Boot + MyBatis

一、配置依赖

<!-- MyBatis -->
<dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>3.5.3</version>
</dependency>
<!-- junit测试依赖 -->
<dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope>
</dependency>
<!-- lombok依赖 为了简化实体类的编写代码量 -->
<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId>
</dependency>

不知道为什么，maven配置的远程仓库(阿里云)一直找不到org.mybatis.spring.boot: mybatis-spring-boot-starter，报如下错误：

Cannot resolve org.mybatis.spring.boot:mybatis-spring-boot-starter:unknown

最终的解决方案是使用MyBatis-plus来替代MyBatis，所以最终使用的是如下依赖信息：

<!-- MyBatis Plus-->
<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.4.1</version>
</dependency>
<!-- junit测试依赖 -->
<dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope>
</dependency>
<!-- lombok依赖 为了简化实体类的编写代码量 -->
<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId>
</dependency>

二、配置文件信息

如果是SpringBoot，在resources目录下创建application.yml文件，这个文件中存放mybaits的相关配置信息。

# 配置数据库的连接字符串
spring:datasource:url: jdbc:mysql://127.0.0.1:3306/你的数据库?characterEncoding=utf8username: 你的数据库用户名password: 你的数据库密码driver-class-name: com.mysql.cj.jdbc.Driver# 设置 Mybatis 的 xml 保存路径
mybatis:mapper-locations: classpath:mapper/*Mapper.xml #实现mapper.java接口和mapper.xml的绑定type-aliases-package: com.xj.dao.model #解释参考里有说明configuration: # 配置打印 MyBatis 执行的 SQLlog-impl: org.apache.ibatis.logging.stdout.StdOutImpl #需要lombok框架支持，可以添加# 配置打印 MyBatis 执行的 SQL
logging:level:com:example:demo: debug

三、项目举例

1.创建一个Spring Boot项目

参考：Spring Boot之创建一个Spring Boot项目（一）_<plugin> <groupid>org.springframework.boot</groupi-CSDN博客

2.项目架构

3.代码实现

pom.xml:

<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.xj</groupId><artifactId>SpringBootStudyProject</artifactId><version>1.0-SNAPSHOT</version><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.4.5</version><relativePath/></parent><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!--导入JDBC的场景启动器--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jdbc</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId><optional>true</optional></dependency><!--jquery引入--><dependency><groupId>org.webjars</groupId><artifactId>jquery</artifactId><version>3.6.0</version></dependency><!--Thymeleaf 启动器--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-thymeleaf</artifactId></dependency><!--导入数据库驱动--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><!-- MyBatis Plus--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.4.1</version></dependency><!-- junit测试依赖 --><dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope></dependency><!-- lombok依赖 为了简化实体类的编写代码量 --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies><!--build标签描述了如何来编译及打包项目，而具体的编译和打包工作是通过build中配置的 plugin 来完成--><build><plugins><!--使用SpringBoot的打包插件--><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><executions><execution><goals><goal>repackage</goal></goals></execution></executions></plugin></plugins></build>
</project>

application.yml:

#默认配置
server:port: 8080spring:datasource: #数据源连接信息username: rootpassword: 12345url: jdbc:mysql://127.0.0.1:3306/demo?useUnicode=true&characterEncoding=UTF-8driver-class-name: com.mysql.cj.jdbc.Driverprofiles:active: dev #切换配置,指定使用哪个profile# 设置 Mybatis 的 xml 保存路径
mybatis-plus:mapper-locations: classpath:mapper/*Mapper.xmltype-aliases-package: com.xj.dao.modelconfiguration: # 配置打印 MyBatis 执行的 SQLlog-impl: org.apache.ibatis.logging.stdout.StdOutImpl #需要lombok框架支持，可以添加# 配置打印 MyBatis 执行的 SQL
logging:level:com:example:demo: debug---
#开发环境
server:port: 8081spring:config:activate:on-profile: dev
---
#测试环境
server:port: 8082spring:config:activate:on-profile: test
---
#生产环境
server:port: 8083spring:config:activate:on-profile: prodlogging:config: classpath:logback-spring.xml #指定使用哪个日志配置文件

Student.java:

package com.xj.dao.model;import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
import org.springframework.data.relational.core.mapping.Column;
import java.io.Serializable;/*** @Author: xjfu* @Create: 2024/03/25 16:20* @Description:*/
@Data
public class Student implements Serializable {private static final long serialVersionUID = 1L;@TableId(value = "name")private String name;@Column(value = "age")private Integer age;
}

StudentMapper.java:

package com.xj.dao.mapper;import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.xj.dao.model.Student;
import org.springframework.stereotype.Repository;
import java.util.List;/*** @Author: xjfu* @Create: 2024/03/25 16:26* @Description:*/
@Repository
public interface StudentMapper extends BaseMapper<Student> {public List<Student> selectAll();
}

StudentMapper.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xj.dao.mapper.StudentMapper"><resultMap id="BaseResultMap" type="com.xj.dao.model.Student"><result column="name" property="name" /><result column="age" property="age" /></resultMap><select id="selectAll" resultType="com.xj.dao.model.Student">SELECT *FROM student;</select></mapper>

MainApplication.java:

package com.xj.main;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;/*** @Author : xjfu* @Date : 2022/6/8 8:38* @Description :Spring Boot 启动类*/
@ComponentScan("com.xj")
@SpringBootApplication
@MapperScan("com.xj.dao.mapper")
public class MainApplication {public static void main(String[] args) {try{SpringApplication.run(MainApplication.class, args);}catch (Exception e){e.printStackTrace();}}
}

MyBatisTest:

package com.xj.main;import com.xj.dao.mapper.StudentMapper;
import com.xj.dao.model.Student;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.sql.SQLException;
import java.util.List;/*** @Author : xjfu* @Date : 2024/3/35 16:34* @Description : MyBatis 测试类*/
@SpringBootTest(classes = MainApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class MyBatisTest {private static final Logger log = LoggerFactory.getLogger(MyBatisTest.class);@AutowiredStudentMapper studentMapper;@Testvoid testJdbc() throws SQLException{List<Student> students = studentMapper.selectAll();for (Student s : students){System.out.println(s.toString());}}
}

数据库：

CREATE TABLE `student` (`name` varchar(255) DEFAULT NULL,`age` int DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

4.运行结果

四、参考

1.在 SpringBoot 中初步使用 MyBatis_springboot mybatis-CSDN博客

2.SpringBoot结合MyBatis 【超详细】_springboot mybatis-CSDN博客

3.Cannot resolve org.mybatis.spring.bootmybatis-spring-boot-_cannot resolve org.mybatis.spring.boot:mybatis-spr-CSDN博客

4.SpringBoot：CONDITIONS EVALUATION REPORT-CSDN博客

5.@MapperScan注解使用-CSDN博客

6.mybatis的mapper-locations配置_mapperlocations属性怎么配置-CSDN博客

7.type-aliases-package的用法-CSDN博客

8.什么是MyBatis-CSDN博客

9.mybatis – MyBatis 3 | XML 映射器