Spring Boot & MyBatis

前面文章介绍了如何快速体验SpringBoot，但是在实际项目中作用不大，因为缺少了很多必要的组件。本文介绍如何快速接入MyBatis&MySQL

本文在一个可以运行的SpringBoot项目上增加配置，如果有疑问，可以参考SpringBoot七分钟快速实践

Spring Boot入门系列

• Spring Boot七分钟快速实践
• Spring Boot & MyBatis
• Spring Boot & Redis
• Spring Boot & Swagger
• Spring Boot & 单元测试
• Spring Boot & Actuator
• Spring Boot Admin

配置

• pom.xml

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

• application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/tenmao?useUnicode=true&characterEncoding=UTF8&zeroDateTimeBehavior=convertToNull&serverTimezone=GMT%2B8
spring.datasource.username=tenmao_user
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

驱动类使用com.mysql.cj.jdbc.Driver，而不是com.mysql.jdbc.Driver。区别参考com.mysql.jdbc.Driver 和 com.mysql.cj.jdbc.Driver的区别 serverTimezone设定

• 其他常用配置

# 开启下划线转驼峰        
mybatis.configuration.map-underscore-to-camel-case=true
# 设置mapper文件路径
mybatis.mapper-locations=classpath:mapper/*.Mapper.xml
# 设置TypeHandler包名
mybatis.type-handlers-package=com.tenmao.handler

• XxxMapper
  在各个XxxMapper（也可以是XxxDao接口）接口上添加注解org.apache.ibatis.annotations.Mapper

@Mapper
public interface PersonMapper {
    @Select("SELECT * FROM person WHERE id=#{id}")
    Person getOne(@Param("id") int id);
}

注意事项

• 可以开启debug模式，方便分析错误原因：application.properties中添加一行debug=true

常见错误

• No MyBatis mapper was found in '[com.tenmao]' package: 需要在XxxMapper接口上添加注解org.apache.ibatis.annotations.Mapper
• DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class：忘记配置spring.datasource.url了
• RuntimeException: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader：pom文件中需要添加依赖mysql-connector-java
• InvalidConnectionAttributeException: The server time zone value 'Öйú±ê׼ʱ¼ä' is unrecognized or represents more than one time zone.： 需要在配置项spring.datasource.url配置中添加serverTimezone=GMT%2B8（东八区）

参考

com.mysql.jdbc.Driver 和 com.mysql.cj.jdbc.Driver的区别 serverTimezone设定