SpringBoot-data access-integrate MyBatis-configuration version

Introduce dependencies

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.4</version>
</dependency>

@ConditionalOnSingleCandidate(DataSource.class)

single source of truth

 SqlSessionFactory: automatically configured

  @Bean
  @ConditionalOnMissingBean
  public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
    SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
    factory.setDataSource(dataSource);
    factory.setVfs(SpringBootVFS.class);
    //xxxxxxxxxxx
}

DataSource dataSource
factory.setDataSource(dataSource);

data source

---

  @Bean
  @ConditionalOnMissingBean
  public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
    ExecutorType executorType = this.properties.getExecutorType();
    if (executorType != null) {
      return new SqlSessionTemplate(sqlSessionFactory, executorType);
    } else {
      return new SqlSessionTemplate(sqlSessionFactory);
    }
  }

 SqlSession: SqlSessionTemplate is automatically configured to combine SqlSession

---

  @org.springframework.context.annotation.Configuration
  @Import(AutoConfiguredMapperScannerRegistrar.class)
  @ConditionalOnMissingBean({ MapperFactoryBean.class, MapperScannerConfigurer.class })
  public static class MapperScannerRegistrarNotFoundConfiguration implements InitializingBean {

    @Override
    public void afterPropertiesSet() {
      logger.debug(
          "Not found configuration for registering mapper bean using @MapperScan, MapperFactoryBean and MapperScannerConfigurer.");
    }

  }

 @Import(AutoConfiguredMapperScannerRegistrar.class）；

public static class AutoConfiguredMapperScannerRegistrar implements BeanFactoryAware, ImportBeanDefinitionRegistrar {

    private BeanFactory beanFactory;

    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {

      if (!AutoConfigurationPackages.has(this.beanFactory)) {
        logger.debug("Could not determine auto-configuration package, automatic mapper scanning disabled.");
        return;
      }

      logger.debug("Searching for mappers annotated with @Mapper");

    //xxxxxxxxxxxxx

    }

}

AnnotationMetadata (annotation)

logger.debug("Searching for mappers annotated with @Mapper");

Find all interfaces with @Mapper

• Mapper: As long as the interface we write to operate MyBatis is marked with @Mapper, it will be automatically scanned in

---

classpath:

classpathIn Spring Boot, the class path/java/ refers to both the directory plus the directory of the program before packaging /resource, and the directory generated by the program after packaging /classes/. The two actually refer to the same directory, and the contents of the files contained in it are exactly the same.