2.1、Maven 安装如下：
org.mybatis.spring.boot
mybatis-spring-boot-starter
2.1.1
2.2、Gradle 安装如下：
dependencies {
compile("org.mybatis.spring.boot:mybatis-spring-boot-starter:2.1.1")
}
众所周知，MyBatis的核心有两大组件：SqlSessionFactory 和 Mapper 接口。前者表示数据库链接，后者表示SQL映射。当我们基于Spring使用MyBatis的时候，也要保证在Spring环境中能存在着两大组件。
MyBatis-Spring-Boot-Starter 将会完成以下功能:
1、Autodetect an existing DataSource
自动发现存在的DataSource
2、Will create and register an instance of a SqlSessionFactory passing that DataSource as an input using the SqlSessionFactoryBean
利用SqlSessionFactoryBean创建并注册SqlSessionFactory
3、Will create and register an instance of a SqlSessionTemplate got out of the SqlSessionFactory
创建并注册SqlSessionTemplate
4、Auto-scan your mappers, link them to the SqlSessionTemplate and register them to Spring context so they can be injected into your beans
自动扫描Mappers，并注册到Spring上下文环境方便程序的注入使用
MyBatis-Spring-Boot-Starter会自动找到被@Mapper注解的接口。使用@MapperScan可以指定Mapper接口的位置，免去每个接口都要@Mapper
可以获取sqlSession，具体为SqlSessionTemplate的一个实例。
@Component
public class CityDao {
private final SqlSession sqlSession;
public CityDao(SqlSession sqlSession) {
this.sqlSession = sqlSession;
}
public City selectCityById(long id) {
return this.sqlSession.selectOne("selectCityById", id);
}
}
如果你熟悉xml配置文件的话，都能看懂的。
yml或properties中的可选配置，以mybatis开头
Property Description
config-location xml配置文件的位置
check-config-location Indicates whether perform presence check of the MyBatis xml config file.
mapper-locations xml映射器的位置
type-aliases-package Packages to search for type aliases. (Package delimiters are “,;
”)
type-aliases-super-type The super class for filtering type alias. If this not specifies, the MyBatis deal as type alias all classes that searched from type-aliases-package.
type-handlers-package Packages to search for type handlers. (Package delimiters are “,;
”)
executor-type Executor type: SIMPLE, REUSE, BATCH
default-scripting-language-driver The default scripting language driver class. This feature requires to use together with mybatis-spring 2.0.2+.
configuration-properties Externalized properties for MyBatis configuration. Specified properties can be used as placeholder on MyBatis config file and Mapper file. For detail see the MyBatis reference page.
lazy-initialization Whether enable lazy initialization of mapper bean. Set true to enable lazy initialization. This feature requires to use together with mybatis-spring 2.0.2+.
mapper-default-scope Default scope for mapper bean that scanned by auto-configure. This feature requires to use together with mybatis-spring 2.0.6+.
mybatis.inject-sql-session-on-mapper-scan Set whether inject a SqlSessionTemplate or SqlSessionFactory bean (If you want to back to the behavior of 2.2.1 or before, specify false). If you use together with spring-native, should be set true(default).
configuration.* Property keys for Configuration bean provided by MyBatis Core. About available nested properties see the MyBatis reference page. NOTE: This property cannot be used at the same time with the config-location.
scripting-language-driver.thymeleaf.* Property keys for ThymeleafLanguageDriverConfig bean provided by MyBatis Thymeleaf. About available nested properties see the MyBatis Thymeleaf reference page.
scripting-language-driver.freemarker.* Properties keys for FreeMarkerLanguageDriverConfig bean provided by MyBatis FreeMarker. About available nested properties see the MyBatis FreeMarker reference page. This feature requires to use together with mybatis-freemarker 1.2.0+.
scripting-language-driver.velocity.* Properties keys for VelocityLanguageDriverConfig bean provided by MyBatis Velocity. About available nested properties see the MyBatis Velocity reference page. This feature requires to use together with mybatis-velocity 2.1.0+.
MyBatis-Spring-Boot-Starter 提供了自定义 MyBatis 配置的机会，该配置由使用 Java Config 自动配置生成。 MyBatis-Spring-Boot-Starter 会自动搜索实现 ConfigurationCustomizer 接口的 bean，并调用customize方法。 （自 1.2.1 或更高版本可用
@Configuration
public class MyBatisConfig {
@Bean
ConfigurationCustomizer mybatisConfigurationCustomizer() {
return new ConfigurationCustomizer() {
@Override
public void customize(Configuration configuration) {
// customize ...
}
};
}
}
对于SqlSessionFactoryBean，MyBatis-Spring-Boot-Starter 提供了使用 Java Config 自定义自动配置生成的机会。MyBatis-Spring-Boot-Starter 会自动搜索实现了SqlSessionFactoryBeanCustomizer接口的 bean，并调用其customize方法。 （自 2.2.2 或更高版本可用）
@Configuration
public class MyBatisConfig {
@Bean
SqlSessionFactoryBeanCustomizer sqlSessionFactoryBeanCustomizer() {
return new SqlSessionFactoryBeanCustomizer() {
@Override
public void customize(SqlSessionFactoryBean factoryBean) {
// customize ...
}
};
}
}
当使用多个数据源时
@Configuration
public class MyBatisConfig {
@Bean
public SqlSessionFactory masterSqlSessionFactory() throws Exception {
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(masterDataSource());
factoryBean.setVfs(SpringBootVFS.class); // Sets the SpringBootVFS class into SqlSessionFactoryBean
// ...
return factoryBean.getObject();
}
}
MyBatis-Spring-Boot-Starter 将检测实现 MyBatis 提供的以下接口的 bean。
Interceptor
TypeHandler
LanguageDriver（需要配合mybatis-spring 2.0.2+使用）
DatabaseIdProvider
@Configuration
public class MyBatisConfig {
@Bean
MyInterceptor myInterceptor() {
return MyInterceptor();
}
@Bean
MyTypeHandler myTypeHandler() {
return MyTypeHandler();
}
@Bean
MyLanguageDriver myLanguageDriver() {
return MyLanguageDriver();
}
@Bean
VendorDatabaseIdProvider databaseIdProvider() {
VendorDatabaseIdProvider databaseIdProvider = new VendorDatabaseIdProvider();
Properties properties = new Properties();
properties.put("SQL Server", "sqlserver");
properties.put("DB2", "db2");
properties.put("H2", "h2");
databaseIdProvider.setProperties(properties);
return databaseIdProvider;
}
}
如果您想自定义LanguageDriver通过自动配置创建的，请注册用户定义的 bean。
@Configuration
public class MyBatisConfig {
@Bean
ThymeleafLanguageDriverConfig thymeleafLanguageDriverConfig() {
return ThymeleafLanguageDriverConfig.newInstance(c -> {
// ... customization code
});
}
}