Spring源码：spring-mybatis重要类

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配置一：

<bean id="defaultSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="defaultDataSource" />
    <property name="mapperLocations">
        <array>
            <value>classpath*:dal/mapper/**/*.xml</value>
            <value>classpath*:mapper/*.xml</value>
        </array>
    </property>
    <property name="configLocation" value="classpath:dal/youzan-ibatisCfg.xml" />
    <property name="typeAliasesPackage" value="com.youzan.ump.marketing.dal.*.dataobject"/>
</bean>

<bean id="pointDeductionMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
    <property name="mapperInterface" value="com.mapper.pointdeduction.PointDeductionMapper"/>
    <property name="sqlSessionFactory" ref="defaultSqlSessionFactory"/>
</bean>

<bean id="pointDeductionRecordMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
    <property name="mapperInterface" value="com.mapper.pointdeduction.PointDeductionRecordMapper"/>
    <property name="sqlSessionFactory" ref="defaultSqlSessionFactory"/>
</bean>

配置二：

<bean id="defaultSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="defaultDataSource" />
    <property name="mapperLocations">
        <array>
            <value>classpath*:dal/mapper/**/*.xml</value>
            <value>classpath*:mapper/*.xml</value>
        </array>
    </property>
    <property name="configLocation" value="classpath:dal/youzan-ibatisCfg.xml" />
    <property name="typeAliasesPackage" value="com.youzan.ump.marketing.dal.*.dataobject"/>
</bean>

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.mapper" />
    <property name="sqlSessionFactoryBeanName" ref="defaultSqlSessionFactory" />
</bean>

• SqlSessionFactoryBean结构

  public class SqlSessionFactoryBean implements FactoryBean<SqlSessionFactory>, InitializingBean, ApplicationListener<ApplicationEvent>{
      private Resource configLocation; // mybatis配置文件位置
      private Resource[] mapperLocations; // mapper文件位置
      private DataSource dataSource;      // 数据源
      private TransactionFactory transactionFactory;
      private Properties configurationProperties;
      private SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
      private SqlSessionFactory sqlSessionFactory;
      private String environment = SqlSessionFactoryBean.class.getSimpleName();
      private boolean failFast;
      private Interceptor[] plugins;
      private TypeHandler<?>[] typeHandlers;
      private String typeHandlersPackage;
      private Class<?>[] typeAliases;
      private String typeAliasesPackage;
      private Class<?> typeAliasesSuperType;
      private DatabaseIdProvider databaseIdProvider;
      private ObjectFactory objectFactory;
      private ObjectWrapperFactory objectWrapperFactory;
      //.......
  }
  

  该类可以取代mybatis的配置，直接注入属性值，即你完全可以取消配置中的configLocation属性，而把其中的属性直接写在SqlSessionFactoryBean中

• SqlSessionFactoryBuilder：用于构造SqlSessionFactory

• SqlSessionFactory：创建SqlSession的工厂，默认实现是DefaultSqlSessionFactory

  SqlSessionFactory是MyBatis的关键对象,它是个单个数据库映射关系经过编译后的内存镜像.SqlSessionFactory对象的实例可以通过SqlSessionFactoryBuilder对象类获得,而SqlSessionFactoryBuilder则可以从XML配置文件或一个预先定制的Configuration的实例构建出SqlSessionFactory的实例.每一个MyBatis的应用程序都以一个SqlSessionFactory对象的实例为核心.同时SqlSessionFactory也是线程安全的,SqlSessionFactory一旦被创建,应该在应用执行期间都存在.在应用运行期间不要重复创建多次,建议使用单例模式

• MapperFactoryBean：MapperFactoryBean的出现为了代替手工使用SqlSessionDaoSupport或SqlSessionTemplate编写数据访问对象(DAO)的代码,使用动态代理实现

  public class MapperFactoryBean<T> extends SqlSessionDaoSupport implements FactoryBean<T> {
    private Class<T> mapperInterface;
    // ......
  }
  

• MapperScannerConfigurer：查找类路径下的映射器并自动将它们创建成MapperFactoryBean。

  public class MapperScannerConfigurer implements BeanDefinitionRegistryPostProcessor, InitializingBean, ApplicationContextAware, BeanNameAware {
  
  private String basePackage;
  
  private SqlSessionFactory sqlSessionFactory;
  
  private SqlSessionTemplate sqlSessionTemplate;
  
  private String sqlSessionFactoryBeanName;
  
  //......
  }