spring、mybatis整合源码简单分析

<bean id="localDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
        <property name="url" value="jdbc:mysql://192.168.31.14:3366/lios?characterEncoding=utf8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
        ...
    </bean>
    <!-- 创建SqlSessionFactory，同时指定数据源-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="localDataSource"/>
        <property name="configLocation" value="classpath:sqlmap-config.xml"/>
        <property name="mapperLocations">
            <list>
               <value>classpath*:com/lios/mybatis/mapper/*.xml</value>
            </list>
        </property>
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.lios.mybatis.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>

invokeBeanFactoryPostProcessors(beanFactory);

// Finally, invoke all other BeanDefinitionRegistryPostProcessors until no further ones appear.
boolean reiterate = true;
while (reiterate) {
    reiterate = false;
    postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
    for (String ppName : postProcessorNames) {
        if (!processedBeans.contains(ppName)) {
            //getBean方法会初始化MapperScannerConfigurer
            BeanDefinitionRegistryPostProcessor pp = beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class);
            registryPostProcessors.add(pp);
            processedBeans.add(ppName);
            // 调用MapperScannerConfigurer的postProcessBeanDefinitionRegistry方法
            pp.postProcessBeanDefinitionRegistry(registry);
            reiterate = true;
        }
    }
}

...
scanner.scan(StringUtils.tokenizeToStringArray(this.basePackage, ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS));

// Register annotation config processors, if necessary.
if (this.includeAnnotationConfig) {
    AnnotationConfigUtils.registerAnnotationConfigProcessors(this.registry);
}
return (this.registry.getBeanDefinitionCount() - beanCountAtScanStart);

// 调用父类doScan方法,扫描basePackage下的mapper的接口文件,封装成Set<BeanDefinitionHolder>
doScan(basePackages);
Set<BeanDefinitionHolder> beanDefinitions = super.doScan(basePackages);
if (beanDefinitions.isEmpty()) {
  logger.warn("No MyBatis mapper was found in '" + Arrays.toString(basePackages) + "' package. Please check your configuration.");
} else {
  processBeanDefinitions(beanDefinitions);
}
return beanDefinitions;

GenericBeanDefinition definition;
for (BeanDefinitionHolder holder : beanDefinitions) {
  definition = (GenericBeanDefinition) holder.getBeanDefinition();
  // the mapper interface is the original class of the bean
  // but, the actual class of the bean is MapperFactoryBean
  definition.getConstructorArgumentValues().addGenericArgumentValue(definition.getBeanClassName()); // issue #59
  // 上面的注释其实说的很清楚了,mapper接口实际的实体为MapperFactoryBean
  definition.setBeanClass(this.mapperFactoryBean.getClass());
  // 设置MapperFactoryBean属性addToConfig元素
  definition.getPropertyValues().add("addToConfig", this.addToConfig);
  ...
  // 设置MapperFactoryBean属性sqlSessionTemplate元素
  definition.getPropertyValues().add("sqlSessionTemplate", this.sqlSessionTemplate);
}

@Autowired
UserInfoDao userInfoDao;

@Override
public void afterPropertiesSet() throws Exception {
notNull(dataSource, "Property 'dataSource' is required");
notNull(sqlSessionFactoryBuilder, "Property 'sqlSessionFactoryBuilder' is required");
state((configuration == null && configLocation == null) || !(configuration != null && configLocation != null),
          "Property 'configuration' and 'configLocation' can not specified with together");
this.sqlSessionFactory = buildSqlSessionFactory();
}

XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(mapperLocation.getInputStream(),
configuration, mapperLocation.toString(), configuration.getSqlFragments());
xmlMapperBuilder.parse();

bean = getObjectForBeanInstance(sharedInstance, name, beanName, mbd);

object = getObjectFromFactoryBean(factory, beanName, !synthetic);

Object object = doGetObjectFromFactoryBean(factory, beanName);

...
object = factory.getObject();
...

return getSqlSession().getMapper(this.mapperInterface);

final MapperProxyFactory<T> mapperProxyFactory = (MapperProxyFactory<T>) knownMappers.get(type);
if (mapperProxyFactory == null) {
  throw new BindingException("Type " + type + " is not known to the MapperRegistry.");
}
try {
  return mapperProxyFactory.newInstance(sqlSession);
} catch (Exception e) {
  throw new BindingException("Error getting mapper instance. Cause: " + e, e);
}

try {
  if (Object.class.equals(method.getDeclaringClass())) {
    return method.invoke(this, args);
  } else if (isDefaultMethod(method)) {
    return invokeDefaultMethod(proxy, method, args);
  }
} catch (Throwable t) {
  throw ExceptionUtil.unwrapThrowable(t);
}
final MapperMethod mapperMethod = cachedMapperMethod(method);
return mapperMethod.execute(sqlSession, args);

@Override
  protected void checkDaoConfig() {
    super.checkDaoConfig();
    notNull(this.mapperInterface, "Property 'mapperInterface' is required");
    // mybatis中配置类
    Configuration configuration = getSqlSession().getConfiguration();
    if (this.addToConfig && !configuration.hasMapper(this.mapperInterface)) {
      try {
        // 添加mapper关联
        configuration.addMapper(this.mapperInterface);
      } catch (Exception e) {
        logger.error("Error while adding the mapper '" + this.mapperInterface + "' to configuration.", e);
        throw new IllegalArgumentException(e);
      } finally {
        ErrorContext.instance().reset();
      }
    }
  }