spring-mapper代理对象的创建

引言

使用spring全家桶一段时间了，ioc的前后接口也稍微有些了解，比较好奇mybatis中如何将mapper代理
此文基于 mybatis-spring 源码做分析

mapper代理对象创建的全流程

重要的类

mapper工厂bean

MapperFactoryBean继承了SqlSessionDaoSupport 实现了 FactoryBean,其继承关系如下：

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/**
 * BeanFactory that enables injection of MyBatis mapper interfaces.
 * It can be set up with a SqlSessionFactory or a
 * pre-configured SqlSessionTemplate.
 */
public class MapperFactoryBean<T> extends SqlSessionDaoSupport implements FactoryBean<T>

public abstract class SqlSessionDaoSupport extends DaoSupport

public abstract class DaoSupport implements InitializingBean

mapperScannerConfigure

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public class MapperScannerConfigurer
    implements BeanDefinitionRegistryPostProcessor, InitializingBean, ApplicationContextAware, BeanNameAware{

}

mapperFactoryBean

checkDaoConfig方法将mapperInterface写入到sqlSession

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private Class<T> mapperInterface;


  /**
   * 其在DaoSupport中 afterPropertiesSet中被调用
   */
  @Override
  protected void checkDaoConfig() {
    super.checkDaoConfig();

    notNull(this.mapperInterface, "Property 'mapperInterface' is required");

    Configuration configuration = getSqlSession().getConfiguration();
    if (this.addToConfig && !configuration.hasMapper(this.mapperInterface)) {
      try {
        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();
      }
    }
  }