mybatis学习（五）Spring整合mybatis 映射器注入

             mybatis映射器机制，我们只需要定义好借口，mybatis帮我创建实现类，并且来管理SqlSession对象的创建和关闭，减少我们不少工作。缺点能就是不太够灵活。mybatis映射器注入可以选择两种方式，一种依赖MapperFactoryBean，另外一种方式依赖MapperScannerConfigure。

            MapperFactoryBean

            首先定义一个映射器,映射器是一个接口

public interface MusicMapper {

	/**
	 * 
	 * @description TODO
	 * @param id
	 * @return
	 * @return Music
	 */
	@Results(id = "musicResult", value = {
			@Result(property = "id", column = "id", id = true),
			@Result(property = "name", column = "name"),
			@Result(property = "singer", column = "singer"),
			@Result(property = "album", column = "album"),
			@Result(property = "duration", column = "duration"),
			@Result(property = "author", column = "author"),
			@Result(property = "composer", column = "composer"),
			@Result(property = "style", column = "style") })
	@Select("select * from t_music where id= #{id}")
	public Music getMusicById(@Param("id") String id);
	/**
	 * id; name; singer;
	 * 
	 * album; duration; author; composer;style
	 */
}

          在Spring配置映射器，要将映射器注入到Service实现类中

<bean id="musicMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
  		<property name="mapperInterface" value="org.lian.mapper.MusicMapper" />
		<property name="sqlSessionFactory" ref="sqlSessionFactory" />
	</bean>
	
	<bean id="musicService" class="org.lian.service.impl.MusicServiceImpl">
         <property name="musicMapper" ref="musicMapper"/>
    </bean>

            当映射器很多的时候，像上面的配置似乎会让配置显得更加臃肿，那么采用下面的方式就可以简化上面的配置

            MapperScannerConfigure

            采用下面的配置可以省略配置很多Mapper映射器

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<!--如果是多个包  org.lian.dao;org.lian.mapper;...;*     
		org.lian.dao,org.lian.mapper....,* 使用,或者;分隔-->
		<property name="basePackage" value="org.lian.mapper" />
		<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
	</bean>
	
	<bean id="musicService" class="org.lian.service.impl.MusicServiceImpl">
         <property name="musicMapper" ref="musicMapper"/>
    </bean>
	

          采用上面的方式有一个要求就musicMapper要和映射器接口MusicMapper要保持一致，如果想要更加灵活可以使用Spring的@Component或者JSR-330 的@Named 注解，Spring其他注解没有测试,除此之外还有其他的注解那需要配置MapperScannerConfigure的annotationClass 属性指定了要寻找的注解名称。

          

@Component("groupDao")
public interface GroupMapper {

	@Results(id = "groupResult", value = {
			@Result(property = "groupId", column = "group_id", id = true),
			@Result(property = "groupName", column = "group_name") })
	@Select("select * from t_group where group_id= #{groupId} ")
	public Group getGroupById(String groupId);

}

 

@Service("groupService")
public class GroupServiceImpl implements GroupService {

	private GroupMapper groupDao;

	@Override
	public Group getGroupById(String groupId) {
		return groupDao.getGroupById(groupId);
	}

	public GroupMapper getGroupDao() {
		return groupDao;
	}

	@Resource(name = "groupDao")
	public void setGroupDao(GroupMapper groupDao) {
		this.groupDao = groupDao;
	}

}

 

    Spring整合mybatis官网给出了更加详尽的内容，需要的查询的可以参考Spring-mybatis官网