1. If you don't want to configure beans in the xml file, we can add spring component annotations to our classes, and just configure the spring scanner to achieve automatic bean loading.
</context:component-scan>
<!-- Annotation injection-->
<context:annotation-config></context:annotation-config>
<context:component-scan base-package="com.liantuo.hotel.common.service.impl" />
<context:component-scan base-package="com.liantuo.hotel.common.dao.ibatis" />
<context:component-scan base-package="com.liantuo.hotel.app.dao.ibatis" />
<context:component-scan base-package="com.liantuo.hotel.app.service" />
<context:component-scan base-package="com.liantuo.hotel.app.service.ibatis" />
2. The following is a quote from the spring framework development manual
"
Spring 2.5 introduced more stereotype annotations:
@Component
,
@Service
and
@Controller
.
@Component
is the generic form for all Spring-managed components; while
@Repository
,
@Service
and
@Controller
are
@Component
refinements used to represent more specific use cases (eg, for persistence, service, and presentation, respectively). That is, you
@Component
can annotate your component classes with , but if you annotate them with
@Repository
,
@Service
or
@Controller
, your classes may be better handled by tools, or associated with aspects. For example, these canonicalization annotations can be ideal pointcut targets. Of course, in future versions of the Spring Framework,
@Repository
,
@Service
and
@Controller
may carry more semantics. As such, if you are considering whether to use
@Component
or not in the service layer
@Service
, it
@Service
is obviously a better choice. Also, as mentioned earlier,
@Repository
it can be used as a marker for exception translation in the persistence layer. "
3.
With <context:component-scan>, another <context:annotation-config/> tag can be removed at all, because it is already included.
4.
<context:component-scan> provides two sub-tags: <context:include-filter> and <context:exclude-filter>, which represent the imported and excluded filters.
如：
<context:component-scan base-package="com.xhlx.finance.budget" >
<context:include-filter type="regex" expression=".service.*"/>
</context:component-scan>
5.
The filter tag has five types in Spring 3, as follows:
| Filter Type | Examples Expression | Description |
| annotation | org.example.SomeAnnotation | A target class that conforms to SomeAnnoation |
| assignable | org.example.SomeClass | Specify the full name of the class or interface |
| aspectj | org.example..*Service+ | AspectJ syntax |
| regex | org\.example\.Default.* | Controller Expression |
| custom | org.example.MyTypeFilter | Spring3 adds a custom Type, implements org.springframework.core.type.TypeFilter |