XML and annotations

[bazi]

Hi,

I have a problem. I always used XML file to configure the container. Now we have, annoations. But still XML is more powerfull than annotatations. I wonder how to mix that two configurations i.e. Can I define bean via @Comoponent and then override properties via XML.

Thanks for your help

[soks86]

If you have

<context:annotation-config />

in your XML then any @Component will @Autowire anything that's marked as such if you don't set the values yourself manually.

Also you can use XML in your @Configuration's using @ImportResource.

http://static.springsource.org/sprin...eference/html/

Check that document from section 3.9 through 3.14 to see what you can do.

[bazi]

Thanks,

But I talked about XML-centric configuration.
For example: I annotaded a bean as @Component, and how to address it from XML descriptor. I've done some experiments ant it turned out that when you use the same id in @Component annotation and XML file, the container creates only one object. But it is not documented feature

@Component
class Service {}

and XML

<beans ...>
//component scan and stuff

<bean id="service" class="my.Service" /> -- here I addressed component via the XML descriptor
</beans>

I noticed than XML has higher priority than annotation, ie: when you use @Value to init value of the property and <property/> tag at the same time, the XML definition wins.

Do you know what I mean?

[soks86]

I think I understand your confusion.

There is no direct way to access @Component's and their children. The idea of scanning for @Components is supposed to be used along with @Autowire which together allows you to omit XML configuration. Perhaps this makes more sense when you realize there is an @Scope annotation as well to define a @Components scope.

As for creating one object, how did you test what object was created with the auto scan? I don't think Spring would even bother with the @Component if there are no references to it.

If you want XML-centric WITH @Components then I believe the goal would be to @Component/@Autowire annotate as much of your code as possible then only define the beans that you need to set/get manually. This way you write only the XML code that you need and the rest of your instances are autowired on their own.

Any XML or @Bean setting/injection will usually override (if not always) your @Autowire, @Qualify, and @Value annotations.

[bazi]

Now I understand,

Thanks Master