I don't have time to do a point-by-point response to this at the
moment, but I'm currently at the DevNexus conference in Atlanta. I
was just talking to Keith Donald of SpringSource and watching his
presentation, and he spent considerable time talking about how they
view annotations as the best practice when using Spring. From Spring
3.0 going forward, annotations will be the best practice and will be
communicated as such in their documentation. There are definitely
ways to work around the concerns you brought up, such as configuring
your application differently in different contexts. If you want, I
can try to do a point-by-point analysis later, but the SpringSource
guys know their stuff and are very clear that annotations are the best
practice.
On Mar 11, 2009, at 11:10 AM, Les Hazlewood wrote:
Yeah, I didn't mean the example per se, but you had mentioned best
(or maybe
just current) practices before.
Of course annotations clean up xml significantly, but I'm not so
sure that
they are a 'best practice'. It is convenient for many, sure, but it
has
downsides that might preclude it from being used.
For example, I encountered something just 2 days ago that required a
configuration change from something that was running in a publicly
available
beta environment. We were stuck for time and we couldn't re-build the
project. We were able to go in, change a config file, restart
Tomcat, and
the stake holder was quite happy. We couldn't have done that with
annotations.
And there is another thing about annotations that I'm not too keen
on - the
required mix of XML and Annotations. For large projects, some of
your beans
can be annotation configured, while many others cannot (Hibernate
session
factory, connection pool, 'frameworky' proxy stuff, prototype scoped
beans,
etc). Then you'll have to hunt down which objects are configured in
one way
vs another. I like consistency, especially when 20+ developers have
their
hands in the mix.
I honestly haven't made up my mind about this issue. I like the
cleanliness
of annotations, but I wonder what would happen if dynamic
configuration
would be required in a pinch. That it saved my team's arse only 2
days ago
leads me to believe it might happen again, and having that in my
back pocket
is really comforting...
On Wed, Mar 11, 2009 at 10:28 AM, Jeremy Haile <[email protected]>
wrote:
I think using annotations to configure Spring singletons is very
nice - it
minimizes XML while still allowing you to configure things in XML
when
desired. This seems to be the trend in Spring usage as well, as
Spring 3.0
will be very focused on the annotation configuration support - in
fact
Spring MVC will be deprecating all XML configuration of controllers
in favor
of annotations.
Look how simple the Spring XML files are in the project. I think
it's nice
to have an example app that shows off the latest Spring technology
as well.
I think it's debatable as to whether annotations "couple" you to
Spring -
obviously the JAR file is required, but there's no reason I couldn't
dependency inject them using some other framework. Spring won't
even create
these singletons unless I tell it to in the XML file using the
context:component-scan tag, so they can be configured differently
in a "unit
test" context, etc.. That being said, I'm not worried about it being
"coupled to Spring" since it is the spring-hibernate example.
Jeremy
On Mar 9, 2009, at 10:09 AM, Les Hazlewood wrote:
Hi Jeremy,
Why did you decide to use Spring Annotations to wire your objects
instead
of
autowiring? Now most of the business objects/DAOs in the sample
app are
coupled to Spring's API. I'm curious as to why you went down that
road...
Les
