From: Marius Bogoevici <mariusb(a)redhat.com&gt; Subject: Re: [weld-dev] Automatic non contextual injection using bytecode instrumentation To: "Stuart Douglas" <stuart.w.douglas(a)gmail.com&gt; Cc: "Weld" <weld-dev(a)lists.jboss.org&gt; Date: Sunday, November 14, 2010, 11:08 PM I think it would be something nice to have. For example, Spring does this via @Configurable, backed by AspectJ. I think that exploring bytecode instrumentation would be interesting for Weld,and I have for some time considered the possibility of using it as an option for interception/decoration as well. Regarding javaagent: for certain classloaders that support instrumentation and registering a ClassFileTransformer directly, we may forgo using a javaagent altogether and register the transformer during the bootstrap process. In the least, this would possible with Tomcat, Glassfish(partly) and JBoss. On 2010-11-14, at 5:35 PM, Stuart Douglas wrote: > I just had an idea for something that I think would be rather cool, > and allow objects created using new to be injected automatically. > > Conceptually it would look something like this: > > @AutoInject > public class AccountService > { >  private final Account account; > >  @Inject >  private PaymentProcessor paymentProcessor; > >  AccountService(Account account) >  { >    this.account = account; >  } > >  public void doPayment(double amount) >  { >    paymentProcessor.processPayment(account, amount); >  } > } > > We could then create the object using new and the fields will still be injected: > > AccountService a = new AccountService(account); > a.doPayment(10); > > To implement this will require a javaagent, which will modify the > bytecode of @AutoInject annotated classes as they are loaded, so that > the constructor bytecode looks up the values to inject and sets the > injected field values appropriately. Would this be something that is > worth putting into weld extensions? > > Stuart > _______________________________________________ > weld-dev mailing list > weld-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/weld-dev _______________________________________________ weld-dev mailing list weld-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/weld-dev

On Sun, Nov 14, 2010 at 6:08 PM, Marius Bogoevici <mariusb(a)redhat.com <mailto:mariusb@redhat.com>> wrote: I think it would be something nice to have. For example, Spring does this via @Configurable, backed by AspectJ. I've been asked about support for something akin to @Configurable after numerous presentations I've given on CDI. I wasn't quite clear what @Configurable was all about, but now I see. So yes, we could say that this has been a frequently requested feature and would definitely be worth exploring. ...in fact, as I was walking today, I thought to myself "is the new keyword dead? what was it like when we had to use it?". This brings everything back full circle so that you can still create objects in the classic way, but benefit from modern programming model patterns. Quite brilliant.

-Dan -- Dan Allen Principal Software Engineer, Red Hat | Author of Seam in Action Registered Linux User #231597 http://mojavelinux.com http://mojavelinux.com/seaminaction http://www.google.com/profiles/dan.j.allen _______________________________________________ weld-dev mailing list weld-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/weld-dev