Dependency injection and Aggregates

[Stanislav Kurilin]

Could I really inject something in my Aggregate root using Spring?
By now, I have aggregate with 2 constructors, like

     @CommandHandler
     public Foo(MyCommand c){}

     private Foo(){}

and tests with fixtures.

What I want is
     @CommandHandler
     public Foo(MyCommand c, Injected i){}

     private Foo(Injected i){}

and some way to pass specified value for Injected  in fixtures.

Or should I separate CommandHandler from aggregate and use setters for injection to make it work with axon?

[bui...@gmail.com]

Hi,

unfortunately, constructor injection in combination with aggregate command handlers is not supported.

You can currently only do setter injection, or use the a SpringPrototypeAggregateFactory to create aggregate instances. But that won't work with @commandhandler annotated aggregates.

Cheers,

Allard

[Allard Buijze]

Hi,

I just had an idea. In Axon 2, I use ParameterResolvers to get the values for the parameters of @CommandHandler (and @EventHandler) annotated method. I could create one that injects beans from an application context into these methods. That should solve this problem.

I've created issue AXON-25 to solve this.

Cheers,

Allard

[Stanislav Kurilin]

Hi,

Thanks for your work. I was thinking about ParameterResolvers too. But I think more general solution needed than just creating ApplicationContextSpringResolver since it's doesn't solve fixture issue and could not be comparative with non spring application. 

[bui...@gmail.com]

Hi,

I have created AXON-26 to address similar support in test fixtures. 

Cheers,

Allard

[Stanislav Kurilin]

Hi. Thanks a lot.