Question

I read about Compound property names in the “The Spring Framework (2.5) – Reference Documentation – chapter 3.3.2.7“

Can i use the same concept to set values of properties? Can i use a compound string as a value expression?

<bean id="service1" class="a.b.c.Service1Impl" scope="prototype">
   <property name="service2" ref="service2"/>
   <property name="service2.user" value="this-service1-instance.user"/> 
</bean>
<bean id="service2" class="a.b.c.Service2Impl" scope="prototype">
    ... 
</bean>

User is a property of a.b.c.Service1Impl which is not in control of Spring. I want to forward this property to a.b.c.Service2Impl.

Answer 1

Rather than use a plain old factory bean, rather use a factory method to create the bean of the property and then inject that result…

iow

in your case, it would look something like this…

<!-- the bean to be created via the factory bean -->
<bean id="exampleBean"
      factory-bean="serviceLocator"
      factory-method="createInstance"/>

So the bean of id is created by calling createInstance on bean serviceLocator.

Now spring does not support nested properties out of the box, though you could look at creating a custom editors which might provide that support – possible but tricky. Possibly not worth the effort.

One mechanism you could look at using is nesting using the factory-bean factory-method technique…

Something like:

<bean id="c" class="C" />
<bean id="b" factory-bean="c" factory-method="getB"/>
<bean id="a" factory-bean="b" factory-method="getA"/>

This will effectively expose: a.b.c where C has a method getB and A has a method getB