@Component with parent?

Question

Is there any way to use <bean parent="someParent"> with @Component annotation (creating spring beans using annotation)?

I would like to create spring bean that has "spring parent" using @Component annotation.

is it possible?

Answer 1

Following my comment, this piece of XML

<bean id="base" abstract="true">
    <property name="foo" ref="bar"/>
</bean>

<bean class="Wallace" parent="base"/>
<bean class="Gromit" parent="base"/>

is more or less eqivalent to this code (note that I created artificial Base class since abstract beans in Spring don't need a class):

public abstract class Base {
    @Autowired
    protected Foo foo;
}

@Component
public class Wallace extends Base {}

@Component
public class Gromit extends Base {}

Wallace and Gromit now have access to common Foo property. Also you can override it, e.g. in @PostConstruct.

BTW I really liked parent feature in XML which allowed to keep beans DRY, but Java approach seems even cleaner.

Answer 2

Just came across the same Construct.. (a general abstract parent Class which used Beans - with context.xml-declaration for an potential Implementation that was injected by Component-scan)

This is what I could have done in the @Component Class:

@Autowired
public void setBeanUsedInParent(BeanUsedInParent bean) {
   super.setBeanUsedInParent(bean);
}

---

..what I ended up doing (better, since it makes clear that the injection works on the object not on classes) - and if you are able to modify the parent Class:

// abstract getter in parent Class
public abstract BeanUsedInParent getBeanUsedInParent();

..leave the actual Beans as well as their injection up to the actual implementation (the @Component Class):

@Autowired
private BeanUsedInParent beanUsedInParent;

@Override
public BeanUsedInParent getBeanUsedInParent() {
   return this.beanUsedInParent;
}