I have two abstract classes
class abstract A {
//some methods .
}
class abstract B extends A {
private C c ;
//other methods
}
Spring config file :
<bean id="b" class="B" abstract="true">
<property name="c" ref="C" /> //I have reference for C else where
</bean>
When I run the program , the class c is not getting injected . It is coming as null . Am i missing something ?
abstract=true
means that the bean specification is a 'template' for other bean declarations to extend, it does not mean the class is abstract. I suspect bean with id b
is not being created since it is a template/abstract definition. Remove abstract=true
and make B
a concrete type and it should work.
Documentation here: http://static.springsource.org/spring/docs/3.0.x/reference/beans.html#beans-child-bean-definitions
Although the use of 'abstract="true"' is not meant to indicate that the bean specification is for an abstract class, it is still required for an abstract class bean definition so that pre-instantiation is not attempted on that class (which would fail for an abstract class). This is indicated in a note below the section that the above link points to (http://static.springsource.org/spring/docs/3.0.x/reference/beans.html#beans-child-bean-definitions). If this were a situation where the super class was not an abstract class, then yes, 'abstract="true"' should not be used.
You don't show a setter for C in the abstract class B. You must use either setting or constructor injection. The code as posted can't work.
You should also specify B as the parent bean for C; likewise A for B.
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