Inject spring dependency in abstract super class

Question

I have requirement to inject dependency in abstract superclass using spring framework.

class A extends AbstractClassB{      private Xdao daox ;     ...     public setXdao() { ... } }  class AbstractClassB{     ..     private yDao  daoy;     public seyYdao() { ... } } 

I need to pass superclass dependency everytime i instantiate Abstract class B (which can be subclassed in 100's of ways in my project)

entry in application.xml (spring context file)

<bean id="aClass" class="com.mypro.A"      <property name="daox" ref="SomeXDaoClassRef" />      <property name="daoy" ref="SomeYDaoClassRef"/> </bean> 

How can i just create bean reference of super class AbstractClassB in application.xml so that i can use it in all subclass bean creation?

Answer 1

You can create an abstract bean definition, and then "subtype" that definition, e.g.

<bean id="b" abstract="true" class="com.mypro.AbstractClassB">     <property name="daox" ref="SomeXDaoClassRef" />  </bean>  <bean id="a" parent="b" class="com.mypro.A">     <property name="daoy" ref="SomeYDaoClassRef" />  </bean> 

Strictly speaking, the definition for b doesn't even require you to specify the class, you can leave that out:

<bean id="b" abstract="true">     <property name="daox" ref="SomeXDaoClassRef" />  </bean>  <bean id="a" parent="b" class="com.mypro.A">     <property name="daoy" ref="SomeYDaoClassRef" />  </bean> 

However, for clarity, and to give your tools a better chance of helping you out, it's often best to leave it in.

Section 3.7 of the Spring Manual discusses bean definition inheritance.