RequiredAnnotationBeanPostProcessor should not kick in for factory-bean definitions [SPR-10458]

[spring-projects-issues]

Andreas Hubold opened SPR-10458 and commented

The RequiredAnnotationBeanPostProcessor throws an exception that properties of a bean have not been configured if the bean was returned from a factory bean and has setters annotated with @Required.

For example with the following XML context definition:

  <context:annotation-config/>

  <bean id="test" class="Test">
    <property name="config" value="value"/>
  </bean>

  <bean id="testBuilder" class="TestBuilder">
    <property name="test" ref="test"/>
  </bean>

  <bean id="test2" factory-bean="testBuilder" factory-method="getTest"/>

Method Test#setConfig is annotated with @Required.
TestBuilder#getTest is just implemented to return the Test instance that was set with #setTest.

(I know the example does not make any sense but that's just to demonstrate the case in a simple form).

When starting the application context I get the following exception:

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'test2' defined in class path resource [test.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanInitializationException: Property 'config' is required for bean 'test2'
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:609)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:469)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at TestSpringRequired.main(TestSpringRequired.java:10)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: org.springframework.beans.factory.BeanInitializationException: Property 'config' is required for bean 'test2'
	at org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor.postProcessPropertyValues(RequiredAnnotationBeanPostProcessor.java:149)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
	... 16 more

---

Affects: 3.1.2

1 votes, 5 watchers

[spring-projects-issues]

Jacek Psiuk commented

Encountered the same problem for version 3.2.1.RELEASE

[spring-projects-issues]

Tatiana Anoshko commented

The same occurs with 3.0.5.RELEASE

[spring-projects-issues]

Juergen Hoeller commented

It was never particularly well-defined whether RequiredAnnotationBeanPostProcessor would kick in for factory method definitions... Historically it did, and the solution if you had a problem with it was simply to omit the @Required annotations in such a scenario.

However, you do have a point that factory-bean definitions are likely to return fully completed bean instances, similar to @Bean methods. So as of Spring 4.0, RequiredAnnotationBeanPostProcessor skips bean definitions with factory-bean references. However, it still kicks in for static factory-method declarations which are typically simply used as a constructor alternative.

Juergen