当另一个BeanPostProcessor时，Spring bean java.lang.String设置为null，而不是提供的字符串

Question

I have the following bean definitions in the application context XML:

<bean id="helloWorld" class="com.packt.lifecycle.HelloWorld">
</bean>

<bean name="message" class="java.lang.String">
   <constructor-arg value="testing" />
</bean>

When I run the code:

AbstractApplicationContext  context = new ClassPathXmlApplicationContext("applicationContext.xml");
System.out.println(context.getBean("message"));

It displays fine, that is, "testing". BUT, when I make the helloWorld bean implement BeanPostProcessor then the value of message bean becomes null. Is this a bug?

Answer 1

Ok, found the problem. The 2 methods of the BeanPostProcessor must return the first argument. Instead I was returning null. I found the answer here: I am using bean post processor, and it is giving null pointer exception