如何从静态内部类构造函数创建Spring bean？

Question

I am trying to use the Spring Framework IoC Container to create an instance of class ThreadPoolExecutor.CallerRunsPolicy . In Java, I'd do it this way...

import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadPoolExecutor;
...
RejectedExecutionHandler rejectedExecutionHandler = new ThreadPoolExecutor.CallerRunsPolicy();

But when I try to do the equivalent in Spring, it throws a CannotLoadBeanClassException .

<beans>
   <bean class="java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy"/>
</beans>

More generally: in a Spring ApplicationContext XML, how can you call a constructor of a static inner class?

Answer 1

I think the reason it is not working is because Spring is not able to understand it as a static inner class. Probably this can work:

<beans>
   <bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy"/>
</beans>

Answer 2

Use the factory-method attribute :

The following bean definition specifies that the bean will be created by calling a factory-method. The definition does not specify the type (class) of the returned object, only the class containing the factory method. In this example, the createInstance() method must be a static method.

 <bean id="clientService" class="examples.ClientService" factory-method="createInstance"/>