BeanNotOfRequiredTypeException if @Bean factory method returns null #34543
Description
I've upgraded our app from spring 3.3.5 to 3.4.3 and on the newer version the app is throwing the following error on initialization:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.actuate.autoconfigure.metrics.task.TaskExecutorMetricsAutoConfiguration': Injection of autowired dependencies failed at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:515) ~[spring-beans-6.2.3.jar:6.2.3] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1445) ~[spring-beans-6.2.3.jar:6.2.3] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:600) ~[spring-beans-6.2.3.jar:6.2.3] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:523) ~[spring-beans-6.2.3.jar:6.2.3] ... many more Caused by: org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'splitFilesTaskExecutor' is expected to be of type 'org.springframework.core.task.TaskExecutor' but was actually of type 'org.springframework.beans.factory.support.NullBean' at org.springframework.beans.factory.support.AbstractBeanFactory.adaptBeanInstance(AbstractBeanFactory.java:424) ~[spring-beans-6.2.3.jar:6.2.3] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:405) ~[spring-beans-6.2.3.jar:6.2.3] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207) ~[spring-beans-6.2.3.jar:6.2.3] ... many more This spring bean is created the following way:
@Configuration public class ProjectLauncherConfiguration { @Bean() public TaskExecutor splitFilesTaskExecutor() { if ( ** some logic ** ) { ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor(); executor.setMaxPoolSize(splitMaxPoolSize); executor.setCorePoolSize(splitPoolSize); executor.setQueueCapacity(Integer.MAX_VALUE); return executor; } return null; } }If the bean is created, it works just fine. But when the scenario doesn't create the bean, the exception is thrown and the app is does not initialize.