Spring MVC @EnableWebMvc Bean配置

Question

I´m trying to configure a Bean to be used in a Spring MVC Controller app using the @Bean annotation.

As far as I know, the @Bean annotation is equivalent to the tag in XML configuration. What I am doing is the following:

The class with the configuration

@Configuration
public class ContextConfig {
    @Bean
    public MyBean myBean() {
        return new MyBean();
    }
}

But when trying to autowire myBean in an MVC Controller it fails.

The bean injection

@Controller
public class HomeController {

    @Autowired
    private MyBean myBean;

    @RequestMapping({"/", "/home"})
    public ModelAndView home (ModelAndView model) {
        model.setViewName("home");
        return model;
    }
}

The error is:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private javax.validation.ValidatorFactory com.proeza.sgs.controller.HomeController.factory; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.ValidatorFactory] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private javax.validation.ValidatorFactory com.proeza.sgs.controller.HomeController.factory; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.ValidatorFactory] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    ... 22 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.ValidatorFactory] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1100)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:855)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
    ... 24 more

Final comments

1. There are other beans configured via annotation (@Bean), that are being injected without problem.
2. The MyBean class is not implementing nor extending anything.
3. The configuration location is declared in the web.xml

Conf:

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>com.myapp.config</param-value>
</context-param>

The ContextConfig class is in that package

Any idea why is this happening?

Answer 1

The exception is not related to the MyBean class. The exception says:

No qualifying bean of type [javax.validation.ValidatorFactory] found for dependency

Spring failed to inject javax.validation.ValidatorFactory to the HomeController class. Check that configuration for ValidatorFactory class.

Answer 2

Thanks for the response Ilya. You´re right, the stack I pasted was not the correct one. The cause was that to simplify, I gave the example with MyBean and I forgot to rename it in the stack.

The problem has been solved. The real name of MyBean is MessageResolver and what was happening was that I already had another method called messageResolver inside the ContextConfig class, used to create a bean for Thymeleaf. The difference is that mine does not receive parameters and the other receives a MessageSource, BUT...Reading the Spring docmentation I found this:

Spring Doc Quote:

2.2.6. Customizing bean naming

By default, JavaConfig uses a @Bean method's name as the name of the resulting bean. This functionality can be overridden, however, using the BeanNamingStrategy extension point.

Spring @Bean doc

So, the problem is that the bean was not being created because it was being overrided its definition. The error disappears just renaming the messageResolver method.

Thanks again. Regards!