java - Spring MVC @EnableWebMvc Bean 配置

Question

我正在尝试使用 @Bean 注释配置要在 Spring MVC Controller 应用程序中使用的 Bean。

据我所知，@Bean注解相当于XML配置中的标签。我正在做的事情如下:

具有配置的类

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

但是当尝试在 MVC Controller 中 Autowiring myBean 时，它会失败。

bean 注入(inject)

@Controller
public class HomeController {

    @Autowired
    private MyBean myBean;

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

错误是:

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

最终评论

1. 还有其他通过注释 (@Bean) 配置的 Bean，可以毫无问题地注入(inject)。
2. MyBean 类没有实现或扩展任何内容。
3. 配置位置在 web.xml 中声明

session :

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

ContextConfig 类位于该包中

知道为什么会发生这种情况吗？

Answer 1

该异常与 MyBean 类无关。异常(exception)情况是:

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

Spring 无法将 javax.validation.ValidatorFactory 注入(inject) HomeController 类。检查 ValidatorFactory 类的配置。