Java 创建名为'；resourceHandlerMapping'；

我有一个使用spring的应用程序，它使用一个JPA配置类来处理我的数据库，使用一个WebAppMVCConfiguer类通过json消息来处理前端。两者都有一个@配置，并且在同一个包中。我在根包中有一个App类，其中包含@Configuration和@ComponentScan以及我的main方法

当我启动App类时，出现以下错误：

    Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'resourceHandlerMapping' defined in class path resource [org/springframework/web/servlet/config/annotation/DelegatingWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method 'resourceHandlerMapping' threw exception; nested exception is java.lang.IllegalStateException: No ServletContext set
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:656)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:636)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
    at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:89)
    at com.bnpp.creditauto.App.main(App.java:22)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method 'resourceHandlerMapping' threw exception; nested exception is java.lang.IllegalStateException: No ServletContext set
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651)
    ... 14 more
Caused by: java.lang.IllegalStateException: No ServletContext set
    at org.springframework.util.Assert.state(Assert.java:73)
    at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.resourceHandlerMapping(WebMvcConfigurationSupport.java:533)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 15 more

JPA配置类：

package com.bnpp.creditauto.config;

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class JpaConfiguration {
  ...
}

WebAppMVCConfiguer类：

package com.bnpp.creditauto.config;

@Configuration
@EnableWebMvc
public class WebAppMvcConfigurer implements WebMvcConfigurer {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**").addResourceLocations("/css/");
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }
}

---

所以我找到了答案，当您在

webmvcconfiguer

类中有

@Configuration

并且在处理Jpa配置的类中有

@Configuration

时，您无法使用spring上下文启动main方法。

---

如果删除任何一个配置，您可以使用main方法，但是没有

@Configuration

的类将停止工作。创建一个初始化或测试的方法，并在浏览器或处理前端的应用程序中使用HTTP请求调用它，它将正常工作。

如果有人仍然找不到问题，则考虑添加另一个方案。因此，对于注释“@SpringBootApplication”，spring负责处理大多数子注释，如“@ComponentScan”。假设您有一个测试配置类，并且您提供了自己的组件扫描包，那么默认的应用程序级上下文加载就不会发生。因此，在这种情况下，您只想坚持使用其他配置，例如使用数据源（mem-dbs）注入您自己的属性文件。

您能解释得更清楚一点吗。。。也许使用一个示例[]已经很长时间了，我不再使用spring编写代码了。我有三个类在这里进行配置，希望能有所帮助。显然，我创建了一个WebAppInitializer，它扩展了WebApplicationInitialized，请检查file.tnx中的代码，我将检查它

package com.bnpp.creditauto.config;

@Configuration
@EnableWebMvc
public class WebAppMvcConfigurer implements WebMvcConfigurer {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**").addResourceLocations("/css/");
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }
}