由于继承WebMvcConfigurationSupport使自动化配置失效BeanCreationException、BeanInstantiationException

在使用SpringBoot 2.3.3的时候，使用配置类来修改默认的端口号。
在低版本可以继承 WebMvcConfigurerAdapter 修改，但由于已经过期。所以我采用了它的扩展类 WebMvcConfigurationSupport。但是由于 WebMvcConfigurationSupport 会使得自动话配置失效。故这里可以实现 WebMvcConfigurer

修改后的写法

@Configuration
public class MyMvcConfig implements WebMvcConfigurer {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        //浏览器发送/hx请求，请求到hi.html页面
        registry.addViewController("/hx").setViewName("hi");
        registry.addViewController("/").setViewName("index");
        registry.addViewController("/index.html").setViewName("index");
    }
}

错误示例：

public class MyMvcConfig extends WebMvcConfigurationSupport {

//  Spring Boot2.0以上版本EmbeddedServletContainerCustomizer被WebServerFactoryCustomizer替代
    @Bean
    public WebServerFactoryCustomizer<ConfigurableWebServerFactory> webServerFactoryCustomizer(){
        return new WebServerFactoryCustomizer<ConfigurableWebServerFactory>() {
            @Override
            public void customize(ConfigurableWebServerFactory factory) {
                factory.setPort(8081);
            }
        };
    }
}

附：错误日志

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'resourceHandlerMapping' defined in class path resource [com/hx/config/MyMvcConfig.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:655) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:635) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1176) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:897) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) [spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) [spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) [spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.3.3.RELEASE.jar:2.3.3.RELEASE]
	at com.hx.CrudApplication.main(CrudApplication.java:10) [classes/:na]
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) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:650) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	... 20 common frames omitted
Caused by: java.lang.IllegalStateException: No ServletContext set
	at org.springframework.util.Assert.state(Assert.java:76) ~[spring-core-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.resourceHandlerMapping(WebMvcConfigurationSupport.java:534) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at com.hx.config.MyMvcConfig$$EnhancerBySpringCGLIB$$f2efaeba.CGLIB$resourceHandlerMapping$30(<generated>) ~[classes/:na]
	at com.hx.config.MyMvcConfig$$EnhancerBySpringCGLIB$$f2efaeba$$FastClassBySpringCGLIB$$9e5ca254.invoke(<generated>) ~[classes/:na]
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at com.hx.config.MyMvcConfig$$EnhancerBySpringCGLIB$$f2efaeba.resourceHandlerMapping(<generated>) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_162]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_162]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_162]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	... 21 common frames omitted