如何初始化spring-boot WebMvc？ （ServletContext始終爲空）

Question

我正在使用spring-boot-starter-web將嵌入式Web服務器添加到現有應用程序。

問題：在啓動過程中servletContext始終爲null。

我正在使用ConfigurableApplicationContext ctx = SpringApplication.run(Config.class);

我的應用程序如果我排除WebMvcAutoConfiguration的CTX的工作原理如下：

@Configuration 
@EnableAutoConfiguration(exclude = {WebMvcAutoConfiguration.class}) 
public class Config implements ServletContextInitializer { 
     @Override 
     public void onStartup(ServletContext servletContext) throws ServletException { 
      servletContext.getSessionCookieConfig().setName("yourCookieName"); 
     } 
} 

但正如我需要自動配置，我刪除了排除。在這種情況下，由於servletContext爲空，因此在啓動期間會引發以下錯誤。

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultServletHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method 'defaultServletHandlerMapping' threw exception; nested exception is java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling 
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1119) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1014) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) 
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) 
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755) 
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757) 
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480) 
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:957) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:946) 
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method 'defaultServletHandlerMapping' threw exception; nested exception is java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling 
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) 
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) 
    ... 17 more 
Caused by: java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling 
    at org.springframework.util.Assert.notNull(Assert.java:112) 
    at org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer.<init>(DefaultServletHandlerConfigurer.java:53) 
    at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.defaultServletHandlerMapping(WebMvcConfigurationSupport.java:426) 
    at org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$EnableWebMvcConfiguration$$EnhancerBySpringCGLIB$$f3d6343f.CGLIB$defaultServletHandlerMapping$34(<generated>) 
    at org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$EnableWebMvcConfiguration$$EnhancerBySpringCGLIB$$f3d6343f$$FastClassBySpringCGLIB$$ee873d68.invoke(<generated>) 
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) 
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:309) 
    at org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$EnableWebMvcConfiguration$$EnhancerBySpringCGLIB$$f3d6343f.defaultServletHandlerMapping(<generated>) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:483) 
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) 
    ... 18 more 

Answer 1

解決方案：我曾在application.properties聲明：

spring.main.web_environment =假

當然，同時這種說法存在webmvc無法初始化中。