我有一个非常简单的@SpringBootTest：
@RunWith(SpringRunner.class)
@SpringBootTest(classes = MyApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT, properties = {...})
public class MyApplicationTest {
@Test
public void anyTest() { ... }
}
在我们在文件中添加@EnableSchedulerLock（来自Shedlock）之前，它按预期工作MyApplication.java 。
因为，我们遇到了这个问题：
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.instantiateUsingFactoryMethod(ConstructorResolver.java:582)
... 46 common frames omitted
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:483)
当 Spring 尝试实例化它时，就会发生这种情况resourceHandlerMapping：
@Bean
public HandlerMapping resourceHandlerMapping() {
Assert.state(this.applicationContext != null, "No ApplicationContext set");
Assert.state(this.servletContext != null, "No ServletContext set");
...
这就像在调用(from )@Bean之前创建的。setServletContextWebMvcConfigurationSupport