Unit testing - Failed to load ApplicationContext

Question

I have a simple TestNG (Same result with JUnit) @Test under class as below

@ContextConfiguration(classes = { Config.class })
@ActiveProfiles({ "dev" })
public class TestDAO extends AbstractTestNGSpringContextTests {

It started failing after merging several code branches.

The error is general/with unspecified origin

[main] ERROR org.springframework.test.context.TestContextManager - Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@33065d67] to prepare test instance [com.TestDAO]
java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)
    at org.springframework.test.context.testng.AbstractTestNGSpringContextTests.springTestContextPrepareTestInstance(AbstractTestNGSpringContextTests.java:149)
    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:498)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:104)
    at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:515)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:217)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:144)
    at org.testng.internal.TestMethodWorker.invokeBeforeClassMethods(TestMethodWorker.java:169)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
    at org.testng.TestRunner.privateRun(TestRunner.java:756)
    at org.testng.TestRunner.run(TestRunner.java:610)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:387)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:382)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
    at org.testng.SuiteRunner.run(SuiteRunner.java:289)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1293)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1218)
    at org.testng.TestNG.runSuites(TestNG.java:1133)
    at org.testng.TestNG.run(TestNG.java:1104)
    at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:236)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:81)
Caused by: 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.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:128)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60)
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:108)
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:251)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)
    ... 30 more
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:189)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
    ... 47 more
Caused by: java.lang.IllegalStateException: No ServletContext set
    at org.springframework.util.Assert.state(Assert.java:70)
    at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.resourceHandlerMapping(WebMvcConfigurationSupport.java:450)
    at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration$$EnhancerBySpringCGLIB$$825de2bf.CGLIB$resourceHandlerMapping$31(<generated>)
    at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration$$EnhancerBySpringCGLIB$$825de2bf$$FastClassBySpringCGLIB$$14c639e2.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358)
    at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration$$EnhancerBySpringCGLIB$$825de2bf.resourceHandlerMapping(<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:498)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)

It seems that the context is loaded twice, where should I found the issue?

It's not related to OAuth2SecurityConfiguration as other answer refer to

OAuth2SecurityConfiguration bean isn't automatically created by boot and neither it is mandatory for MethodSecurityConfigurer

And not related to RoleHierarchy

Comment out “expressionHandler.setRoleHierarchy(roleHierarchy);”, exception disappear.

Answer 1

If the spring context includes web related configuration, you need to put @WebAppConfiguration above your test case. Additionally, it seems you need @RunWith(SpringJUnit4ClassRunner.class) in the case of JUnit runner. So I would change your code as this:

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(classes = { Config.class })
@ActiveProfiles({ "dev" })
public class TestDAO extends AbstractTestNGSpringContextTests {