Spring Integration DSL Unit test cases failure on running all from build script - spring-integration

Question

I have some unit test cases written for spring integration flows. On running the individual test cases from IDE no issues, but on running all test cases from gradle build some test cases are failing.
I found a QC on related issue:
https://jira.spring.io/browse/XD-3709
If any one knows solution for this, please post.
Unit Tests with below annotations:
#RunWith(SpringRunner.class)
#Import(AlarmAPIApplication.class)
#PropertySource("classpath:application.properties ")
#FixMethodOrder
public class HostRegistrationFlowTest {
#Value("${em.host.registration.url}")
String hostRegistrationUrl;
#Autowired
RestTemplate restTemplate;
#Autowired
SubscribableChannel registerHostInputChannel;
#Test
public void testRegisterHost() {
Error on running from gradle script:
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.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.runTestClass(JUnitTestClassExecuter.java:86)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.execute(JUnitTestClassExecuter.java:49)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassProcessor.processTestClass(JUnitTestClassProcessor.java:69)
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:48)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.messaging.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32)
at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:105)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.messaging.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:355)
at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [org.springframework.integration.router.MethodInvokingRouter#0] with key 'org.springframework.integration.router.MethodInvokingRouter#0'; nested exception is javax.management.InstanceAlreadyExistsException: org.springframework.integration.router:name=org.springframework.integration.router.MethodInvokingRouter#0,type=MethodInvokingRouter
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:628)
at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:550)
at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:432)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:781)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
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:259)
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)
... 44 more
Caused by: javax.management.InstanceAlreadyExistsException: org.springframework.integration.router:name=org.springframework.integration.router.MethodInvokingRouter#0,type=MethodInvokingRouter
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
at org.springframework.jmx.support.MBeanRegistrationSupport.doRegister(MBeanRegistrationSupport.java:195)
at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:682)
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:618)
... 55 more

Answer 1

javax.management.InstanceAlreadyExistsException: org.springframework.integration.router:name=org.springframework.integration.router.MethodInvokingRouter#0,type=MethodInvokingRouter
You have to use #DirtiesContext on the test class level to close all the application contexts after performing their tests. Otherwise the application contexts, created during test class initialization, aren't closed to chase the caching goal in between different test classes.
In your case one of the test classes initialize application context and register MBeans into the JMX. But not closing the application context cause the next one to try to register the MBean again. Just because you use some common configuration for different test classes.