两个 Spring JUnit 测试类：@TestPropertySource 值不同时的 InstanceAlreadyExistsException

Question

我有两个相同的测试类：ATest 和 BTest。只是名称不同。这是 ATest：

@RunWith(SpringRunner.class)
@EnableAutoConfiguration
@TestPropertySource(properties = {"myProperty=true"})
@ActiveProfiles("test")
public class ATest {
    @Test
    public void aTest() throws Exception {
        Assert.assertEquals("Hello", "Hello");
    }
}

我同时运行这两个类，它们都通过了。但是，如果我打开两者之一并将 myProperty 的值更改为 false（现在 testA 和 testB 的 myProperty 值相反），第二个测试将失败并显示以下堆栈跟踪：

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.junit.runners.Suite.runChild(Suite.java:128)
    at org.junit.runners.Suite.runChild(Suite.java:27)
    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$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [org.springframework.cloud.context.environment.EnvironmentManager@444720b7] with key 'environmentManager'; nested exception is javax.management.InstanceAlreadyExistsException: org.springframework.cloud.context.environment:name=environmentManager,type=EnvironmentManager
    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: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.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)
    ... 32 more
Caused by: javax.management.InstanceAlreadyExistsException: org.springframework.cloud.context.environment:name=environmentManager,type=EnvironmentManager
    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)
    ... 41 more

这完全没有意义。有谁能明白什么是错的？

Answer 1

正如@Ivan 在评论中所说，解决方案如下：

当您使用不同的属性运行测试时，Spring 会在同一个 JVM 中启动两个不同的上下文（每个属性集一个）。但是上下文在同一个 JMX 域名中，这是不可能的。这在此处进行了详细说明：While deploying more then one Spring boot application in a single tomcat server means showing exception. How to solve this?

此问题的解决方法是为每个测试类指定不同的 JMX 域名。例如，查看这个测试类的@TestPropertySource：

@RunWith(SpringRunner.class)
@EnableAutoConfiguration
@TestPropertySource(properties = {"mock.random-devices=false", "spring.application.name=BTest", "spring.jmx.default-domain=BTest"})
@ActiveProfiles("test")
public class BTest {
    @Test
    public void bTest() throws Exception {
        Assert.assertEquals("Hello", "Hello");
    }
}

当然在ATest类中，app和JMX域名都是ATest。

这使得两个测试都成功。

感谢@Ivan 的帮助。