在IBM JRE上运行jMockit测试时AttachNotSupportedException

Question

当我尝试使用IBM JDK运行简单的jMockit/JUnit测试时,我得到以下异常.有人遇到过这个问题吗？我试过-Dcom.ibm.tools.attach.enable=yes作为VM参数,但没有运气.相同的代码在Sun JDK中正常工作.

java.lang.RuntimeException: com.sun.tools.attach.AttachNotSupportedException: Unable to enqueue operation: the target VM does not support attach mechanism
    at mockit.internal.startup.JDK6AgentLoader.getVirtualMachineImplementationFromEmbeddedOnes(JDK6AgentLoader.java:89)
    at mockit.internal.startup.JDK6AgentLoader.loadAgent(JDK6AgentLoader.java:54)
    at mockit.internal.startup.AgentInitialization.initializeAccordingToJDKVersion(AgentInitialization.java:21)
    at mockit.internal.startup.Startup.initializeIfNeeded(Startup.java:98)
    at mockit.internal.startup.Startup.initializeIfPossible(Startup.java:112)
    at org.junit.runner.Runner.<clinit>(Runner.java:22)
    at java.lang.J9VMInternals.initializeImpl(Native Method)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:200)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:167)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:167)
    at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:13)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
    at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
    at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:24)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.<init>(JUnit4TestReference.java:33)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestClassReference.<init>(JUnit4TestClassReference.java:25)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:48)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: com.sun.tools.attach.AttachNotSupportedException: Unable to enqueue operation: the target VM does not support attach mechanism
    at sun.tools.attach.WindowsVirtualMachine.<init>(WindowsVirtualMachine.java:64)
    at mockit.internal.startup.JDK6AgentLoader.getVirtualMachineImplementationFromEmbeddedOnes(JDK6AgentLoader.java:73)
    ... 22 more
java.lang.NoClassDefFoundError: org.junit.internal.runners.ErrorReportingRunner (initialization failure)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:140)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:24)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.<init>(JUnit4TestReference.java:33)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestClassReference.<init>(JUnit4TestClassReference.java:25)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:48)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.NoClassDefFoundError: org.junit.runner.Runner (initialization failure)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:140)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:167)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
    ... 9 more
Caused by: java.lang.RuntimeException: com.sun.tools.attach.AttachNotSupportedException: Unable to enqueue operation: the target VM does not support attach mechanism
    at mockit.internal.startup.JDK6AgentLoader.getVirtualMachineImplementationFromEmbeddedOnes(JDK6AgentLoader.java:89)
    at mockit.internal.startup.JDK6AgentLoader.loadAgent(JDK6AgentLoader.java:54)
    at mockit.internal.startup.AgentInitialization.initializeAccordingToJDKVersion(AgentInitialization.java:21)
    at mockit.internal.startup.Startup.initializeIfNeeded(Startup.java:98)
    at mockit.internal.startup.Startup.initializeIfPossible(Startup.java:112)
    at org.junit.runner.Runner.<clinit>(Runner.java:22)
    at java.lang.J9VMInternals.initializeImpl(Native Method)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:200)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:167)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:167)
    at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:13)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
    ... 11 more
Caused by: com.sun.tools.attach.AttachNotSupportedException: Unable to enqueue operation: the target VM does not support attach mechanism
    at sun.tools.attach.WindowsVirtualMachine.<init>(WindowsVirtualMachine.java:64)
    at mockit.internal.startup.JDK6AgentLoader.getVirtualMachineImplementationFromEmbeddedOnes(JDK6AgentLoader.java:73)
    ... 22 more

我尝试-javaagent:jmockit.jar按照Kevin Welker的建议给出VM参数,我得到了以下异常.

Exception in thread "main" java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:600)
    at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:335)
    at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:350)
Caused by: java.lang.NullPointerException
    at mockit.internal.annotations.MockClassSetup.validateRealClass(MockClassSetup.java:59)
    at mockit.internal.annotations.MockClassSetup.<init>(MockClassSetup.java:38)
    at mockit.internal.annotations.MockClassSetup.<init>(MockClassSetup.java:77)
    at mockit.internal.annotations.MockClassSetup.<init>(MockClassSetup.java:99)
    at mockit.internal.startup.JMockitInitialization.setUpInternalStartupMock(JMockitInitialization.java:56)
    at mockit.internal.startup.JMockitInitialization.initialize(JMockitInitialization.java:29)
    at mockit.internal.startup.Startup.initialize(Startup.java:68)
    at mockit.internal.startup.Startup.premain(Startup.java:56)
    ... 6 more

Fatal error: processing of -javaagent failed

Answer 1

Attach API在IBM JDK 6.0中不起作用,至少在Windows上是这样.因此,有必要使用该-javaagent:jmockit.jar参数.

所述NullPointerException发生在MockClassSetup.java:59,使用时-javaagent,通过在IBM JDK的错误引起的.当注释属性中引用的类型(@MockClass在本例中)在类路径中不存在时,JDK应该抛出一个TypeNotPresentException.Oracle JDK按预期执行此操作,但IBM JDK会返回null属性值.

我刚刚在课堂上实现了一个解决方法MockClassSetup,它将在9月底的下一个JMockit版本中提供.现在,您可以通过将TestNG添加到类路径来避免此问题(因为"未找到类型"是org.testng.TestNG类).