问题描述
当我尝试使用IBM JDK运行简单的jMockit/JUnit测试时，出现以下异常.有人遇到过这个问题吗?我尝试给定-Dcom.ibm.tools.attach.enable=yes作为VM参数，但是没有运气.相同的代码在Sun JDK中可以正常工作.
I am getting the below exception when I try to run a simple jMockit/JUnit test using IBM JDK. Has anyone faced this issue? I tried given -Dcom.ibm.tools.attach.enable=yes as VM argument but no luck. The same code is working fine in Sun JDK.
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
我尝试按照Kevin Welker的建议为VM参数提供-javaagent:jmockit.jar，但出现了以下异常.
I tried giving the VM argument -javaagent:jmockit.jar as suggested by Kevin Welker and I got the below exception.
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
推荐答案
Attach API根本无法在IBM JDK 6.0中运行，至少在Windows上如此.因此，有必要使用-javaagent:jmockit.jar参数.
The Attach API simply doesn't work in the IBM JDK 6.0, at least on Windows. Therefore, it's necessary to use the -javaagent:jmockit.jar parameter.
使用-javaagent时在MockClassSetup.java:59处出现的NullPointerException是由IBM JDK中的错误引起的.如果在类路径中不存在注释属性中引用的类型(在本例中为@MockClass)，则JDK应该抛出TypeNotPresentException. Oracle JDK按照预期方式进行操作，但是IBM JDK返回null来代替属性值.
The NullPointerException that occurs at MockClassSetup.java:59, when using -javaagent, is caused by a bug in the IBM JDK. When a type referenced in an annotation attribute (@MockClass, in this case) is not present in the classpath, the JDK should throw a TypeNotPresentException. The Oracle JDKs do so as expected, but the IBM JDK returns null instead for the attribute value.
我刚刚在类MockClassSetup中实现了解决方法，该方法将在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该问题(因为找不到类型"是org.testng.TestNG类).
I just implemented a workaround for this in class MockClassSetup, which will be available in the next JMockit release, by the end of september. For now, you can avoid the problem by adding TestNG to the classpath (since the "type not found" is the org.testng.TestNG class).
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