为了解决这个问题，我遇到了很多问题。我只是想运行一组基本的测试，并使用JMockit生成一份覆盖率报告。这是针对一堂课，目的是确保我们可以运行它，所以我什至没有写测试，教授做到了。在让JMockit完全工作之后出现了很多问题之后，我现在通过了测试（使用了模拟），但是如果我使用JMockit 1.43，则不会生成覆盖率报告。如果我使用1.38，则所有测试均失败，但是我确实获得了覆盖率报告。我同时使用了JDK 8和JDK 11，似乎没有给我任何不同的错误。我没有使用Maven。根据教授的要求，我正在使用Eclipse。测试是用JUnit 5编写的。
这是我的VM参数（用于1.38，但我唯一要更改的是1.43）：
-javaagent:/path/to/jmockit-1.38.jar
-Djmockit-coverage-output=html
-Djmockit-coverage-metrics=line,path
-Dlog4j.configurationFile=./conf/log4j-file-config.xml
-Djmockit-coverage-excludes=sun.jvmstat.*
同样，没有遇到1.43的错误（只是没有生成覆盖报告），但这是我使用1.38时遇到的错误：
java.lang.UnsupportedOperationException: class redefinition failed: attempted to change the class NestHost or NestMembers attribute
at java.instrument/sun.instrument.InstrumentationImpl.redefineClasses0(Native Method)
at java.instrument/sun.instrument.InstrumentationImpl.redefineClasses(InstrumentationImpl.java:193)
at mockit.internal.startup.Startup.redefineMethods(Startup.java:171)
at mockit.internal.state.MockFixture.redefineClasses(MockFixture.java:165)
at mockit.internal.expectations.mocking.BaseTypeRedefinition.applyClassRedefinition(BaseTypeRedefinition.java:238)
at mockit.internal.expectations.mocking.BaseTypeRedefinition.redefineClass(BaseTypeRedefinition.java:231)
at mockit.internal.expectations.mocking.BaseTypeRedefinition.redefineClassAndItsSuperClasses(BaseTypeRedefinition.java:202)
at mockit.internal.expectations.mocking.BaseTypeRedefinition.redefineMethodsAndConstructorsInTargetType(BaseTypeRedefinition.java:188)
at mockit.internal.expectations.mocking.BaseTypeRedefinition.redefineTargetClassAndCreateInstanceFactory(BaseTypeRedefinition.java:271)
at mockit.internal.expectations.mocking.BaseTypeRedefinition.redefineType(BaseTypeRedefinition.java:70)
at mockit.internal.expectations.mocking.TypeRedefinition.redefineType(TypeRedefinition.java:29)
at mockit.internal.expectations.mocking.FieldTypeRedefinitions.redefineFieldType(FieldTypeRedefinitions.java:82)
at mockit.internal.expectations.mocking.FieldTypeRedefinitions.redefineFieldType(FieldTypeRedefinitions.java:68)
at mockit.internal.expectations.mocking.FieldTypeRedefinitions.redefineFieldTypes(FieldTypeRedefinitions.java:55)
at mockit.internal.expectations.mocking.FieldTypeRedefinitions.(FieldTypeRedefinitions.java:34)
at mockit.integration.internal.TestRunnerDecorator.handleMockFieldsForWholeTestClass(TestRunnerDecorator.java:153)
at mockit.integration.junit5.JMockitExtension.postProcessTestInstance(JMockitExtension.java:55)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$invokeTestInstancePostProcessors$3(ClassTestDescriptor.java:215)
at org.junit.jupiter.engine.descriptor.JupiterTestDescriptor.executeAndMaskThrowable(JupiterTestDescriptor.java:141)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$invokeTestInstancePostProcessors$4(ClassTestDescriptor.java:215)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1654)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:312)
at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734)
at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734)
at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.invokeTestInstancePostProcessors(ClassTestDescriptor.java:214)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.instantiateAndPostProcessTestInstance(ClassTestDescriptor.java:196)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$testInstanceProvider$0(ClassTestDescriptor.java:185)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$testInstanceProvider$1(ClassTestDescriptor.java:189)
at java.base/java.util.Optional.orElseGet(Optional.java:369)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$testInstanceProvider$2(ClassTestDescriptor.java:188)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:81)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:58)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.prepare(HierarchicalTestExecutor.java:89)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:74)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:55)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
答案 0 :(得分：0)
切换到Java 9（即使不受支持，教授正在使用的东西），jmockit-1.38和这些VM参数，并且可以使用：
-Djdk.attach.allowAttachSelf
-Djmockit-coverage-metrics=line,path
-Djmockit-coverage-output=html
-Djmockit-coverage-srcDirs=src/main/java
-Dlog4j.configurationFile=./conf/log4j-file-config.xml
-Djmockit-coverage-excludes=sun.jvmstat.*
仍然不确定如何使用8或11（以及jmockit版本）使其工作。