java.lang.ClassFormatError: Invalid method Code length while using PowerMock

Question

I am running JUnit case with PowerMock in jdk7 using the below libraries :

cglib-nodep-2.2.2.jar
javassist-3.19.0-GA.jar
junit-4.12.jar
mockito-all-1.10.19.jar
objenesis-2.1.jar
powermock-mockito-1.6.2-full.jar

Below is code snippet from my Unit Test in which I am using PowerMock

@RunWith(PowerMockRunner.class)
@PrepareForTest(ValidateBindingImpl.class)
public class ValidateBindingImplTest{

//more code follows
}

While executing this test case I am getting following error:

java.lang.ClassFormatError: Invalid method Code length 119842 in class file com/v1/ValidateBindingImpl
    at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:269)
at org.powermock.core.classloader.MockClassLoader.loadModifiedClass(MockClassLoader.java:180)
at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass(DeferSupportingClassLoader.java:68)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:249)
at sun.reflect.generics.factory.CoreReflectionFactory.makeNamedType(CoreReflectionFactory.java:95)
at sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:107)
at sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:31)
at sun.reflect.annotation.AnnotationParser.parseSig(AnnotationParser.java:370)
at sun.reflect.annotation.AnnotationParser.parseClassValue(AnnotationParser.java:351)
at sun.reflect.annotation.AnnotationParser.parseClassArray(AnnotationParser.java:653)
at sun.reflect.annotation.AnnotationParser.parseArray(AnnotationParser.java:460)
at sun.reflect.annotation.AnnotationParser.parseMemberValue(AnnotationParser.java:286)
at sun.reflect.annotation.AnnotationParser.parseAnnotation(AnnotationParser.java:222)
at sun.reflect.annotation.AnnotationParser.parseAnnotations2(AnnotationParser.java:69)
at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:52)
at java.lang.Class.initAnnotationsIfNecessary(Class.java:3079)
at java.lang.Class.getAnnotation(Class.java:3038)
at org.junit.internal.MethodSorter.getDeclaredMethods(MethodSorter.java:52)
at org.junit.internal.runners.TestClass.getAnnotatedMethods(TestClass.java:45)
at org.junit.internal.runners.MethodValidator.validateTestMethods(MethodValidator.java:71)
at org.junit.internal.runners.MethodValidator.validateStaticMethods(MethodValidator.java:44)
at org.junit.internal.runners.MethodValidator.validateMethodsForDefaultRunner(MethodValidator.java:50)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.validate(PowerMockJUnit44RunnerDelegateImpl.java:108)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.<init>(PowerMockJUnit44RunnerDelegateImpl.java:70)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl.<init>(PowerMockJUnit47RunnerDelegateImpl.java:42)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit49RunnerDelegateImpl.<init>(PowerMockJUnit49RunnerDelegateImpl.java:25)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:156)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:40)
at org.powermock.tests.utils.impl.AbstractTestSuiteChunkerImpl.createTestDelegators(AbstractTestSuiteChunkerImpl.java:244)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.<init>(JUnit4TestSuiteChunkerImpl.java:61)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.<init>(AbstractCommonPowerMockRunner.java:32)
at org.powermock.modules.junit4.PowerMockRunner.<init>(PowerMockRunner.java:34)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:29)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:21)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:26)
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:444)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

Found similar post discussed here and here based on which I tried adding -XX:-UseSplitVerifier in VM arguments but it didn't work.

Moreover I understand that the error seem to occur due to lengthy method in my class file but as its my organization code I wont be able modify/split the method as suggested in some posts online.

Answer 1

You faced with the following issue: JVM has limit on method size in bites, but during byte code transformation which is required to make possible mocking static, final size of the method could exceed this limit. In this case you see this error

java.lang.ClassFormatError: Invalid method Code length 119842 in class file

In next release will be include fix, which addressed this issue by replacing huge method via code which throws exception by default, but you still able to suppress such, method.

But, it's still will be only workaround for classes you cannot modified. Right way to fix the issue, it's to refactor your code to make method smaller. There are a lot of refactoring techniques to achieve this goal.

Answer 2

You will probably not like my answer, but the only reasonable answer is: stop using PowerMock.

If your production code is such that you need PowerMock in order write unit tests; then seriously: change your production code. If you need PowerMock, then your "code under test" is most likely: bad.

PowerMock (and all other mocking frameworks that rely on byte code manipulation) most often, cause more trouble than good. They cause issues like the one you got now; they very much limit your ability to use different JVMs or to run coverage tools.

This comes from a person who spent countless hours fixing "PowerMock" based unit tests; and who has written hundreds of unit tests over the last months only relying on EasyMock; and not once had the need to turn to PowerMock.

Answer 3

To use JVM option '-noverify': https://bugs.eclipse.org/bugs/show_bug.cgi?id=435446