PowerMock的java.lang.VerifyError: Inconsistent stackmap frames at branch target异常分析

使用PowerMock进行单元测试时，要测试如下构造函数：

public FileSourceAeroflexPc(AeroflexPcResource resource){   ...}

执行测试的过程中，每次运行到这里就会抛出如下异常：

java.lang.VerifyError: Inconsistent stackmap frames at branch target 126Exception Details:  Location:    com/ericsson/commonlibrary/resourcemanager/file/FileSourceAeroflexPc.<init>(Lcom/ericsson/commonlibrary/resourcemanager/resourcedata/model/AeroflexPcResource;)V @126: aload_2  Reason:    Type uninitializedThis (current frame, locals[2]) is not assignable to 'com/ericsson/commonlibrary/resourcemanager/file/FileSourceAeroflexPc' (stack map, locals[2])  Current Frame:    bci: @112    flags: { flagThisUninit }    locals: { uninitializedThis, 'com/ericsson/commonlibrary/resourcemanager/resourcedata/model/AeroflexPcResource', uninitializedThis, 'java/lang/String', 'java/lang/String', 'java/lang/String', integer, 'java/lang/String', 'java/lang/String', 'java/lang/String', top, 'java/lang/Object' }    stack: { 'java/lang/Object', 'java/lang/Object' }  Stackmap Frame:    bci: @126    flags: { flagThisUninit }    locals: { uninitializedThis, 'com/ericsson/commonlibrary/resourcemanager/resourcedata/model/AeroflexPcResource', 'com/ericsson/commonlibrary/resourcemanager/file/FileSourceAeroflexPc', 'java/lang/String', 'java/lang/String', 'java/lang/String', integer, 'java/lang/String', 'java/lang/String', 'java/lang/String' }    stack: { }  Bytecode:    0000000: 2a2b b900 1701 0012 192b b900 1c01 0010    0000010: 152b b900 1f01 002b b900 2201 0012 243a    0000020: 093a 083a 0736 063a 053a 044e 4d12 26b8    0000030: 002c 1007 bd00 2e59 032d 5359 0419 0453    0000040: 5905 1905 5359 06bb 0030 5915 06b7 0033    0000050: 5359 0719 0753 5908 1908 5359 1006 1909    0000060: 5312 35b8 0039 b800 3f3a 0b19 0bb2 0043    0000070: a500 0e2a 01c0 0045 b700 49a7 0016 2c2d    0000080: 1904 1905 1506 1907 1908 1909 b700 4b01    0000090: 572a b700 4fb1                           Stackmap Table:    full_frame(@126,{UninitializedThis,Object[#15],Object[#16],Object[#18],Object[#18],Object[#18],Integer,Object[#18],Object[#18],Object[#18]},{})    full_frame(@145,{UninitializedThis,Object[#15]},{})at java.lang.Class.getDeclaredMethods0(Native Method)at java.lang.Class.privateGetDeclaredMethods(Class.java:2531)at java.lang.Class.getDeclaredMethod(Class.java:2002)at org.mockito.cglib.proxy.Enhancer.getCallbacksSetter(Enhancer.java:631)at org.mockito.cglib.proxy.Enhancer.isEnhanced(Enhancer.java:605)at org.powermock.api.extension.proxyframework.ProxyFrameworkImpl.isProxy(ProxyFrameworkImpl.java:50)at org.powermock.reflect.internal.WhiteboxImpl.getUnmockedType(WhiteboxImpl.java:1661)at org.powermock.api.mockito.internal.expectation.DefaultConstructorExpectationSetup.createNewSubstituteMock(DefaultConstructorExpectationSetup.java:92)at org.powermock.api.mockito.internal.expectation.DefaultConstructorExpectationSetup.withArguments(DefaultConstructorExpectationSetup.java:54)at com.ericsson.commonlibrary.resourcemanager.file.FileTransferServiceTest.setup(FileTransferServiceTest.java:62)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:606)at org.junit.internal.runners.MethodRoadie.runBefores(MethodRoadie.java:132)at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:95)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:86)at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:33)at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:45)at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:104)at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:53)at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

分析：

PowerMock中为支持对构造函数的测试，借助于Javassist实现对字节码的操作。但是从Java 6开始引入的Stack Map Frames特性与Javassist不兼容。在Java 6中该Stack Map Frames还是可选的。但是到了Java 7，该Stackmap Frames已经是默认使用的，所以不兼容问题导致了该异常。

解决：

解决方案有2个，一个是改变JVM的配置，一个是改变Javassist。Javassist目前的最新版本3.21.0-GA还不兼容该特性。

这里，我们为单元测试设置如下JVM 7参数，以禁用该Stack Map Frames特性。

-XX:-UseSplitVerifier

如果使用Maven的maven-surefire-plugin插件进行测试，还需要为该插件设置启动参数如下：

<pluginManagement>    <plugins>        <plugin>            <groupId>org.apache.maven.plugins</groupId>            <artifactId>maven-surefire-plugin</artifactId>            <version>2.19.1</version>            <configuration>                <argLine>-XX:-UseSplitVerifier</argLine>            </configuration>        </plugin>    </plugins></pluginManagement>

但是对于Java 8，由于上述JVM参数以及不存在，所以Stack Map Frames特性导致的字节码操作工具的兼容性问题无法避免。

参考文献：

http://blog.triona.de/development/jee/how-to-use-powermock-with-java-7.html

http://jboss-javassist.github.io/javassist/

http://chrononsystems.com/blog/java-7-design-flaw-leads-to-huge-backward-step-for-the-jvm