Powermock - java.lang.IllegalStateException: Failed to transform class

Question

Description:

I am trying to test a static method from a class. I am using powerMock (1.6.2) + mockito (1.10.19) for mocking along with Junit4 (4.12) & java8.

Issue:

Getting the error: "Failed to transform class with name com.gs.ops.domain.StaticClass Reason: java.io.IOException: invalid constant type: 18"

Solutions Tried:

1. Googled threads for issue on with powermock - mockito & java-8

2. Excluded java assist from powermock and added java assist 3.19.0-GA

3. Tried different versions of powermock (1.5.4, 1.6.2...)

Below is the exception stack trace:

 java.lang.IllegalStateException: Failed to transform class with name com.StaticClass. Reason: java.io.IOException: invalid constant type: 18
        at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:266)
        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:357)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:340)
        at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:145)
        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:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
        at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)
        at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
        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:33)
        at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
    Caused by: java.lang.RuntimeException: java.io.IOException: invalid constant type: 18
        at javassist.CtClassType.getClassFile2(CtClassType.java:203)
        at javassist.compiler.MemberResolver.lookupMethod(MemberResolver.java:110)
        at javassist.compiler.MemberResolver.lookupMethod(MemberResolver.java:96)
        at javassist.compiler.TypeChecker.atMethodCallCore(TypeChecker.java:704)
        at javassist.expr.NewExpr$ProceedForNew.setReturnType(NewExpr.java:243)
        at javassist.compiler.JvstTypeChecker.atCallExpr(JvstTypeChecker.java:146)
        at javassist.compiler.ast.CallExpr.accept(CallExpr.java:45)
        at javassist.compiler.TypeChecker.atVariableAssign(TypeChecker.java:248)
        at javassist.compiler.TypeChecker.atAssignExpr(TypeChecker.java:217)
        at javassist.compiler.ast.AssignExpr.accept(AssignExpr.java:38)
        at javassist.compiler.CodeGen.doTypeCheck(CodeGen.java:241)
        at javassist.compiler.CodeGen.atStmnt(CodeGen.java:329)
        at javassist.compiler.ast.Stmnt.accept(Stmnt.java:49)
        at javassist.compiler.CodeGen.atStmnt(CodeGen.java:350)
        at javassist.compiler.ast.Stmnt.accept(Stmnt.java:49)
        at javassist.compiler.CodeGen.atIfStmnt(CodeGen.java:404)
        at javassist.compiler.CodeGen.atStmnt(CodeGen.java:354)
        at javassist.compiler.ast.Stmnt.accept(Stmnt.java:49)
        at javassist.compiler.Javac.compileStmnt(Javac.java:568)
        at javassist.expr.NewExpr.replace(NewExpr.java:206)
        at org.powermock.core.transformers.impl.MainMockTransformer$PowerMockExpressionEditor.edit(MainMockTransformer.java:418)
        at javassist.expr.ExprEditor.loopBody(ExprEditor.java:211)
        at javassist.expr.ExprEditor.doit(ExprEditor.java:90)
        at javassist.CtClassType.instrument(CtClassType.java:1374)
        at org.powermock.core.transformers.impl.MainMockTransformer.transform(MainMockTransformer.java:74)
        at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:251)
        ... 24 more
    Caused by: java.io.IOException: invalid constant type: 18
        at javassist.bytecode.ConstPool.readOne(ConstPool.java:1090)
        at javassist.bytecode.ConstPool.read(ConstPool.java:1033)
        at javassist.bytecode.ConstPool.<init>(ConstPool.java:149)
        at javassist.bytecode.ClassFile.read(ClassFile.java:737)
        at javassist.bytecode.ClassFile.<init>(ClassFile.java:108)
        at javassist.CtClassType.getClassFile2(CtClassType.java:190)
        ... 49 more

Pom file:

<dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-api-mockito</artifactId>
            <version>1.6.2</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-module-junit4</artifactId>
            <version>1.6.2</version>
            <exclusions>
                <exclusion>
                    <groupId>org.junit</groupId>
                    <artifactId>junit</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.powermock</groupId>
                    <artifactId>powermock-core</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.powermock</groupId>
                    <artifactId>powermock-reflect</artifactId>
                </exclusion>
            </exclusions>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.19.0-GA</version>
        </dependency>

Answer 1

Powermock 1.6.3 uses javassist 3.15.2-GA which does not support certain types. Using 3.18.2-GA javassist worked for me. You may want to override dependency in your project.

    <dependency>
        <groupId>org.javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.18.2-GA</version>
    </dependency>

You may face another problem for which the solution lies here Mockito + PowerMock LinkageError while mocking system class

Hope this helps.

Answer 2

So there seems to be issue with javassist (bytecode toolkit) prior to 3.18.2, as there's a resolved JIRA ticket-223.

1 - To find javassist version in your pom.xml, can use mvn dependency task

$ mvn dependency:tree | grep javassist
[INFO] |     \- org.javassist:javassist:jar:3.14.0-GA:compile

which is used by the powermock-module-junit4-rule ,

[INFO] +- org.powermock:powermock-module-junit4-rule:jar:1.4.9:test
[INFO] |  +- org.powermock:powermock-classloading-base:jar:1.4.9:test
[INFO] |  \- org.powermock:powermock-core:jar:1.4.9:compile
[INFO] |     \- org.javassist:javassist:jar:3.14.0-GA:compile

2 - So, updating the javassist version by explicitly to any versions >= 3.18.2 should work.

As, in my case, I am using use 3.20.0-GA

    <dependency>
        <groupId>org.javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.20.0-GA</version>
    </dependency>

Working eg. with scalatest

@PowerMockIgnore(Array("javax.management.*"))
@RunWith(classOf[PowerMockRunner])
@PrepareForTest(Array(classOf[Configurator]))
class LogServiceSpec {

  @Test
  def initialises_log4j2_on_each_instance_call() {
    PowerMockito.mockStatic(classOf[Configurator])

    val logService1 = new LogService
    PowerMockito.verifyStatic(Mockito.times(1))
    Configurator.initialize(Matchers.anyString(), Matchers.eq("log4j.config"))
  }
}

Answer 3

This is caused because of the conflict of dependencies. Resolving the dependency conflicts is one way to resolve this issue and the other way is to reorder <dependency></dependency> elements in your pom.xml. Move the powermock dependency declarations to the top of the <dependencies></dependencies> section. This is a complete hack and the right way to resolve it would be to resolve the dependency conflicts.

To identify those conflict you may use the command "mvn dependency:tree". Here is the dependency tree for my application for which I came across this same problem. Notice that there are two dependencies of "javassist" in the tree.

[INFO] +- org.mockito:mockito-core:jar:1.10.19:test
[INFO] |  +- org.hamcrest:hamcrest-core:jar:1.1:compile
[INFO] |  \- org.objenesis:objenesis:jar:2.1:compile
[INFO] +- org.powermock:powermock-module-junit4:jar:1.6.4:test
[INFO] |  \- org.powermock:powermock-module-junit4-common:jar:1.6.4:test
[INFO] |     +- org.powermock:powermock-core:jar:1.6.4:compile
[INFO] |     <span style="background-color: #FFFF00">|  \- org.javassist:javassist:jar:3.20.0-GA:compile</span>
[INFO] |     \- org.powermock:powermock-reflect:jar:1.6.4:compile
[INFO] +- org.powermock:powermock-api-mockito:jar:1.6.4:compile
[INFO] |  \- org.powermock:powermock-api-support:jar:1.6.4:compile
[INFO] +- org.slf4j:slf4j-log4j12:jar:1.7.14:compile
[INFO] |  +- org.slf4j:slf4j-api:jar:1.7.14:compile
[INFO] |  \- log4j:log4j:jar:1.2.17:compile
[INFO] |  +- org.apache.struts:struts2-core:jar:2.3.16.3-atlassian-6:provided
[INFO] |  |  \- ognl:ognl:jar:3.0.6:provided
<span style="background-color: #FFFF00">
[INFO] |  |     \- javassist:javassist:jar:3.11.0.GA:provided</span>
[INFO] |  +- com.atlassian:webwork-compat:jar:1.24:provided
[INFO] |  +- org.freemarker:freemarker:jar:2.3.16-atlassian-34:provided
[INFO] |  |  \- logkit:logkit:jar:1.2:provided
[INFO] |  +- opensymphony:sitemesh:jar:2.5-atlassian-6:provided
[INFO] |  +- commons-fileupload:commons-fileupload:jar:1.3.1:provided
[INFO] |  +- org.tuckey:urlrewritefilter:jar:4.0.3:provided
[INFO] |  +- velocity-tools:velocity-tools:jar:1.2:provided
[INFO] |  +- commons-dbutils:commons-dbutils:jar:1.3:provided
[INFO] |  +- org.hamcrest:hamcrest-all:jar:1.3:provided
[INFO] |  +- com.atlassian.bamboo:atlassian-user-crowd-provider:jar:5.10.0:provided
[INFO] |  |  +- com.atlassian.crowd:crowd-integration-client-rest:jar:2.7.2:provided
[INFO] |  |  |  \- com.atlassian.crowd:crowd-integration-client-common:jar:2.7.2:provided
[INFO] |  |  |     \- com.atlassian.security:atlassian-cookie-tools:jar:3.2:provided
[INFO] |  |  +- com.atlassian.crowd:crowd-integration-api:jar:2.7.2:provided
[INFO] |  |  |  \- com.atlassian.crowd:embedded-crowd-api:jar:2.7.2:provided
[INFO] |  |  +- com.atlassian.user:atlassian-user-api:jar:4.1.1:provided
[INFO] |  |  |  \- com.opensymphony.propertyset:api:jar:1.6.0-m1:provided
[INFO] |  |  +- com.atlassian.user:atlassian-user-ldap:jar:4.1.1:provided
[INFO] |  |  +- org.acegisecurity:acegi-security:jar:1.0.4:provided
[INFO] |  |  |  \- oro:oro:jar:2.0.8:provided
[INFO] |  |  \- com.atlassian.crowd:crowd-integration-seraph25:jar:2.7.2:provided
[INFO] |  +- javax.xml.stream:stax-api:jar:1.0-2:provided
[INFO] |  +- com.atlassian.core:atlassian-core:jar:5.0.2:provided
[INFO] |  |  \- com.atlassian.image:atlassian-image-consumer:jar:1.0.1:provided
[INFO] |  +- org.apache.maven:maven-embedder:jar:3.0.4:provided
[INFO] |  |  +- org.apache.maven:maven-settings:jar:3.0.4:provided
[INFO] |  |  +- org.apache.maven:maven-plugin-api:jar:3.0.4:provided
[INFO] |  |  +- org.apache.maven:maven-model-builder:jar:3.0.4:provided
[INFO] |  |  +- org.apache.maven:maven-compat:jar:3.0.4:provided
[INFO] |  |  +- org.codehaus.plexus:plexus-classworlds:jar:2.4:provided
[INFO] |  |  +- org.sonatype.sisu:sisu-inject-plexus:jar:2.3.0:provided
[INFO] |  |  |  \- org.sonatype.sisu:sisu-inject-bean:jar:2.3.0:provided
[INFO] |  |  +- org.codehaus.plexus:plexus-component-annotations:jar:1.5.5:provided
[INFO] |  |  +- org.sonatype.plexus:plexus-sec-dispatcher:jar:1.3:provided
[INFO] |  |  +- org.sonatype.plexus:plexus-cipher:jar:1.7:provided
[INFO] |  |  \- commons-cli:commons-cli:jar:1.2:provided
[INFO] |  +- org.apache.maven:maven-model:jar:3.0.4:provided
[INFO] |  +- com.octo.captcha:jcaptcha:jar:2.0-alpha-1:provided
[INFO] |  +- com.octo.captcha:jcaptcha-api:jar:2.0-alpha-1:provided
[INFO] |  +- com.jhlabs:filters:jar:2.0.235:provided
[INFO] |  +- org.apache.struts:struts2-sitemesh-plugin:jar:2.1.8.1:provided
[INFO] |  +- org.slf4j:jul-to-slf4j:jar:1.7.10:provided
[INFO] |  +- com.atlassian.plugins:atlassian-plugins-schema:jar:4.0.5:provided
[INFO] |  |  \- com.atlassian.plugins:atlassian-plugins-osgi:jar:4.0.5:provided
[INFO] |  |     +- com.atlassian.plugins:atlassian-plugins-osgi-events:jar:4.0.5:provided
[INFO] |  |     +- biz.aQute.bnd:biz.aQute.bndlib:jar:2.4.1:provided
[INFO] |  |     +- org.apache.felix:org.apache.felix.framework:jar:4.2.1:provided
[INFO] |  |     \- org.twdata.pkgscanner:package-scanner:jar:0.9.5:provided
[INFO] |  \- xerces:xercesImpl:jar:2.11.0:provided
[INFO] |     \- xml-apis:xml-apis:jar:1.4.01:provided
[INFO] +- junit:junit:jar:4.12:test
[INFO] +- info.cukes:cucumber-java:jar:1.2.4:test
[INFO] |  \- info.cukes:cucumber-core:jar:1.2.4:test
[INFO] |     +- info.cukes:cucumber-html:jar:0.2.3:test
[INFO] |     +- info.cukes:cucumber-jvm-deps:jar:1.0.5:test
[INFO] |     \- info.cukes:gherkin:jar:2.12.2:test
[INFO] +- info.cukes:cucumber-junit:jar:1.2.4:test
[INFO] +- com.atlassian.plugins:atlassian-plugins-osgi-testrunner:jar:1.2.3:test
[INFO] |  +- org.apache.wink:wink-client:jar:1.1.3-incubating:test
[INFO] |  |  +- org.apache.wink:wink-common:jar:1.1.3-incubating:test
[INFO] |  |  |  \- org.apache.geronimo.specs:geronimo-annotation_1.1_spec:jar:1.0:test
[INFO] |  |  +- javax.xml.bind:jaxb-api:jar:2.2:test
[INFO] |  |  \- com.sun.xml.bind:jaxb-impl:jar:2.2.1.1:test
[INFO] |  +- commons-io:commons-io:jar:1.4:provided
[INFO] |  \- com.atlassian.upm:upm-api:jar:2.15:test
[INFO] +- javax.ws.rs:jsr311-api:jar:1.1.1:provided
[INFO] +- com.google.code.gson:gson:jar:2.2.2-atlassian-1:compile
[INFO] +- com.mashape.unirest:unirest-java:jar:1.3.3:compile
[INFO] +- org.apache.httpcomponents:httpclient:jar:4.3.1:compile
[INFO] |  +- org.apache.httpcomponents:httpcore:jar:4.3:compile
[INFO] |  \- commons-codec:commons-codec:jar:1.6:compile
[INFO] +- org.apache.httpcomponents:httpasyncclient:jar:4.0:compile
[INFO] |  \- org.apache.httpcomponents:httpcore-nio:jar:4.3:compile
[INFO] +- org.apache.httpcomponents:httpmime:jar:4.3.1:compile
[INFO] +- org.json:json:jar:20090211:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.3.3:compile
[INFO] \- com.fasterxml.jackson.core:jackson-databind:jar:2.3.3:compile
[INFO]    \- com.fasterxml.jackson.core:jackson-annotations:jar:2.3.0:compile

I hope this helps.

Answer 4

In my case, a "java.io.IOException: invalid constant type: 18" was caused by multiple versions of javassist libraries in my classpath - both 3.12.1.GA and 3.18.2-GA. The problem disappeared when i removed the older one.