Exception when mocking DataInputStream and then hibernate Query when using mockito-inline

I’m getting some very strange behavior in a very specific case when I have mockito-inline in my pom. I’ve reduced the issue to mocking java.io.DataInputStream and then attempting to mock org.hibernate.query.Query. When I do this, I get the following exception:

java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.query.Query$MockitoMock$131196958 at jdk.internal.reflect.GeneratedSerializationConstructorAccessor2.newInstance(Unknown Source) at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500) at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481) at org.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.newInstance(SunReflectionFactoryInstantiator.java:48) at org.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:73) at org.mockito.internal.creation.instance.ObjenesisInstantiator.newInstance(ObjenesisInstantiator.java:22) at org.mockito.internal.creation.bytebuddy.InlineDelegateByteBuddyMockMaker.doCreateMock(InlineDelegateByteBuddyMockMaker.java:370) at org.mockito.internal.creation.bytebuddy.InlineDelegateByteBuddyMockMaker.createMock(InlineDelegateByteBuddyMockMaker.java:328) at org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker.createMock(InlineByteBuddyMockMaker.java:56) at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:53) at org.mockito.internal.MockitoCore.mock(MockitoCore.java:84) at org.mockito.Mockito.mock(Mockito.java:1956) at org.mockito.Mockito.mock(Mockito.java:1871) at Test.test(Test.java:13) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:564) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63) at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329) at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.ParentRunner.run(ParentRunner.java:413) at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252) at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141) at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:564) at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189) at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165) at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85) at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115) at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)

Here is my test class (this has been boiled down to the absolute minimum required to reproduce the issue. Originally the DataInputStream mock and the Query mock were done in separate unit test classes, but got the same error):

import org.hibernate.query.Query;
import java.io.DataInputStream;
import java.io.IOException;
import static org.mockito.Mockito.mock;

public class Test {

    @org.junit.Test
    public void test() throws IOException {
        DataInputStream dataInputStream = mock(DataInputStream.class);
        Query mockQuery = mock(Query.class);
    }
}

Here is my pom:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>Test</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-inline</artifactId>
            <version>4.0.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.6.0.Final</version>
        </dependency>
    </dependencies>
</project>

I’m on windows 10

java --version java 17.0.1 2021-10-19 LTS Java™ SE Runtime Environment (build 17.0.1+12-LTS-39) Java HotSpot™ 64-Bit Server VM (build 17.0.1+12-LTS-39, mixed mode, sharing)

check that

• The mockito message in the stacktrace have useful information, but it didn’t help
• The problematic code (if that’s possible) is copied here; Note that some configuration are impossible to mock via Mockito
• Provide versions (mockito / jdk / os / any other relevant information)
• Provide a Short, Self Contained, Correct (Compilable), Example of the issue (same as any question on stackoverflow.com)
• Read the contributing guide

[TimvdLippe]

It is advised not to mock classes you don’t own: https://github.com/mockito/mockito/wiki/How-to-write-good-tests#dont-mock-a-type-you-dont-own We are working on improving the user experience by working on a DoNotMock feature to avoid mocking classes/methods that are known to crash Mockito internals (#1833).

[smas321]

Thanks @raphw, @TimvdLippe, makes sense to not mock JVM core lib classes. Is there any documentation or guidance on this which elaborates? I’ve had a look but could not find any. I’m working with some legacy tests and would like to fix them.