Junit Mockito error on initialization

Question

I have looked everywhere online. I have tried almost everything, from deleting STS to deleting all the code from my station and re-import everything back. I played with dependencies, build path, properties, etc. but still nothing works.

Running the tests on Maven by CLI is working fine, and other team members don't have that issue, so it is probably some configuration on my station.

The problem:

When I try to debug/run a unit test inside STS using JUnit v. 4 I get an error with the following stack trace:

java.lang.IllegalAccessError: class org.mockito.internal.creation.jmock.ClassImposterizer$1 cannot access its superclass org.mockito.internal.creation.cglib.MockitoNamingPolicy
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.mockito.internal.creation.jmock.ClassImposterizer.<clinit>(ClassImposterizer.java:38)
at org.mockito.internal.creation.CglibMockMaker.createMock(CglibMockMaker.java:23)
at org.powermock.api.mockito.internal.mockmaker.PowerMockMaker.createMock(PowerMockMaker.java:43)
at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:33)
at org.mockito.internal.MockitoCore.mock(MockitoCore.java:59)
at org.mockito.Mockito.mock(Mockito.java:1285)
at org.mockito.internal.configuration.MockAnnotationProcessor.process(MockAnnotationProcessor.java:33)
at org.mockito.internal.configuration.MockAnnotationProcessor.process(MockAnnotationProcessor.java:16)
at org.mockito.internal.configuration.DefaultAnnotationEngine.createMockFor(DefaultAnnotationEngine.java:43)
at org.mockito.internal.configuration.DefaultAnnotationEngine.process(DefaultAnnotationEngine.java:66)
at org.mockito.internal.configuration.InjectingAnnotationEngine.processIndependentAnnotations(InjectingAnnotationEngine.java:71)
at org.mockito.internal.configuration.InjectingAnnotationEngine.process(InjectingAnnotationEngine.java:55)
at org.mockito.MockitoAnnotations.initMocks(MockitoAnnotations.java:108)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl$1.withBefores(JUnit45AndHigherRunnerImpl.java:27)
at org.junit.runners.BlockJUnit4ClassRunner.methodBlock(BlockJUnit4ClassRunner.java:254)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
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)

If anyone have any idea on what the problem might be...

Here is part of the POM:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.2.RELEASE</version>
    <relativePath>org.springframework.boot:spring-boot-starter-parent</relativePath>
</parent>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
        <groupId>com.mockrunner</groupId>
        <artifactId>mockrunner</artifactId>
        <version>0.3.1</version>
    </dependency>

Answer 1

spring-boot-starter-test 1.4.2.RELEASE uses Mockito 1.10.19 by default, org.mockito.internal.creation.jmock.ClassImposterizer doesn't exist in 1.10.19. It's now in the org.mockito.internal.creation.cglib package.

Exclude org.mockito from spring-boot-starter-test, as follows:

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.mockito</groupId>
                    <artifactId>mockito-core</artifactId>
                </exclusion>
            </exclusions>
</dependency>

And include mockito-all 1.9.5 as a dependency:

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>1.9.5</version>
    <scope>test</scope>
</dependency>

Answer 2

This happens when there are multiple versions of mockito. Exclude mockito version which is being transitively brought by other dependencies.

<exclusion>
 <artifactId>mockito-all</artifactId>
 <groupId>org.mockito</groupId>
 </exclusion>

This worked in my case.

Answer 3

In my case I had added correct jars in project build path. But the test case's run configuration classpath had different jars. Correcting the run configuration of junit test worked for me.

Answer 4

in my case, while generating the Sonar report, it requires us to delete some jar files related to Mockito framework. So, while running the jUnits, I faced this issue and found out that two jar files (mentioned below) were not present in the codebase.

1. mockito-all-1.9.5.jar
2. mockito-core-1.10.19.jar

You need to navigate to {platform home}/ext/core/lib folder and check for the files. If not present, run ant customize all one of the above two jar files will be generated in the folder mentioned above. Then run ant unittests and the second jar file will also be generated according to your Mockito version. Save these two files at some other location. Then place these files again in {platform home}/ext/core/lib path and try. It will definitely work.