Jacoco - "Caused by: java.lang.ClassNotFoundException: org.jacoco.agent.rt.internal_6da5971.Offline"

Question

Trying to get coverage via jacoco using offline instrumentation (can't use on-the-fly instrumentation: due to powermock testcases) for a maven project.Added the jacocoagent.jar to classpath in surefire plugin as shown below. Renamed the "org.jacoco.agent-0.7.7.201606060606-runtime.jar" (from local maven repository) to "jacocoagent.jar" and kept that in the same folder where this pom.xml is residing.I'm hitting the below exception even after adding it to classpath.

snippet of pom.xml (surefire - plugin configuration)

       <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-surefire-plugin</artifactId>
             <configuration>
                     <forkmode>once</forkmode>
                    <additionalClasspathElements>
            <additionalClasspathElement>jacocoagent.jar</additionalClasspathElement>
                                        </additionalClasspathElements>
              </configuration>
     </plugin>

Exception seen on console:

#############
Number of foreign imports: 1
import: Entry[import  from realm ClassRealm[maven.api, parent: null]]

-----------------------------------------------------

        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:166)
        ... 21 more
Caused by: java.lang.NoClassDefFoundError: org/jacoco/agent/rt/internal_6da5971/Offline
        at com.cisco.ise.ups.modelframework.hibernate.OracleNamingStrategy.$jacocoInit(OracleNamingStrategy.java)
        at com.cisco.ise.ups.modelframework.hibernate.OracleNamingStrategy.<clinit>(OracleNamingStrategy.java)
        at sun.misc.Unsafe.ensureClassInitialized(Native Method)
        at sun.reflect.UnsafeFieldAccessorFactory.newFieldAccessor(UnsafeFieldAccessorFactory.java:43)
        at sun.reflect.ReflectionFactory.newFieldAccessor(ReflectionFactory.java:142)
        at java.lang.reflect.Field.acquireFieldAccessor(Field.java:1082)
        at java.lang.reflect.Field.getFieldAccessor(Field.java:1063)
        at java.lang.reflect.Field.get(Field.java:387)
        at com.cisco.ise.ups.build.WorkflowRunnerMojo.namingStrategyInstance(WorkflowRunnerMojo.java:335)
        at com.cisco.ise.ups.build.WorkflowRunnerMojo.setupWorkflowEnvironment(WorkflowRunnerMojo.java:514)
        at com.cisco.ise.ups.build.WorkflowRunnerMojo.execute(WorkflowRunnerMojo.java:816)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
        ... 21 more
Caused by: java.lang.ClassNotFoundException: org.jacoco.agent.rt.internal_6da5971.Offline
        at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
        ... 33 more
[ERROR]
###############

Steps followed:

1. "mvn compile" .
2. "mvn org.jacoco:jacoco-maven-plugin:instrument"
3. "mvn test" - Exception raised at this step.

Please let me know of how to get rid of this exception ? Was that the right place to add classpath?? (in surefire plugin) OR should it be specified some where??

Thank you.

Answer 1

The classpath stuff on the surefire plugin is not necessary. You need to add a dependency to each module that has tests, like this:

<dependency>
    <groupId>org.jacoco</groupId>
    <artifactId>org.jacoco.agent</artifactId>
    <classifier>runtime</classifier>
    <scope>test</scope>
    <version>${your.jacoco.version}</version>
</dependency>

Make sure you don't miss the "classifier" part, or it won't work.

Full example from PowerMock project