Upgrading Maven plugins to Java 11

November 12, 2021

I am upgrading my Maven-built, Java 8 app to Java 11. In my POM I specify:

<properties>
  <java.version>1.11</java.version>
  <maven.compiler.source>${java.version}</maven.compiler.source>
  <maven.compiler.target>${java.version}</maven.compiler.target>
</properties>

When I go to build my app using my normal Maven build invocation:

mvn verify -Plocal -Dspring-boot.run.jvmArguments="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"

I get:

[INFO] Scanning for projects...
[INFO] 
[INFO] -----------------------< example.com:myapp-svc >------------------------
[INFO] Building myapp-svc 1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-checkstyle-plugin:3.1.2:check (validate) @ myapp-svc ---
[WARNING] Old version of checkstyle detected. Consider updating to >= v8.30
[WARNING] For more information see: https://maven.apache.org/plugins/maven-checkstyle-plugin/examples/upgrading-checkstyle.html
[INFO] Starting audit...
Audit done.
[INFO] You have 0 Checkstyle violations.
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.7:prepare-agent (default) @ myapp-svc ---
[INFO] argLine set to -javaagent:/Users/myuser/.m2/repository/org/jacoco/org.jacoco.agent/0.8.7/org.jacoco.agent-0.8.7-runtime.jar=destfile=/Users/myuser/workspace/myapp-svc/target/jacoco.exec
[INFO] 
[INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ myapp-svc ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 6 resources
[INFO] Copying 154 resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ myapp-svc ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 456 source files to /Users/myuser/workspace/myapp-svc/target/classes
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.076 s
[INFO] Finished at: 2021-11-12T12:52:52-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project myapp-svc: Fatal error compiling: error: invalid target release: 1.11 -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

So it looks like the maven-compiler-plugin:3.8.1 plugin is incompatible with Java 11. The thing is, I don’t directly specify that plugin anywhere in my POM. So something, somewhere is pulling it and using it, and my guess is that I have to update whatever that thing is so that it pulls in a version of the maven-compiler-plugin that is compatible with Java 11.

So how can I tell what’s pulling it in and using it? Or if thats not what’s happening, what is and how do I fix it?