jdk11 JAR shows up even with <classifier>jdk8</classifier>

[pcurrivan]

I'm using JDK8 and I have the classifier tags in my pom file.

I got this error:
Exception in thread "main" java.lang.UnsupportedClassVersionError: de/bytefish/pgbulkinsert/mapping/AbstractMapping has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

In my target folder I found the two jdk8 jars (core and rowwriter) as well as a jdk11 core jar. Deleting the jdk11 jar (pgbulkinsert-core-7.0.1.jar) seems to make things work properly.

[bytefish]

Could you share the relevant parts of the pom.xml, so I can give it a try.

[bytefish]

If you are using IntelliJ I found a somewhat similar problem described here:

• Maven dependencies are downloaded with wrong classifier arnaudroger/SimpleFlatMapper#677

Could you have a look if this applies to the issue here, too?

[bytefish]

Oh well I should have read the whole thread, the author built the project with different artifactId names. I will keep investigating.

[bytefish]

It's apparently the project described here:

• https://youtrack.jetbrains.com/issue/IDEA-203432

I will see how complicated it is to update the artifactId, because honestly... this bug in IntelliJ has been not fixed for some years... and I don't think this is obvious to most people.

In the meantime, maybe you can set the JDK in IntelliJ to the projects JDK.

[bytefish]

Does it help to add this to your pom.xml:

<properties>
  <maven.compiler.source>1.8</maven.compiler.source>
  <maven.compiler.target>1.8</maven.compiler.target>
</properties>

Also see:

• https://stackoverflow.com/questions/25888023/how-to-change-java-version-for-maven-in-intellij

[pcurrivan]

Thanks for the prompt response. I can't share much of the pom, but I did run mvn dependency:tree and I see that the jdk8 rowwriter depends on the jdk11 jar:

[INFO]    +- de.bytefish.pgbulkinsert:pgbulkinsert-core:jar:jdk8:7.0.1:compile
[INFO]    +- de.bytefish.pgbulkinsert:pgbulkinsert-rowwriter:jar:jdk8:7.0.1:compile
[INFO]    |  \- de.bytefish.pgbulkinsert:pgbulkinsert-core:jar:7.0.1:compile

Maybe you need to add a classifier or something to the rowwriter pom dependencies?

My IDE's importer was already using 1.8. The source and target properties did not help.

[bytefish]

@pcurrivan Thanks, I will create a small sample today and try to reproduce it. @jonfreedman Can you see a problem with the definition for the JDK8?

[jonfreedman]

I'm not sure maven allows us to refer to the current project classifier in order to express that as a dependency. For now you should be able to fix this by excluding the transitive dependency of pgbulkinsert-core from pgbulkinsert-rowwriter.
We'll take a look at improving the way we support Java 8 vs Java 11