Pushed Jena version to 5.0.0 and updated Caching library

[jerdebsp]

Hi,

I was having trouble using 1.4.3 due to Jena classes deprecated or removed - more specifically org.apache.jena.graph.Factory. In my pull request, i've updated Jena to the latest version and also updated the Caching library to use benmanes (https://github.com/ben-manes/caffeine) which is compatible with the previously used library. I believe that the library used in the main fork is not available anymore.

Thanks,
Jeremy

PS. I couldn't assign anyone as reviewer. I guess Holger or Ashley can do this.

[afs]

Minor: Should this be a call to `JenaUtil.createDefaultGraph()?

[jerdebsp]

For some reason JenaUtil.createDefaultGraph() is calling the helper class, causing a stack overflow cycle

This is what there is in JenaUtil.
public static Graph createDefaultGraph() { return helper.createDefaultGraph(); }
Maybe this needs to be changed?

[costas80]

Hey @jerdebsp . Is this PR blocked? I see discussion about a stack overflow from the review by @afs but no clear resolution.

[jerdebsp]

That comment was for why I did not use JenaUtil.createDefaultGraph(). I think the PR is still blocked for now until Java (on the CI) is updated from 17 to 21 or 22.

If you are using java 21 or 22, you can download my branch and use it. I am using it for project work and training and so far it seems to work well

[afs]

The latest Jena release is 5.2.0.

[costas80]

@jerdebsp, if you update Jena to the latest version, maybe @ashleycaselli, or @HolgerKnublauch could have a look at the CI issue and merge this?

[jerdebsp]

I will try to update to Jena 5.2.0 by end of next week

[jerdebsp]

I tested 5.2.0 on my machine and seems to work, however, it only makes sense to update once this PR is merged.

[ashleycaselli]

@jerdebsp can you please update the JDK used in the maven-test-pr.yml to Java 17 (Jena5 requires that)? Also, before merging the PR we would need to update the JRE versions used as base images for building the docker image (docker-image.yml).

[jerdebsp]

@ashleycaselli done. when this is merged i'll move with updating to 5.2.0

[ashleycaselli]

@ashleycaselli done. when this is merged i'll move with updating to 5.2.0

Thanks!

Lastly, the maven-compiler-plugin is building the code against Java 11. That means that even if Maven/Docker image now run on JDK 17, when the package is released it's compiled following Java 11 specifications. To avoid any compatibility issues at this stage I would keep that Java version in sync with the JDK version used. However, before making any changes I'd wait for @HolgerKnublauch 's point on this.

[HolgerKnublauch]

Don't wait for my feedback here as I don't really have time to follow the details of this repo anymore. We have completely moved in our code base to Java 17 last year and didn't encounter problems.

[afs]

For docker, the image can jump to Java21 runtime, even if the code only requires Java17.

Jena already builds with Java21 (targeting Java17) and runs on Java21.

Java25 is LTS in September 2025. Sometime after, when it's clear Java25 is established, Jena will highly likely move to supporting Java21 and Java25, dropping Java17.

Apache Lucene 10 requires Java21.

[ashleycaselli]

I merged this PR into the 177-jena5 branch.

@jerdebsp do you want to bump Jena to v5.2 into that branch and then I merge into master when it's ready to be released?