Add module-info.java to the project and its dependencies

[Adito5393]

Thanks a lot for sharing this library.

Would you be open to a PR for adding module-info.java to the project and its dependencies (lti-13-core & lti-13-jwt)?

The most important changes would be:

1. Minimum Java version would change from 8 to 9+
2. Some dependencies might need to be upgraded to fix issue Test errors seem to prevent successful build #16 (PR Made the build to be compatible with JDK13 environments by bumping some versions. Also just some import cleanup #5 shows the fix)

I would be willing to also configure Github actions to help you accept PR like #5 faster and easier.

[xaviaracil]

Hi!

We have some apps in JDK 8. So, for making your proposed changes, we will have to branch JDK 8 version. I'll do it (and your PR's) next week.

Thanks!

[Adito5393]

Great to hear that you are actively maintaining the library.

Indeed, the option of maintaining 2 branches for the library is easy to implement and it will fix the problem in the short run.
I think that it will add extra manual work in the long run (unless the branch synchronization is automated).

I would propose looking into the Multi Release feature via the maven-compiler-plugin. There should also be a Multi-Release JAR Check.

I, personally, never implemented it, however, I am willing to look into it and if it's not too much work, I could even supply a working version of the library for you to test out within your applications (JDK 8) and we can work towards a stable release deployment.

PS: I am not the author of PR #5. After checking the changes within that branch, there are many aesthetic changes, like replacing spaces with tab. Review it carefully and run your format IDE over the whole project to keep it consistent.
Alternatively, you could automate the format process via a maven plugin as part of the maven lifecycle on each developer machine, or, on the Github repo source code via the Github Actions for every PR/push event. (Check out the google-java-format repo or the formatter-maven-plugin).

Did you already know about the multi-release? What do you think about it? Do you think it is worth the extra hassle to keep the library in sync via JDK + maven?

[xaviaracil]

I'm not aware of the multi-release. I know supporting JDK 8 nowadays may seem a loss of time and effort, but still there are some applications using it. However, I'd rather suggest to move to JDK 9 (or 11) and don't mess the library with some compatibility hacks that won't last for too long. So, our plans is to upgrade our applications to, at least, JDK 11, so that multi-release version won't be necessary.

Said that, It's only my opinion. If you find a working version compatible with JDK 8 that we can use would be very helpful for us, giving us extra time to upgrade our applications.

For this repo, I suggest keeping a JDK 8 branch, and move main branch to supported JDK versions. What do you thing?

[Adito5393]

Awesome, raising the java minimum requirement to JDK11 is fine with me. I don't have any good argument to keep JDK 8 support alive.

Ping me here, when you have the JDK11 branch ready.
I can help out with 2 tasks:

1. The module-info.java creation, testing, debugging, etc...
2. Github actions CI/CD to automate the process for maven compile & testing for each Pull Request

EDIT: I would recommend the following repo management changes:

1. Bumping the version number to 2.x.x for the JDK 11 branch and keeping the same artifactId lti-13-core. This way, the JDK8 branch can continue to be updated under version 1.x.x.
2. Keep the master/main/default branch using the artifactId name ending with -SNAPSHOT & only remove it during a release phase (when a git tag is created). (it is following the gitflow-workflow where the master/main and develop are the same branch).

What do you think?

[Adito5393]

Check out my changes and let me know to which branch would you like the PR

[xaviaracil]

Great! Since the main branch must contain jdk11+, in my opinion, I'd suggest to create a JDk1.8 branch.

Agree with the management changes.