Minimum java version

Does VTK require a minimum version of Java to compile its wrapper code?

I think 1.6 or 1.7 is mentioned? It should work with pretty old versions and may have various deprecation warnings from newer versions.

Cc: @dgobbi

The wrappers should build with JDK 1.6 up to JDK 1.11 at least.

Ok. Thanks guys.

So hopefully no one would mind a minimum requirement of Java version 1.7 then?

I’m working on an MR to significantly improve the efficiency of the Java wrappers with respect to string handling for utf8 conversion. It uses StandardCharsets, which is supported for 1.7+

That sounds fine to me. Java 6 extended support ended in 2018.

I see no issues with moving to 1.7. The last time I built against 1.6 would have been back in 2018, I think.

From memory I have built VTK with Java 12 way back in 2019. I think that there were a few deprecation warnings, however as I wasn’t really using Java except for testing VTK Examples I stopped enabling the wrapping as it takes a very long time to build in comparison to the Python wrapping.

Building the Java wrappers is quick on Windows with VS, but terribly slow on Linux with vscode.

I don’t know if it’s because I’m using a VM for Linux, or the different compilers and OS.

I was building with VS2019/ninja on Windows and on Linux using gcc/ninja, so these were native systems not VM. The builds did take a while but I don’t remember whether Linux took longer or Windows 10 took longer. However the building did take a long time.

Here’s the associated MR https://gitlab.kitware.com/vtk/vtk/-/merge_requests/7628