Looking for help getting started with bringing a .jar into a c# .net project

[tovversh]

I've been working away at this for a couple of days, and I'm sure I'm missing something simple, but I just can't figure out what it is.

So to start off I have a .jar file from an outside source that I would like to run with my c# .net project. IKVM seems to be designed for that so I've tried to get it to work without much luck

So here is what I did: ( Using Visual Studio 2019 )

1. Created a new Class Library ( .Net Framework )
   • Set the .Net Framework to 4.7.2 ( To match the project that will use the resulting library)
2. Added the NuGet package for IKVM (8.5.1 )
3. Added the Nuget package for IKVM.MSBuild (8.5.1 )
4. Saved and closed the solution.
5. Opened the .proj file in the editor and added:

Reporter Reporter.jar 6. I opened the default Class1.cs and added a #using to the namespace from the .jar and added a function to the class to call the 'main' from the .jar. 7. Then I did a full rebuild.

The rebuild doesn't recognize the namespace from the .jar and fails. The only error it gives me is not recognizing the namespace. I see no indication that anything is happening with regards to the IkvmReference to bring in the contents of the .jar.

I've ran the .jar file with the java.exe included with IKVM and it operated successfully, so the .jar is basically good.

At this point I'm not sure what to do next. I'm feeling like I'm missing something simple, but haven't been able to figure it out. Any help would be greatly appreciated.

[wasabii]

Make sure the project is a SDK style project. We do not support old style csproj formats.

[tovversh]

Ah, that would make sense. I am not the source of the Jar and I don't have access to it's source ( though I will run around and check). I just want a way to run it and get back the results without needing java installed. I don't suppose there is a way to trap or block the System.exit(0) call?

[wasabii]

Nothing that would be special to IKVM.

But you don't have to call main.

[wasabii]

You can decompile it and take a look. Either in a Java tool, or the DLL in a .net tool

[tovversh]

Thanks a lot for the tips. I was able to get into the jar file, decompile and edit the classes and remove a couple of the offending System.exit calls and got the resulting jar to run without forcing my application to exit. So that should resolve that problem in principle.

That leaves me with one remaining issue. It looks like the jar is directing many important bits of output through System.out.println. I am not seeing them in the Visual Studio debug window when I run the application. Do you know where IKVM would direct that output and if there would be any way in the c# that I might capture that.

Again, thank you very much for your help.

[wasabii]

IKVM doesn't do anything special to it. It's Console.Output. stdout.

Which doesn't show in a Win Exe where there is no attached console.