Running Java Program on Manjaro Linux

Question

I am experimenting with OPCAT for simple systems egnineering models. I know that there is a newer cloud version, but it does not allow sharing and saving models, so I stick with the old OPCAT.

It is a java-application and on a windows machine it runs using

java -Xmx1024m -Dopcat.home="%APPDATA%\Opcat" -Dopcat.source="C:\Program Files (x86)\Opcat\Opcat.Structure" -jar "C:\Program Files (x86)\Opcat\Opcat2.jar"

following that logic I converted the terminal input to

java -Xmx1024m -Dopcat.home="/home/dh/opcat" -Dopcat.source="/home/dh/opcat/Opcat.Structure" -jar ~/opcat/Opcat2.jar

unfortunately I get errors (selection, actual output much longer):

log4j:ERROR setFile(null,true) call failed. java.io.FileNotFoundException: opcat-log.xml Exception in thread "main" java.lang.NoClassDefFoundError: sun/misc/BASE64Decoder

I tried java-15-openjdk and java-16-jdk, the result was alwayas the same. Websearching the problem resulted in me setting different CLASSPATHs, with no effect.

There are many texts out there leading down the rabbit hole of java developing, but I simply do not have the capacity to dig into them. I really hope I get a simple solution for the problem, since I am process engineer and nowhere close to a software developer (which I regret alot).

I am using manjaro linux, the OPCAT jar-file can be found here: http://esml.iem.technion.ac.il/opcat-installation/ (very last bullet point). I tried the "How to Install OPCAT on MAC"-help file, but was not lucky.

I don't know what to expect here, maybe you can point out the right direction. Thanks..

Answer 1

You have an old version of OPCAT which was developed with an old version of Java. Oracle removed the class sun.misc.BASE64Decoder with Java 9, so you need Java 8 to run it.

I highly recommend using SDKMAN to manage different versions of SDKs on your system.