Exception when trying to execute the Jar file

[psygo]

I know this isn't really about Shin KGS, but does anyone know how to get around this?

I'm using Artix (Arch Linux), and I do have Java installed.

This is the error message I get:

$ java -jar cgoban.jar 
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/igoweb/cgoban/CGoban : Unsupported major.minor version 52.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:808)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:443)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:65)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:349)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:348)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:430)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:326)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:363)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

Do I have to install an older Java version? If so, does anyone know which one?