How could I run a local jar file from a java program?
The jar file is not in the class-path of the Java caller program.
I suggest you use a ProcessBuilder
and start a new JVM.
Here is something to get you started:
ProcessBuilder pb = new ProcessBuilder("/path/to/java", "-jar", "your.jar");
pb.directory(new File("preferred/working/directory"));
Process p = pb.start();