Unable to load external jars while submitting Spark Job

We are using Jnius to call Java functions from Python. But when we are trying to submit the job using Spark,it is not able to load the java classes that are provided in the --jars option, although it is successfully able to load python class.
The Error is like this :
c = find_javaclass(clsname)
File "jnius_export_func.pxi", line 23, in jnius.find_javaclass (jnius/jnius.c:12815)
JavaException: Class not found