Jython throws java.lang.ExceptionInInitializerError intermittently
The first thing to do is to read the exception.
About seven lines in, your exception says "Caused by: java.lang.NullPointerException".  I would focus on that.  Where is the null coming from?
Also note that your stack trace is missing some lines at the end, where it says "... 7 more".  This makes it hard to read the exception, because we don't know what the missing lines say.  See if you can find a way to show the missing lines, in case they are helpful.
I am a java person not well versed in jython or python.  So pardon my ignorance if this is a basic question.
I am using jython 2.5, python 2.5 and jre 1.7.
Intermittently, the jython interpreter fails to start, and is throwing an error like: 

Exception in thread "main" java.lang.ExceptionInInitializerError
   -        at java.lang.J9VMInternals.initialize(J9VMInternals.java:258)
   -        at org.python.core.PySystemState.initStaticFields(PySystemState.java:912)
   -        at org.python.core.PySystemState.doInitialize(PySystemState.java:882)
   -        at org.python.core.PySystemState.initialize(PySystemState.java:800)
   -        at org.python.core.PySystemState.initialize(PySystemState.java:750)
   -        at org.python.core.PySystemState.initialize(PySystemState.java:743)
   -        at org.python.util.jython.run(jython.java:150)
   -        at org.python.util.jython.main(jython.java:129)
   - Caused by: java.lang.NullPointerException
   -        at org.python.core.PyObject._cmpeq_unsafe(PyObject.java:1362)
   -        at org.python.core.PyObject._eq(PyObject.java:1456)
   -        at org.python.core.PyObject.equals(PyObject.java:244)
   -        at java.util.HashMap.put(HashMap.java:475)
   -        at java.util.HashSet.add(HashSet.java:217)
   -        at org.python.core.PyType.fromClass(PyType.java:1317)
   -        at org.python.core.PyType.fromClass(PyType.java:1275)
   -        at org.python.core.PyEllipsis.(PyEllipsis.java:14)
   -        at java.lang.J9VMInternals.initializeImpl(Native Method)
   -        at java.lang.J9VMInternals.initialize(J9VMInternals.java:236)
   -        ... 7 more

I did search the net, however I did not find any helpful information.
If anyone of you has solved this issue, please share.
Thanks
Ashoka