Error in beanshell - class not found in namespace

Question

We use beanshell to evaluate business rule validations on our application. Below is the calling method...
private Object callBeanShell(final Object parameters, final String expression)
throws EvalError {
if (LogConstants.FINE_ENABLED) {
logger.log(Level.FINE, "Expression: " + expression);
beanShell.set("params", parameters);
Object result = null;
try {
result = beanShell.eval(expression);
} catch (Throwable ex) {
getErrorHandler().fatalError("Expression: " + expression, ex);
if (LogConstants.INFO_ENABLED) {
logger.log(Level.INFO, "Expression: " + expression);
logger.log(Level.INFO, "Result : " + (result == null ? "null" : result.toString()));
return result;
This has been working fine on the application for years, but we've suddenly started getting a problem with evaluations which are called from a SessionBean (via some reflection).
Every time we try and call a certain set of expressions they fail on a 'class xxx not found in namespace'. This happens both when the expression contains code like:
com.chubb.euz.SomeClass sc = new com.chubb.euz.SomeClass(); etc...
or
import com.chubb.euz.SomeClass; SomeClass sc = new SomeClass(); etc...
The strange thing is that when I remote debug it & look at the bsh Interpreter what I see is that it's NameSpace object has a table called ImportedClasses on it which before the eval() call contains just bsh.Interpreter and bsh.EvalError but after the eval() it then contains all of the classes I pull in as imports in the expression passed to it, yet it still manages to throw this damn 'class not found in namespace' error!
It still works whenever else it's called in the app (and this is only happening in our DEV environment). All I can think of now is that it's possibly something to do with the Thread that the beanshell is running on at this time, but that's just a guess as I know bugger all about Threads... I only think this because I can get the thing to work by stopping the processor which was built to run Events (EJB) generated in the app; resetting the Event's Task (regular class) to run again; then restarting the processor (not an option if this goes into PROD with the release!!!)
Unfortunately, re-factoring the validations we need to run at this point is not really an option, as this is all coming at the tail end of a new release & the amount of code changes & subsequent regression testing required would kill us.
This is on weblogic 8.1 - with the beanshell jar just embedded in the main application ear (I ran it with bsh.20b4.jar instead of the 1.3 version we were using but that has no effect).
Any ideas would be more than gratefully appreciated as this is doing my head in!!!

Answer 1

Hi,
Thanks for the reply.
I am trying to reverse SAP tables. Initially the Reversal process stuck at Set MetaData step. I stopped the session and restarted it then Set MetaData completed successfully but Set FlexFields give the error.
Any idea?
Regards,
Arsalan.