Error handling in CommandServiceBean.execute

[boercher]

Hi,

a little bug in my test program in which I tried remote command execution took me quite a while to analyse. The problem was that instead of an error message indicating the real error I got this one:

ERROR [org.jboss.ejb.plugins.LogInterceptor] (WorkerThread#0[127.0.0.1:1264])
RuntimeException in method: public abstract java.lang.Object
org.jbpm.ejb.RemoteCommandService.execute(org.jbpm.command.Command)
throws java.rmi.RemoteException:
org.hibernate.exception.GenericJDBCException: Cannot open connection
...
at org.jbpm.JbpmContext.close(JbpmContext.java:129)
at org.jbpm.ejb.impl.CommandServiceBean.execute(CommandServiceBean.java:124)

The reason for the misleading error message was a missing try-catch block in CommandServiceBean.execute (in jbpm-3.2.6.SP1):

public Object execute(Command command) {
 JbpmContext jbpmContext = jbpmConfiguration.createJbpmContext();
 try {
 log.debug("executing " + command);
 return command.execute(jbpmContext);
 }
 catch (RuntimeException e) {
 sessionContext.setRollbackOnly();
 throw e;
 }
 catch (Exception e) {
 sessionContext.setRollbackOnly();
 throw new JbpmException("failed to execute " + command, e);
 }
 finally {
 jbpmContext.close();
 }
 }

The finally block performs some non-trivial cleanup-operations that easily may throw exceptions in case of a preceding error. Errors in command execution would be much easier to spot if the finally block would be coded like that:

finally {
 try {
 jbpmContext.close();
 }
 catch (Throwable t) {
 log.error("error on context close", t);
 }
 }

but development on 3.2 has been stopped, right?

Regards,
Volker

[boercher]

If this was not clear: The bug in my program caused a exception on command.execute(jbpmContext) which I only could see by debugging the CommandServiceBean since the exception from jbpmContext.close() hid the original one.

Corrrecting my proposal I'ld like to suggest that the exception from the finally block should only be ignored (i.e. only lead to an error message) if an exception has occured before.

Volker

[kukeltje]

sounds plausible, please file a jira issue for this.

[boercher]

Submitted as a patch: https://jira.jboss.org/jira/browse/JBPM-2133