You get the following exception after making the modifications shown below in your example ProcessTaskTest.java
1.) Use different emfTask as you had suggested(EntityManagerFactory emfTask = Persistence.createEntityManagerFactory( "org.jbpm.myTask" );)
2.) Use WSHumanTaskHandler and Mina (i.e uncomment Mina code and the following line)
//ksession.getWorkItemManager().registerWorkItemHandler("Human Task", new WSHumanTaskHandler());
[2011:03:88 14:03:888:exception] Error while commiting the transaction
javax.persistence.RollbackException: Error while commiting the transaction
at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:71)
at org.jbpm.task.service.TaskServiceSession.doOperationInTransaction(TaskServiceSession.java:716)
at org.jbpm.task.service.TaskServiceSession.addTask(TaskServiceSession.java:134)
at org.jbpm.task.service.TaskServerHandler.messageReceived(TaskServerHandler.java:108)
at org.jbpm.task.service.mina.MinaTaskServerHandler.messageReceived(MinaTaskServerHandler.java:41)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:713)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
..
....
Caused by: org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
....
Caused by: java.sql.BatchUpdateException: ORA-02291: integrity constraint (NAGIOS.FK27A9A56CE1EF3A) violated - parent key not found
at oracle.jdbc.driver.DatabaseError.throwBatchUpdateException(DatabaseError.java:602)
at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:9350)
at oracle.jdbc.driver.OracleStatementWrapper.executeBatch(OracleStatementWrapper.java:210)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)