This tests the rollback logic of transaction. An EJB webservice is invoked by a servlet. This webservice method uses REQUIRED TX_Attribute. 

Here is the flow-

1. Standalone client invokes a servlet
2. Servlet creates table CUSTOMER_rb1 
3. Servlet starts a UserTransaction
4. Servlet adds a row in the CUSTOMER_rb1 table
5. Servlet calls the EJB webservice
6. EJB webservice adds a row in the CUSTOMER_rb1 table
7. Servlet rollback the transaction
8. It is checked that the data is not updated in the table.
9. Table CUSTOMER_rb1 is dropped