Sophistication!!

Can't ever imagine how complicated it is to set up a connection between Tomcat and MySQL server, it is the first time I am doing so, and have encountered (and tackled) tonnes of problems in one afternoon, yet stage after stage the error messages are becoming more weird and low-level.
First is simple form bean problem, and then OJB repositories, then database authentication, and database field, then "connectionManager NOT in transaction", and now "can't borrow transaction from ConnectionPool. I tried many methods from web and learnt a lot today, yet the problem overall remains unsolved...