This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Take a look at java.sql.Connection.setTransactionIsolation().
However, note that not all databases support transactions, and those that do, support different levels. The level of transaction support in MySQL varies depending on the table type you are using, with the default being no transactions. You might want to find out more about your particular database installation before deciding how much to depend on transactions.