Java Persistence with Hibernate

16.3. Introducing the Command pattern

The patterns and strategies introduced in the previous sections are perfect if you have to write a small to medium sized web application with Hibernate and Java Persistence. The OSIV pattern works in any two-tiered architecture, where the presentation, business, and persistence layers are colocated on the same virtual machine.

However, as soon as you introduce a third tier and move the presentation layer to a separate virtual machine, the current persistence context can't be held open anymore until the view has been rendered. This is typically the case in three-tiered EJB application, or in an architecture with a rich client in a separate process.

If the presentation layer runs in a different process, you ...