Migrating a Struts/Java E-Mail Application to Lift/Scala
Christoph Knabe, Thomas Fiedler

At the Beuth Technical University of Applied Sciences Berlin (BHT) we are using since 2003 a Java web application "teacher news", by which students are e-mailed about important events relating to their teachers. Persons, subscriptions, and messages are stored in a database for web access. We report decisions and experiences in migrating this application to Lift/Scala.
The topics covered are: The Mapper OR-Mapping framework; Problems in separating user interface from business logic; Comparison with JPA and Hibernate; How to get quickly an application without scaffolding; Configuring Lift by the LiftRules and S objects; The abundance of singleton objects in Lift and its relation to dependency injection; How to do transaction processing with Lift/Mapper; How to do central, and local exception reporting with Lift; How to do URL rewriting; How did we use CometActors to visualize successing, and failing e-mailing; Our tool ScalaSnipper for extracting code snippets for publication.