Hattori is a Java framework that simplifies Data Transfer Object population in n-tier web applications by using Java 5 annotations.

The framework is meant to be used at service layer and presentation layer. Given a domain object graph, a DTO object model subset is populated by Hattori which becomes available for modification which will could be later taken to the original domain object graph. Normally, the DTOs are populated at the service layer and sent to the presentation layer for that modification.

The population process is done by evaluating each Data Transfer Object annotated with the ObjectPopulation annotation, identifying operations to be executed on each one using one of these options: implicit rules, annotation rules or your own specific per-object defined java code.