Mogwai ERDesignerNG has a built-in export module for OpenXava.
The Mogwai ERDesigner is a entity relation modeling tool such as ERWin and co. The only difference is that it is Open Source and does not cost anything. It was designed to make database modeling as easy as it can be and to support the developer in the whole development process, from database design to schema and code generation. This tool was also designed to support a flexible plug in architecture, to extend the system simply by installing a new plug in. This way, everybody can implement new features and tools to make ERDesigner fit the requirements.
Mogwai ERDesignerNG models can be exported to OpenXava annotated Java classes. Using this feature, rapid application development is as easy as never before! Please refer to the ERDesignerNG user documentation for more information about this outstanding feature!