JPA + DB Modeler
http://jpamodeler.github.io/tutorial/...
JPA Modeler is an open source graphical tool that enhances productivity and simplifies development tasks of creating complex entity relationship models. Using it developers can create JPA class & Database visually and automates Java code generation. The JPA Modeler provides forward & reverse engineering capabilities, import models from ODBC data sources, generate complex SQL/DDL and much more.
Visualize architecture
Visual creation of database structures
JPA 2.1 source generation
SQL/DDL script generation
for more info : http://jpamodeler.github.io/