Generate Persistce Mapping - Mapped Type Follow

When trying to generate JPA Entitties with the option 'Generate Persistence Mapping' -> 'By Database Schema' for Oracle, the default Mappet Type for VARCHAR2 is java.lang.Object. Mapping for other DB types is not great either. This is really annoying, when one has to generate many entities with multiple fields, as one has to update the type manually. It is almost as though I was writing these Entities myself.

How do I configure what DB type get mapped to what Java Type???

IntelliJ IDEA version 15.0.3