In my application setup i want to update DB schama changes to the DB.

since i have hbm files for all the tables, i thought of using the UpdateSchema mechanism.

I saw there is no tool for validating the schema, so i want to write one of my own. but when i looked at the hibernate sources, i was surprise to see that it is difficult to do it, since the "tables" memeber in the Configuration class is private and there is no way to access it (even if i want to inherite from Configuration to add functionality)

why is it writen this way? it is also very difficult to add functionality to the ExportSchama from the same reasons....

Hibernate Tools has this feature.

I am sorry, see chapter 15 of the hibernate documentation for the tools.
http://www.hibernate.org/hib_docs/reference/en/html/toolsetguide.html

getTableMappings() will probably be public in H3.

But besides that you should be able to get to all the tables by going through all the class mappings...at least as a workaround.