getting hibernate default schema name programmatically from session factory?

This will do the trick:

  SessionFactoryImplementor sfi = (SessionFactoryImplementor) getSessionFactory();           
  Settings settings = sfi.getSettings();
  ConnectionProvider connectionProvider = settings.getConnectionProvider();
  try {
        Connection connection = connectionProvider.getConnection();
        DatabaseMetaData databaseMetaData = connection.getMetaData();
        String url = databaseMetaData.getURL();
        //substring the string to what you want
        System.out.println(url);
  } catch (SQLException e) {
       //throw something
  }

I just found out that hibernate has {h-schema} replacement that can be used in native sql queries. So this does the job cleanly when you are connected to a one schema in oracle database and want to execute queries against different schemas. Example would be:

select * from {h-schema}table_name

This ways instead of doing a manual replaceAll in a query, hibernate will take care of everything given that each session factory is configured with "hibernate.default_schema" property.

I had problems with John's solution to use {h-schema} when using the Criteria api's Restrictions.sqlRestriction(...) (probably because this substitution happens within the separate HQL api). Similar to Michael's solution, I used:

SessionFactoryImplementor sfi = (SessionFactoryImplementor)sessionFactory;
String name = sfi.getSettings().getDefaultSchemaName();