Performing a Hibernate reverse engineering in Netbeans leads to a NullPointerException in the wizard.
Looking at the Hibernate (3.2) and Netbeans code involved, the problem seems to be in the way that Netbeans creates the connection in org.netbeans.modules.hibernate.util.CustomJDBCConnectionProvider and this somehow leads to a null connection being returned from Firebird. This might be a classloading issue.
The specific code (which matches with the logging in Netbeans) in CustomJDBCConnectionProvider (based on 7.3.1 source) is:
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
Class clazz = classLoader.loadClass(driverClassName);
java.sql.Driver driver = (java.sql.Driver) clazz.newInstance();
logger.info("Loaded JDBC driver ");
// Establish the connection
java.util.Properties info = new java.util.Properties();
connection = driver.connect(driverURL, info);
logger.info("Got connection.. returning");
Looking at org.firebirdsql.jdbc.FBDriver this can only return null if GDSFactory.getTypeForProtocol(url); does not return a GDSType, which should only happen if the URL is not a Firebird url.