public void preLogin(SessionEvent event) {
       
		DatabasePlatform dp = (DatabasePlatform) event.getSession()
				.getDatasourcePlatform();
		dp.addStructConverter(new Foo1Converter());
		dp.addStructConverter(new Foo2Converter());

		System.out.println("MySessionEventListener.preLogin() StructConverters- " + dp.getStructConverters());	
		
		// Iterate over the descriptors
		// Identify DirectToFieldMappings for our structured types
		// 	Set converter to null
		// 	Set field type to java.sql.Types.STRUCT

		Map<Class, ClassDescriptor> descriptorMap = event.getSession()
				.getDescriptors();
		Set<Entry<Class, ClassDescriptor>> entries = descriptorMap.entrySet();

		for (Entry<Class, ClassDescriptor> entry : entries) {

			Class cls = entry.getKey();
                        // getUserDefinedTypeMap = my refelction based method that creates a map of attribute name to java type based on a marker interface
			Map<String, Class> attributeTypeMap = getUserDefinedTypeMap(cls);

			ClassDescriptor desc = entry.getValue();

			Vector<DatabaseMapping> mappings = desc.getMappings();
			for (DatabaseMapping mapping : mappings) {

				if (mapping instanceof DirectToFieldMapping) {
					DirectToFieldMapping dfm = (DirectToFieldMapping) mapping;
					if (attributeTypeMap
							.containsKey(mapping.getAttributeName())) {
						// set the converter to null
						dfm.setConverter(null);
						// set the field type to STRUCT
						dfm.setFieldType(java.sql.Types.STRUCT);
					}

				}
			}

		}
}