Spring DefaultConversionService

public DefaultConversionService() {
   addDefaultConverters(this);
}

	public static void addDefaultConverters(ConverterRegistry converterRegistry) {
		addScalarConverters(converterRegistry);
		addCollectionConverters(converterRegistry);

		converterRegistry.addConverter(new ByteBufferConverter((ConversionService) converterRegistry));
		converterRegistry.addConverter(new StringToTimeZoneConverter());
		converterRegistry.addConverter(new ZoneIdToTimeZoneConverter());
		converterRegistry.addConverter(new ZonedDateTimeToCalendarConverter());

		converterRegistry.addConverter(new ObjectToObjectConverter());
		converterRegistry.addConverter(new IdToEntityConverter((ConversionService) converterRegistry));
		converterRegistry.addConverter(new FallbackObjectToStringConverter());
		converterRegistry.addConverter(new ObjectToOptionalConverter((ConversionService) converterRegistry));
	}

public static ConversionService getSharedInstance() {
   DefaultConversionService cs = sharedInstance;
   if (cs == null) {
      synchronized (DefaultConversionService.class) {
         cs = sharedInstance;
         if (cs == null) {
            cs = new DefaultConversionService();
            sharedInstance = cs;
         }
      }
   }
   return cs;
}