private void configureDateFormat(Jackson2ObjectMapperBuilder builder) {
   // We support a fully qualified class name extending DateFormat or a date
   // pattern string value
   String dateFormat = this.jacksonProperties.getDateFormat();
   if (dateFormat != null) {
     try {
       Class<?> dateFormatClass = ClassUtils.forName(dateFormat, null);
       builder.dateFormat((DateFormat) BeanUtils.instantiateClass(dateFormatClass));
     } catch (ClassNotFoundException ex) {
       builder.dateFormat(new SimpleDateFormat(dateFormat));
     }
   }
 }