code: public static String findAttributeName( SimpleFeatureType featureType, String field ) {
          List<AttributeDescriptor> attributeDescriptors = featureType.getAttributeDescriptors();
          for( AttributeDescriptor attributeDescriptor : attributeDescriptors ) {
              String name = attributeDescriptor.getLocalName();
              if (name.toLowerCase().equals(field.toLowerCase())) {
                  return name;
              }
          }
          return null;
      }
docs: Find the name of an attribute, case insensitive.
  
  @param featureType the feature type to check.
  @param field the case insensitive field name.
  @return the real name of the field, or <code>null</code>, if none found.