// Set the combined custom field values.
lineItem.setCustomFieldValues(combinedCustomFieldValues.toArray(new BaseCustomFieldValue[]{}));
// Update the line item on the server.
LineItem[] lineItems = lineItemService.updateLineItems(new LineItem[] {lineItem});
for (LineItem updatedLineItem : lineItems) {
// Get a string representation of the custom field values.
List<String> customFieldValueStrings = Lists.transform(
Arrays.asList(updatedLineItem.getCustomFieldValues()),