Internal ID of CustomFieldRef

    CustomFieldList cfl = customrec.getCustomFieldList();     CustomFieldRef[] cfr = cfl.getCustomField();     StringCustomFieldRef bankgironummer = null;             for (int i = 0; i < cfr.length; i++) {      bankgironummer = (StringCustomFieldRef) cfr[i];      if (bankgironummer.getInternalId().equals("custrecord_bankgironummer")) {       break;      }     }   

My problem is that I want to be able to loop through cfr (an array of CustomFieldRef objects) and get their Internal IDs. When it matches with the desired Internal ID, I want to break.

I have not been able to find a method to get the Internal ID for a CustomFieldRef, so I'm forced to cast the object into a StringCustomFieldRef. This works fine as long as the Custom Field is a FreeForm Text field, but when I have other fields, for example a Custom Field with Integer it doesn't work.