// Get the AdGroupCriterionService.
AdGroupCriterionServiceInterface adGroupCriterionService =
adWordsServices.get(session, AdGroupCriterionServiceInterface.class);
// Create base class criterion to avoid setting keyword specific fields.
Criterion criterion = new Criterion();
criterion.setId(criterionId);
// Create ad group criterion.
AdGroupCriterion adGroupCriterion = new AdGroupCriterion();
adGroupCriterion.setAdGroupId(adGroupId);
adGroupCriterion.setCriterion(criterion);