UserParameter.java

/*
* Class used to filter the User entity
*/
public class UserParameter {
	private String userId;
	private String lastName;
	/* only last 4 digits */
	private String ssn;
	// getters and setters
}

UserRepo.java

/*
* Matches either on userId or lastName + last4 digits of SSN
*/
public List<User> findAllByUserIdOrLastNameLastFourSSN( List<UserParameter> parameters ) {
	  
	// setup the criteria API to query User
	CriteriaBuilder cBuilder = getEntityManager().getCriteriaBuilder();
	CriteriaQuery<User> criteriaQuery = cBuilder.createQuery(User.class);
	Root<User> root = criteriaQuery.from(User.class);
	criteriaQuery.select(root);

	// set up lists to store the userId or predicates to match lastName AND last 4 of ssn
	List<String> userIds = ArrayList<>();
	List<Predicate> nameAndSSNPredicates = new ArrayList<>();

	// Loop over parameters, adding predicates and parameters as needed
	int i = 0;
	for(UserParameter param : parameters) {
	  
	  if(null == param.getUserId) {
	    // match lastname + ssn with unique parameters
	    Predicate predicate = cBuilder.and(
	      ParameterExpression<String> lastNameParam = cBuilder.parameter(String.class, "lastName" + i);
				ParameterExpression<String> ssnParam = cBuilder.parameter(String.class, "ssn" + i);
				cBuilder.equal(root.get("lastName"), lastNameParam),
				cBuilder.equal( cBuilder.substring(root.get("ssn"), cBuilder.diff( cBuilder.length( root.get("ssn") ), 3), cBuilder.literal(4) ), ssnParam)
			);
			nameAndSSNPredicates.add(predicate);
	  } else {
	    // match to userId
	    userIds.add(param.getUserId);
	  }
	  
	}

	// Add userIds to list of predicates
	if(!userIds.isEmpty()) {
	  nameAndSSNPredicates.add(root.get("userId").in(userIds));
	}

	// seperate all generated predicates with an OR
	Predicate combinedPredicate = cBuilder.or(nameAndSSNPredicates.toArray(new Predicate[nameAndSSNPredicates.size()]));

	// Create Query and add parameters
	criteriaQuery.where(combinedPredicate);
	Query query = getEntityManager().createQuery(criteriaQuery);

	int x = 0;
	for(UserParameter param : parameters) {
	  if(null == param.getUserId) {
	  // only set parameters for lastname and ssn matches
	      query.setParameter("lastname" + x, param.getLastName());
	      query.setParameter("ssn" + x, param.getSsn());
	  } 
	  x++;
	}

	// run the query
	return query.getResultList();
		
}