DELIMITER $$
CREATE PROCEDURE increment_receipt_counter
(
   IN userID_in INT
)
BEGIN
    UPDATE User SET receiptCounter = receiptCounter + 1 WHERE id = userID_in;
    SELECT receiptCounter AS receiptCounter_new FROM User WHERE id = userID_in;
END
$$
DELIMITER ;

import javax.persistence.EntityManager;
import javax.persistence.StoredProcedureQuery;
...
public int incrementReceiptsCounter(int userID) throws InvalidEntityException, UnauthorizedException
{
    StoredProcedureQuery q = entityManager.createStoredProcedureQuery("increment_receipt_counter");
    q.registerStoredProcedureParameter("userID_in", Integer.class, ParameterMode.IN);
    q.setParameter("userID_in", userID);
    q.executeUpdate();
    return (Integer)q.getSingleResult();
}