Throw an Exception if Not Found

    /**
     * Typical DAO/Service layer finder method.
     * If unable to find the Object from the ID, 
     * throw an Exception instead of returning null. 
     */
    public Object findById(BigDecimal id) 
        throws NotFoundException, FindException {
        try {
            ResultSet resultSet = preparedStatement.executeQuery();
            if (resultSet.next()) {
                Object obj = new Object();
                // populate the object...
                return obj;
            }
            // throw a runtime exception instead of returning a null object
            throw new NoSuchElementException("Object not found for ID: " + id);
        } catch (SQLException e) {
            throw new FindException(e);    
        }        
    }

See: Diagnosing Java Code: The Null Flag bug pattern