public static String format(Integer i) {

        // Return null if no value provided
        if (i == null)
            return null;

        // Convert to string
        return i.toString();

    }
Formats the given integer in the format required by a numeric field.

@param i
    The integer to format, which may be null.

@return
    A string representation of the given integer, or null if the given
    integer was null.
guacamole-ext/src/main/java/org/apache/guacamole/form/NumericField.java