public static Long positive(@Nullable String role, Long x) {
		if (x.longValue() <= 0) {
			throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
		}
		return x;
	}
public static Long positive ( @ Nullable String role , Long x ) { if ( x . longValue ( ) <= 0 ) { throw new IllegalArgumentException ( role + " (" + x + ") must be > 0" ) ; } return x ; }
校验为正数则返回该数字，否则抛出异常.