space in sourceforge download link

[c-s at c-s.li]

I am trying to create a new port from a distfile in sourceforge. My problem
is that the download link has a space and brackets which do not seem to
work. What I am doing wrong?

Here is the supposed part of Makefile: 

PORTNAME=       traveling_salesman
PORTVERSION=    1.0.2
PORTEPOCH=      1
CATEGORIES=     astro java graphics
MASTER_SITES=   SF
MASTER_SITE_SUBDIR=
travelingsales/${PORTNAME}%20%28stable%29/v.${PORTVERSION}
DISTNAME=       traveling_salesman-${PORTVERSION}
EXTRACT_SUFX=   .jar
EXTRACT_ONLY=   #