Looking at bikepedia.com I looked at the 2003, 2009 & 2015 versions of your bike, since you didn't specify a year.
They all used 14 ga. spokes.
Any bike shop should have those, since they are basically "THE" generic spoke.
My LBS charges $1 spoke for those.

BTW, IF the spoke broke in the J bend AND you break another spoke in the relative near future, get the wheel re-spoked.
Spokes are like pop corn. The start off slow and then rapidly increase "popping".