The distance between Jakarta and Bandung are about 143km and Whoosh can travel between them for only around 45 minutes.
There is also a plan to extend this to go to Surabaya through Yogyakarta, but this isn’t clear yet.
Image taken from Wikimedia: https://commons.wikimedia.org/wiki/File:Whoosh_High-speed_Train,_from_Halim_to_Tegalluar,_Over_Kopo.jpg#/media/File:Whoosh_High-speed_Train,_from_Halim_to_Tegalluar,_Over_Kopo.jpg
I love rail in general, but this is debt diplomacy, albeit on better terms than the Chinese usually give.