I have a simple question: if I use URLConnection.setUseCaches(true) when loading something from web, when will those cached files expire? I'm developing for android, but it hardly makes any difference... So when will cache files be removed from SD card?
This question's answer suggests that URLConnection.setUseCaches(true) has no effect.
What Neil then describes is how Android apps stored internally (phone memory) can also have cached content, held in /data/data/packagename/cache. To answer your original question but applied to this feature, the system is ultimately in control of these areas, although you are supposed to look after your own content, as described in the API.