That is, the locations returned by
Can other apps of a certain privilege level access these directories?
getExternalCacheDir() is accessible by any app that holds the
getCacheDir() is accessible only by your app, with the exception being on rooted devices where the user explicitly uses an app that leverages superuser capabilities to access the entire filesystem. However, any app can trigger the system to clear out the cache, so to some extent, any app can have delete privileges for
getCacheDir(). If that concerns you, use
Does the phone need to be rooted to access these?
getCacheDir(), yes (excluding the clear-cache scenario described above). For