title: How can I get informations within code about the cache of my app?
body: <p>I want to check where my apps cache is raising all the time. 
  So I need a method to access informations about the current cache at any time. 
  I think there must be such a method, because I could see the size of the cache in the App-Info of my android-smartphone.
  The app is running in the background and I want to log when the size of the cache is raising.</p>