title: Define a map as constant in java
body: <p>For my Android app I've the need of defining some keys in a single constant, and I think the best way to do it is using a map. But not sure whether that's really the way to go, and how to do it correctly. As I'm targeting Android, a Bundle may also be an option.</p>
  
  <p>I have a list of keys like:
  <br>"h" = "http"
  <br>"f" = "ftp"</p>
  
  <p>Basically the program is to read a QR code (to keep that code from growing too big I'm using super-short keys), gets those keys, and has to translate them to something useful, in my case a protocol.</p>
  
  <p>I'm trying to define a constant called KEY_PROTOCOLS, I think this should be a Map, so later I can call something like KEY_PROTOCOLS.get("f") to get the protocol that belongs to key "f". </p>
  
  <p>Other classes should also be able to import this constant, and use it. So this map has to be populated in the class right away.</p>
  
  <p>How can I do this?</p>