title: Android Handlers - inter-thread communication
body: <p>How do you implement two-way communication between two threads with Handlers in Android?</p>
  
  <p>I have a Service A that spawns thread B. It's fairly easy to communicate from B to A, it's just to pass a Handler to the constructor of B, but how to do it from A to B? B does not have any Looper assigned to it automatically.</p>
  
  <p>Has anyone got the answer?</p>