title: How to send message to an activity asynchronously in android?
body: <p>My application works as follows:
  There is an Application class (derived from android.app.Application class) for receiving data from the network and dispatch these data to the corresponding activity.</p>
  
  <p>The problem is:
  There is a possibility that when activity A starts activity B, there maybe network data received by my Application object, and I want to send this data to activity B which may be not started yet, how could the app guarantee that activity B receive this data? Are there any asynchronous message passing mechanism or should I manually cache the message until activity B start?</p>