Android bufferedReader.readLine for continuously listening

问题

I'm trying to write a demo-app that connects to a server and then simply keeps listening for randomly timed input from the server. Discovering the and connecting to the server works fine, now I start a new thread, so I don't block the ui. Now, in my thread, I need to continuously listen and react if there's incoming data. According to what I've read so far, it should be done like that:

  while (connected) {
      while ((line = bufferedReader.readLine()) != null) {
          // do something with line and contact the ui
      }
  }

What I don't understand: readLine() obviously can only read a line if there's incoming data from the server. So, shouldn't the loop break once the server has stopped sending, meaning when there's nothing sent?

Thanx for any thought, Marcus

回答1:

readLine is a blocking method, so if nothing is being received, it will wait blocking execution right there. Loop will only stop when a null value is received (when reading a text file this tipically means that the end of file has been reached).

Try to detect closed connections in a different way, or if you also code the server, try sending something like "END", which can be read at the client.

来源：https://stackoverflow.com/questions/11359650/android-bufferedreader-readline-for-continuously-listening