Question

I am comfortable with actionscript. When I wantet to have network access for example in air, I coded the request and waited for the EventListener to kick in.

At the moment I’m doing a java tutorial with the following android code (wrapped in a try/catch):

url = new URL("http://www.google.com");
URLConnection conn = url.openConnection();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream());
String line = '';
while((line = reader.readLine()) != null) {
     // do something with the line
}

I don’t get how this works.

Why is there no eventListener needed? If the code proceeds immidiately after the URL is requested, the URL may not been retrieved when the while-Construct kicks in.

Is the app just paused in the meantime? If yes, is it possible to realise this with an eventlistner?

Thank you for help!

Answer 1

Is the app just paused in the meantime?

Yes. The regular Java IO classes are synchronous. The call to readLine() will block until either it can return a line or there’s an Exception.

If yes, is it possible to realise this with an eventlistner?

Yes, by using classes in the java.nio package. But only with a somewhat lower-level interface.

In general, Java applications use multithreading instead of event qeueues to deal with such sitatuations.