Cannot get http server work on android

Question

I have a http server code (I tried both TJWS or NanoHTTPD), the client from the same application would connect to server running on port 8080 or whatever.

I am starting server object in a separate AsyncTask so it should be okay.

While NanoHTTPD completely failed to start other ways I can see from TJWS logs, it says something like;

server listening on 0.0.0.0/0.0.0.0 port:0 localport:8080

This means server started successfully, first question is 0.0.0.0 bind address acceptable? I mean it should be 127.0.0.1 instead? sorry if that is a noob question.

When I connect to my emulator using adb shell and run netstat, I can see the following lines

Proto Recv-Q Send-Q Local Address          Foreign Address        State
 tcp       0      0 127.0.0.1:5037         0.0.0.0:*              LISTEN
 tcp       0      0 0.0.0.0:5555           0.0.0.0:*              LISTEN
 tcp       0      0 10.0.2.15:5555         10.0.2.2:52132         ESTABLISHED
tcp6       0      0 :::8080                :::*                   LISTEN

By googling I learned that 0 :::8080 means server is listening on ipv6 and ipv4 both and that is okay.

But from my client code when i tried to access it continues to wait for eternity.

my httpClient Code

   try {
        URL url = new URL("http://0.0.0.0:"+8080+"/media");
        URLConnection conn = url.openConnection();
        InputStream is = conn.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        String line;
        while((line = br.readLine()) != null){
            Log.d("server", line);
        }
    } catch (MalformedURLException e) {

        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

Answer 1

For the server, the address 0.0.0.0 is like a wildcard and means, it is listening on all IP addresses the device has.

For the client, you need to use a real IP address like 127.0.0.1

Answer 2

After debugging a little I found that problem is not where client opens a connection but issue was at where server was starting it never returned onPostExecute() method, but after wrapping my server start code inside a Runnable

  new Thread(new Runnable() {

        @Override
        public void run() {
            Log.d("server", "server starting on port: " + port);
            srv.serve();
        }
    }).start();  

it Works!!

Server is a infinite loop so does it have to be started from inside thread? I thought AsyncTask can handle that?

Its also worth mentioning that client side connection must also be wrapped inside AsyncTask