Create listener for server socket response?

I have a server-client pair and I want to create a listener on the client end for new server responses. I am not sure how to do this, right now I can only interact in a direct synchronous way.

Here is the server:

public class TestServer {

public static void main(String[] args) throws Exception {

    TestServer myServer = new TestServer(); 
    myServer.run(); 

}

private void run() throws Exception {

    ServerSocket mySS = new ServerSocket(4443);     

    while(true) {

        Socket SS_accept = mySS.accept(); 

        BufferedReader myBR = new BufferedReader(new InputStreamReader(SS_accept.getInputStream()));

        String temp = myBR.readLine(); 
        System.out.println(temp); 


        if (temp!=null) {

            PrintStream serverPS = new PrintStream(SS_accept.getOutputStream()); 
            serverPS.println("Response received: " + temp); 

        }

    }
}

}

As you can see, it sends a response when it gets one. However in general I won't be sure when other servers I use send responses, so I would like to create an asynchronous listener (or at least poll the server for a response every half-second or so).

Here is what I'm trying on the client end:

protected static String getServerResponse() throws IOException {

    String 开发者_运维知识库temp;
    try {
        BufferedReader clientBR = new BufferedReader(new InputStreamReader(mySocket.getInputStream())); 
        temp = clientBR.readLine(); 
    } catch (Exception e) {
        temp = e.toString(); 
    }

    return temp; 
}

And just for reference, yes, sending over data from client to server works fine (it System.out's the data correctly). However, when I call the above function to try and retrieve the server response, it just hangs my application, which is an Android application in case that's relevant.

What I want from a function is just the ability to ask the server if it has data for me and get it, and if not, then don't crash my damn app.

On the client side create a ConnectionManager class which will handle all the socket I/O. The ConnectionManager's connect() method will create and start a new thread which will listen for server responses. As soon as it will receive a response it will notify all the ConnectionManager's registered listeners. So in order to receive asynchronously the server responses you will have to register a listener in ConnectionManager using its register(SomeListener) method.

Also, you can have a look at JBoss Netty which is an asynchronous event-driven network application framework. It greatly simplifies and streamlines network programming such as TCP and UDP socket server.