CODEWITHSUNDEEP
androidsockets
Josef
Josef

Reputation: 2726

Android application is freezed - Socket Exception

I made android application that connects to remote server and send some data. Remote server is Windows application.

Connection method:

private void ConnectToMonitor() {
    try {
        s = new Socket(SERVER_ADDRESS, TCP_SERVER_PORT);
    } catch (UnknownHostException e) {

        e.printStackTrace();
    } catch (IOException e) {

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

This works perfectly if server is online. Application is sending data and server is receiving. But if server is offline android app. is blocked. My question is how to handle this? How to continue with application and avoid error even the server is down?

Upvotes: 2

Views: 731

Answers (3)

ehanoc
ehanoc

Reputation: 2217

First remember to set the socket timeout : 

mSocket.setSoTimeout(timeout); //in milliseconds

You can however specify different timeout for connection and for all other I/O operations through the socket:

private void connectToMonitor() {
    try {
        socket = new Socket();            
        InetAddress[] iNetAddress = InetAddress.getAllByName(SERVER_ADDRESS);
    SocketAddress address = new InetSocketAddress(iNetAddress[0], TCP_SERVER_PORT);

        socket.setSoTimeout(10000); //timeout for all other I/O operations, 10s for example
        socket.connect(address, 20000); //timeout for attempting connection, 20 s
    } catch (UnknownHostException e) {

        e.printStackTrace();
    } catch (IOException e) {

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

Second, in Android, you should perform any network I/O in separate threads!

As an example, using regular Java Threads : 

String threadName = getClass().getName() + "::connect";     
    new Thread(new Runnable() {         
        @Override
        public void run() {
            connectToMonitor();
        }
    }, threadName).start();

Upvotes: 2

Neron T
Neron T

Reputation: 369

Remember to call this outside the UIThread. Follow this tutorial. In android all connections need to be managed outside the UIThread, in the tutorial I linked you will find easy ways to post your results back to the UI (handlers, asynctasks...)

Of course we don't know if the problem is about the thread with just the given code, but it is the most usual error.

Upvotes: 3

stinepike
stinepike

Reputation: 54672

You can set A timeout for the socket. Use Socket.setSoTimeout method

socket.setSoTimeout(timesinmilis);

by using this your socket will throw a socket timout exception. You can catch that and do what you want

Upvotes: 0

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