<p>How do you detect if <code>Socket#close()</code> has been called on a socket on the remote side?</p>

The
```
isConnected
```
method won't help, it will return
```
true
```
even if the remote side has closed the socket. Try this:
```
```
public class MyServer {
    public static final int PORT = 12345;
    public static void main(String[] args) throws IOException, InterruptedException {
        ServerSocket ss = ServerSocketFactory.getDefault().createServerSocket(PORT);
        Socket s = ss.accept();
        Thread.sleep(5000);
        ss.close();
        s.close();
    }
}

public class MyClient {
    public static void main(String[] args) throws IOException, InterruptedException {
        Socket s = SocketFactory.getDefault().createSocket("localhost", MyServer.PORT);
        System.out.println(" connected: " + s.isConnected());
        Thread.sleep(10000);
        System.out.println(" connected: " + s.isConnected());
    }
}
```
```
Start the server, start the client. You'll see that it prints "connected: true" twice, even though the socket is closed the second time.
The only way to really find out is by reading (you'll get -1 as return value) or writing (an
```
IOException
```
(broken pipe) will be thrown) on the associated Input/OutputStreams.