How to detect a remote side socket close? [duplicate]

by

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.

More Related Contents:

  1. Java TCP socket: data transfer is slow
  2. java.net.ConnectException: Connection refused
  3. java.net.SocketException: Connection reset
  4. Java socket API: How to tell if a connection has been closed?
  5. Does a TCP socket connection have a “keep alive”?
  6. Why is it impossible, without attempting I/O, to detect that TCP socket was gracefully closed by peer?
  7. Asynchronous IO in Java?
  8. how to achieve transfer file between client and server using java socket [duplicate]
  9. How to find an available port?
  10. How do I check if a Socket is currently connected in Java? [duplicate]
  11. How to avoid a NoRouteToHostException?
  12. Java HttpURLConnection and pooling
  13. Socket using in a swing applet
  14. Getting the ‘external’ IP address in Java
  15. Query ARP cache to get MAC ID
  16. java.net.ConnectException :connection timed out: connect?
  17. how to get a client’s MAC address from HttpServlet?
  18. Check for Active internet connection Android
  19. java.io.StreamCorruptedException: invalid type code: 00
  20. Java: no security manager: RMI class loader disabled
  21. Can TCP and UDP sockets use the same port?
  22. Bluetooth Connection failed “java.io.IOException: read failed, socket might closed or timeout, read ret: -1”
  23. java read file from network device
  24. How to send and receive serialized object in socket channel
  25. Java Server – Multiple ports?
  26. Sending and receiving files on socket
  27. Using Sockets to send and receive data
  28. Is binding to 0.0.0.0 in Java guaranteed to bind to all network interfaces?
  29. ObjectInputStream(socket.getInputStream()); does not work
  30. How to close a socket left open by a killed program?

Leave a Comment