Socket doen't detect broken network.

Question

the following server program just keeps on running when I unplug the clients network kabel. (client is just a telnet)
If I send to the socket outputstream he doesn't detect the broken link.
jdk 1.4.1
linux.
java.net.ServerSocket serverSocket= new java.net.ServerSocket(3201);
java.net.Socket socket = serverSocket.accept();
java.io.DataOutputStream lS = new java.io.DataOutputStream(socket.getOutputStream());
while(true)
lS.writeUTF("test");
lS.flush();
System.out.println("testing");
Thread.sleep(1000);
}

Answer 1

yep, pain in the neck isnt it...
reason is that TCP/IP is not a permanent type of connection, rather a serise of packets between 2 sockets, if you terminate the connection "properly" then an EOF is sent by the closing Socket, if however there is a network failure then it can never be recieved The expected work around is with Socket.setSO_TIMEOUT, but this has been reported to be unreliable and the standard method for detecting a broken connection is to write your own timeout and either close the socket, or attempt to write something to it (which will throw an IOException) if it has failed