public void closeClient(String user) { Handler client = (Handler) handlers.get(user); client.sendStop(); try { client.close(); } catch (IOException ex) { Logger.getLogger(EchoServer.class.getName()).log(Level.SEVERE, null, ex); } handlers.remove(user); sendOnlineUsersMsg(); Logger.getLogger(EchoServer.class.getName()) .log(Level.INFO, "Closed a client", new Object[] {client.getUsername()}); }