private void accept(){
        Socket clientSocket = null;
        try {
            clientSocket = serverSocket.accept();
        }catch (SocketException e){
            if(running){
                LOG.fatal("server socket error", e);
                System.exit(-1);
            }
        } catch (IOException e) {
            LOG.fatal("ServerSocket accept error", e);
            System.exit(-1);
        }
        new Thread(new ProcessReceiver(clientSocket)).start();
    }