public SocketServer(File directory) 
{
    this.dir = directory;
    hierarchyMap = new Hashtable(11);
}

 LoggerRepository configureHierarchy(InetAddress inetAddress) 
{
    cat.info("Locating configuration file for "+inetAddress);
    // We assume that the toSting method of InetAddress returns is in
    // the format hostname/d1.d2.d3.d4 e.g. torino/192.168.1.1
    String s = inetAddress.toString();
    int i = s.indexOf("/");
    if(i == -1) {
      cat.warn("Could not parse the inetAddress ["+inetAddress+
	       "]. Using default hierarchy.");
      return genericHierarchy();
    } else {
      String key = s.substring(0, i);
      File configFile = new File(dir, key+CONFIG_FILE_EXT);
      if(configFile.exists()) {
	Hierarchy h = new Hierarchy(new RootLogger(Level.DEBUG));
	hierarchyMap.put(inetAddress, h);
	new PropertyConfigurator().doConfigure(configFile.getAbsolutePath(), h);
	return h;
      } else {
	cat.warn("Could not find config file ["+configFile+"].");
	return genericHierarchy();
      }
    }
}

 LoggerRepository genericHierarchy() 
{
    if(genericHierarchy == null) {
      File f = new File(dir, GENERIC+CONFIG_FILE_EXT);
      if(f.exists()) {
	genericHierarchy = new Hierarchy(new RootLogger(Level.DEBUG));
	new PropertyConfigurator().doConfigure(f.getAbsolutePath(), genericHierarchy);
      } else {
	cat.warn("Could not find config file ["+f+
		 "]. Will use the default hierarchy.");
	genericHierarchy = LogManager.getLoggerRepository();
      }
    }
    return genericHierarchy;
}

 static  void init(String portStr,
    String configFile,
    String dirStr) 
{
    try {
      port = Integer.parseInt(portStr);
    }
    catch(java.lang.NumberFormatException e) {
      e.printStackTrace();
      usage("Could not interpret port number ["+ portStr +"].");
    }
    PropertyConfigurator.configure(configFile);
    File dir = new File(dirStr);
    if(!dir.isDirectory()) {
      usage("["+dirStr+"] is not a directory.");
    }
    server = new SocketServer(dir);
}

 public static  void main(String[] argv) 
{
  
    if(argv.length == 3)
      init(argv[0], argv[1], argv[2]);
    else
      usage("Wrong number of arguments.");
    try {
      cat.info("Listening on port " + port);
      ServerSocket serverSocket = new ServerSocket(port);
      while(true) {
	cat.info("Waiting to accept a new client.");
	Socket socket = serverSocket.accept();
	InetAddress inetAddress =  socket.getInetAddress();
	cat.info("Connected to client at " + inetAddress);
	LoggerRepository h = (LoggerRepository) server.hierarchyMap.get(inetAddress);
	if(h == null) {
	  h = server.configureHierarchy(inetAddress);
	}
	cat.info("Starting new socket node.");
	new Thread(new SocketNode(socket, h)).start();
      }
    }
    catch(Exception e) {
      e.printStackTrace();
    }
}

 static  void usage(String msg) 
{
    System.err.println(msg);
    System.err.println(
      "Usage: java " +SocketServer.class.getName() + " port configFile directory");
    System.exit(1);
}