private final void processArgs(String[] args) {
        boolean success = false;
        if (args[0].length() < 1) {
            return;
        }

        Invokable method = commandMap.get(args[0]);
        if (method == null) {
            out.println("\nunknown command: " + args[0]);
        } else {
            success = method.invoke(args);
            if (!success) {
                out.println("operation failed.");
            }
        }
    }